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> How to Turbo your 5S-FE, A Complete Walk-Through
post Aug 23, 2003 - 3:14 AM
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Alright, this is all you should need to know when turboing your 5S-FE. First and foremost, please read these FAQs and once you are familiar with the setup, you can continue.

presure2's 5sfte post
Turbocharger Project from Scrap for Do-It-Yourselfers
How a Turbocharger Works
Turbo Power Calculator
Fuel Injector Mapping <- For if you want to have your injectors cleaned and mapped.
Burien Toyota <- Burien's 5S-FE Turbo Kit Information
turbo glossary and calculations turbo glossary and calculations

Ok, now that you have read and have an understanding of what is involved you may continue.

Basic Parts List
  • 3S-GTE Exhaust Manifold
  • 3S-GTE CT-26 Twin Entry Turbocharger
  • 3S-GTE Downpipe
  • 3S-GTE Oil Pan and Oil Drain Lines
  • 3S-GTE 2 Bar MAP Sensor
  • Custom Coolant Lines
  • Custom Oil Feed Line and steel "T" Fitting
  • Spark Plugs such as Denso IK22 or NGK BKR7EVX-11 <- These must be regapped to All-Trac gap, which is .030!
Recommended Parts[list]
[*]Misc Gauges (boost, oil pressure, EGT) <- Allows you to keep an eye on the engine's functions.
[*]Aftermarket Clutch <- Allows you to get all the power to the ground, where it's suposed to be.
[*]Intercooler <- Cools the air before entering the throttle body. A must with over 7 psi or so.
[*]Boost Controller <- You don't want to over boost.
[*]'98+ Camry Metal Head Gasket
[*]A'pexi S-AFC(2)/Greddy E-Manage <- Helps to control the fuel curve.
[*]ARP head bolts <- Don't want to loose your head.
[*]LSD(TRD, Kaaz, Cusco or Quaife) <- Allows you to transfer your power to the ground better.

Useful Info to Know

There are 2 kinds of CT-26 turbochargers. The first one came in the ST165(fourth generation All-Trac/GT-Four) Celica(with the 3S-GTE engine) and the MKIII Supra(with the 7M-GTE engine.) This is a single entry turbo. The second type is from the ST185(fourth generation All-Trac/GT-Four) Celica and the MK2 MR2 Turbo(SW20 chassis.) It is a dual entry turbo. The dual entry has a faster and stronger spool. The manifolds from these turbos can not be interchangeable, so if you have a single entry turbo you must use the matching manifold and so on and so forth.

If you're maybe getting parts from a 7M-GE supra, you might want to also take the intercooler. An intercooler is a nice touch for your turbo kit, and you'll just need to get some custom piping done, which should be relatively inexpensive. If you feel like doing it yourself, just get some hose clamps and various U-bends and other pipes. Try to keep your piping about 2 inches in diameter, as this will help for better throttle response.

As far as performence expectations, at about 8 or 9 PSI, your performance should be up to par with a Mustang GT or Eclipse GS-T/Talon TSI, at least at boost on the highway. With this particular turbo setup, you should gain between 9 and 11 hp for each PSI. But along with your custom piping, you're going to want to weld on a flange for a blow-off valve and then add the blow-off valve of your choice. A blow off valve will vent the air between the turbo and the throttle body into the atmosphere when the throttle body is closed, like when you're shifting. If compressed air is trapped because it can't vent into the atmosphere and can't go into the throttle body, it can only go one place...back into the turbo, which can cause compressor surge, which can damage the turbo and keep it from continuing to spool between shifts.

Also, you will need some kind of custom exhaust. You can go with the Greddy SP cat-back system, and it will work with your setup just fine. The diameter of the Greddy SP's piping is optimized for the N/A 5S-FE however, and not for a turbocharged 5S-FE. I would recommend going as high as 3 inches, because back pressure is not a problem on a turbocharged car. I recommend custom piping and a good free-flowing muffler, but make sure you get mandrel bends and not crush bent piping if you want optimal flow.

If you are planning on swapping out your head gasket, make sure you do it right the first time. There is a lot of work tied up in removing the head. Some of the things that have to go are the alternator, all coolant lines(Drain the coolant of course, Toyota uses the red kind so dont fret over it not being green.), the wiring harness and all nesessary plugs, vacuum hoses, and wires. The '98+ Camry head gasket is metal, but from what I hear from my guys at Toyota, all replacement head gaskets are metal now. Be sure you have a Chilton's or Toyota hand book on hand at all times. Get your head milled once you have it removed, because it should only be $20 to $40. Due to heat reasons, there is a good chance it will be warped a bit, but be sure not to mill more than 20/1000 or the head will not seal. When re-installing the head, the torque is 36 lbs. + a 90 degree turn, this should be made by 1 full rotation of 45 degree turns and then another 45 degrees.

Basic Installation

First drain the oil pan. Assuming you have a aftermarket intake, remove it now. If you cannot figure that out please turn back from this project! While the oil pan is draining, remove the 6 14mm nuts holding the exhaust manifold on the head and the 3 14mm nuts holding the header to the exhaust.
Now that that is done, your pan should be empty, so remove the oil pan and its 15 10mm bolts (2 are nuts.) To get the oil pan off you first have to unbolt the tranny heat shield that is in the way and the front motor mount. You have to push down very hard on the support the mount was once attached to to get the pan out. You'll undertstand this once you see it. Now place the 3S-GTE oil pan in its place in the reverse order. Next, Remove the valve cover by pulling the 4 spark plug wires and removing the 4 30mm nuts holding the valve cover down. Tap the cover with a rubber mallet if needed to break the seal. Now you can the see the injectors and fuel rail behind the head. Unsnap the plugs and remove the 2 bolts holding the rail in place. Install the 7M-GE injectors in the rail and back into the head. Replace the 2 bolts and torque them down to 9lbs. Reinstall the valve cover and install your new spark plugs and torque them down to 12lbs. Be sure you have gapped them to .030! If you fail to do so your engine will detonate at exactly 5 pounds of boost!

This is a good time for a break..... Sit back and have a beer knowing that you are that much closer to boost than before.

Ok back to the car.

Now take the 3S-GTE exhaust manifold and the turbo and bolt them together using the 4 14mm nuts to hold it to the studs. Use the needed gaskets here. If you plan on using the coolant lines to the turbo you will need to tap into the the Throttle body heating lines. Look under the throttle body for the 2 3/8in coolant lines and use brass Ts here with hose clamps. Run the lines to the area that the turbo sits keeping them away from any high heat items. Install both the coolant lines and both oil lines to the turbo now using the correct gaskets. There is a round gray colored metal sensor with one wire and a rubber cover. You need to un-hook this wire and remove the sensor using a pair of channel locs. Take this sensor to the auto parts store and get the following items.

You'll need 1 T fitting with a male end the same thread as the sensor. The other 2 holes in the T don't matter, get an adaptor that will place the oil pressure sending unit in one of these holes.you can get one from www.tunertoys.com Take the assembly home and teflon tape all the fittings and install it in to the head. This is how you will feed fresh oil to the turbo. Place the new exhaust gasket on the 6 studs protruding from the head and now place the turbo/manifold assembly on the studs for installation. I had a problem with hitting one of the radiator fan support pieces here but an exacto knife took care of that. Using the 6 14mm nuts removed from the stock exhaust manifold, bolt up the 3S-GTE manifold. Hook up the oil suply line and coolant lines but leave the return line off for the moment. Now install the stock 3S-GTE downpipe with the correct gasket and 3 14mm nuts. I am using a KO racing DP here and have run into problems hitting the right side of the A/C lines. Nothing a little light welding can't fix. At the passenger side firewall there is a small black sensor with a vacuum line running to it. Remove it and install your 2 bar MAP sensor(part# 84420-17030) there.

Now its time to prime the engine. Locate the coil wire going to the cap and remove it. locate the EFI fuse in the relay box on the drivers side of the engine bay and remove that also. Double check all things are tight, nothing is in the way, and nothing will suck into the turbo. Just pay close attention to everything. Crank the car over for 1-2 minutes. Get out and see if oil has dripped from the turbo drain line. If not, keep cranking until it does. Once you have oiled the turbo you can install the rubber elbow from the drain tube to the oil pan and reinstall the coil wire. Install whatever intake plumbing you want now and the intercooler and blow-off valve of your choice.

Once you have everything on the way you want it check to be sure everything is tight and start the car. Let it idle for a bit to reach normal temperature. Shut the car off and double check that everything is ok. Now get out your timing light and set your timing to 8 degrees (10 is stock.)

Now go take a few low boost test drives to be sure of your work and then your are free to go burn some Mustangs and Camaros for bragging rights. biggrin.gif

If you have any questions, feel free to look me or Jay12-15psi or manny (presure2) up on AIM, or feel free to just PM either of us. Our screen names are below.

dawoodro02 (Jay)
bwilson gt (Me - Bryan)
presure2 (manny)


This post has been edited by presure2: Jun 4, 2009 - 7:03 PM

Member of Team 5sfTe
post Jul 14, 2004 - 1:45 PM
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Joined Jan 8, '04
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More Info on Turboing the 5S-FE

First off, props to 1bwilson for his other post above.

This article is not my own by any means, it is the cumulative work of many great minds off and on this site. I've taken information I could find all over this forum and others in an attempt to finally provide a DEFINITE thread on this kinda stuff, with all the new information in place. It's been my impression that in the months since ibwilson posted his thread, there has been an explosion in the interest of turbocharging the 5sfe engine; and many more things have been discussed and decided apon.

As many things were already explained in his article, I'm going to use this as a suppliment.

The CT26 Turbo
... should only be your first choice if you're running low on cash, can get one for free, etc etc. Many owners of the 3sgte engine in the GT4, or the Alltracs, or the MR2s have spent years complaining about the CT26. Mechanically, there's nothing wrong. Past 8 psi however, the CT26 just doesn't deliver the same efficiency gains that it does before 8 psi. I don't have a compression map for the CT26 to show you guys (if someone finds one, I'll edit this and add one in) but for now here's a turbo map for a Garrett T3 turbo:

As you can see, the Garret T3 turbo is in it's optimal pressure range between 9 lbs/min and 14 lbs per minute. It's a good idea to look at turbo maps, and when picking out a turbo, find one that's efficiency range closely matches the psi you plan to be running daily, with room for less (to help with turbo lag) and more psi (for those high boost periods smile.gif

Because you still might be confused, here's a howto on reading turbo compression maps and choosing the right one.

so the CT26 doesn't cut it over 8 psi- so what?
This is where something thats a small issue in the 3sgte's 2.0L engine, becomes a much larger issue for those of us with a 5sfe 2.2L engine.

QUOTE (97sccelica)
97sccelica's profile
the ct26 that comes on a mr2 or alltrac is fine for a mild setup, but even on the stock engine it runs out of breath a good amount before redline., and a 5sfe has more displacement, which means the turbo will have to work harder.

When I was first learning about Turbos, thats how he explained it, and he explained it pretty well. Our larger displacement causes the CT26 Turbo to run out of it's efficiency range faster than we'd like, moving our power band in the RPMs around and causing future PSI hp gains to be minimal.

The solution to the CT26 "problem"
Why, a slightly bigger turbo of course! A lot of the 7afte guys are running T3 turbos, and these will work just fine on our engines at 8 psi and above (as demonstrated by that compressor map), but it's also possible to use a T3/T4 turbo- which has room for greater gains in the higher end.

The smaller the turbo, the faster it will spool and get rid of turbo lag, but the less gains it will give back, and the less power higher up in the powerband. If the turbo is too small, you risk damaging it.

If the turbo is too large, your turbo lag will be very high, and you'll be unable to pick up speed. You might be nice on the highway; but from a stop you'd be VERY slow and losing to NA's all the time smile.gif

Turbo lag? wtf?

This, is a boost guage. Everything below the 0 on the guage is a measurement of the vacuum within the engine, or the turbo lag. Because turbos work by harnessing the exhaust gasses out of the engine- when the engine is only running at 600 RPMs, the turbo isn't really going to be spinning. Instead, the engine is back to it's old NA method of putting air into the engine- vacuum. Unfortunetly, instead of a foot long short ram intake, the engine now has to "suck in" air through many feet of piping, through an intercooler, and past a turbo fan thats more of a hinder at the slow speeds it's spinning than a benefit. Thus, when you're in vacuum, you're actually putting out less hp than you were when you were NA.

The engine doesn't really "suck in" air- rather its a pressure change caused by exhaust gasses leaving the combustion chamber of the engine- causing a pressure drop that atmospheric pressure on the outside moves in to fill.

Think of the movie Aliens- where Ripley opens the airlock to shoot the Alien queen out into space? Everything was being sucked through the airlock- especially air! Because of the pressure differentials. Gases always want to be an equidistant apart, and will move further and further apart so as to take up as much space as possible.

What I'm saying is, until you are able to push enough RPMs through the engine for the turbo to "spool" up to "speed" you're going to be below the 0, in vacuum. The moment you get above the 0 is the moment your engine becomes a true Force Intake- the turbo now has enough pressure to force air into the engine that the engine wasn't "asking for"

Its a good idea to do everything you can to minimize turbo lag; but you're still going to have it.

Its an even better idea to buy a lightweight flywheel, so you can zoom up to the "turbo spooling" rpms faster. Warning: with a lightweight flywheel, when you let off the gas, you will also zoom OUT of the "turbo spooling rpms" just as fast! Unless you're driving fast enough. ALSO Flywheels for our car are available in a variety of weights. Get one too light and you'll jump to 4000 RPMs in a second. THIS IS A BAD THING IN TRAFFIC. You shoot forward 50 feet, into the back of the car in front of you. So try and find one thats a happy medium ok?

Here's a Fidanza Aluminum Flywheel for $383.00

Automatics can buy a torque converter; which has a similar effect to the flywheel. Neither will increase your torque or hp, but they both can make it easier to access.

I'm sorry, but I don't know of any torque converters for the 5sfe automatic- does anyone have any links?

What's the deal with compression? Shouldn't my engine run better when it's in turbo lag if I have like, 14:1 compression? and even BETTER when I put more presuure on it with the turbo?

Compression is a technique used on NA cars to emulate a supercharger (while variable timing lift on the new GTSs is a way of emulating turbo's). The more compression you have, the more psi you're putting into the engine. Compression is wonderful; but the moment you stick an actual F/I on your engine, compression becomes too much. You'll be compressing air, and then compressing air again- dangerous, and it will lead to detonation if you pump too much PSI into the engine through the turbo.

You should be able to hold at low PSI levels with stock compression pistons though. But once you strat upping the boost- even to 8 psi, you're going to want to start considering lower compression pistons (if you're building an NA car, you want to use HIGHER compression pistons)

Solution: Buy lower compression pistols. THis will bog down any NA car, and slightly increase your turbo lag (I believe), but it allows you to run higher psi and therefore higher hp later on in the RPM range.

CP Pistons and Race Engineering have pistons for the 5sfe

Besides new pistons,
QUOTE (defgeph)
switching to a thicker head gasket will lower compression. and cutting the head would raise it

Fuel System
Or what seperates a ricer from a man

A "ricer" will turbo his entire car, spending lots of money to make it go really fast, and ignore the fuel delivery system, causing his car to go lean every now and then and blow a piston straight up through the hood when the various components of the system can no longer handle the demands of the engine. This isn't pleasant, and the ricer will usually then spend a thousand more dollars doing everything else to the engine BUT the fuel system, thinking it will solve the problem.

If you're running lean, upgrade the fuel system. If you're not running lean, upgrade the fuel system before you do.

For the 5sfte project, this is simple. Supra NA 360cc injectors, and a Supra TT fuel pump. You can get larger size injectors if your boost requires it, and you should also look into a Fuel Management Unit (FMU, at least I HOPE thats what that stands for). This will cover you up to 12 psi and beyond; a FMU and boost controller like the Apex'i Super AVCR will show you the current load on your injectors, and from there you can make a decision based on how large you need to go at your current psi level (if you're at 55% load, you're pretty friggin safe, if you're at 97% load, somethings going wrong or you need bigger injectors).

There also seems to be a lot of confusion about which injectors are the "green-tops". The following is a picture of them, and the flowtest data to confirm (thanks to presure2 for these):

Help! My GT transmission blew out with all this added hp!!!

HA HA!!! No seriously, I can't help you. Look in other threads about switching it out for a MR2 tranny, lexus tranny, solara tranny, etc etc etc.

A word about transmission. Auto transmissions don't loose boost pressure like a manual transmission. Sometimes, automatic cars will even GAIN boost pressure while shifting. This would give them an advantage.. except they have less gears and are slower. D'oh.

What about exhaust manifolds?

This is my favorite part about the entire 5sfte project- because 3sgte exhaust manifolds- get this BOLT RIGHT ON!!! It's like a dream come true. Make sure you get a manifold that will fit the turbo you want to use! A stock 3sgte manifold will bolt right onto the 5sfe engine, but it won't bolt right up to a T3 turbo. You have to either buy an adapter or a manifold designed to fit the turbo you want to use. I suggest the manifold thats designed for the turbo. ANY aftermarket 3sgte exhaust manifold will bolt on, and you can waste money like MAD on The C-one 3rd Gen 3sgte Ex Manifold for $1,408.00

or like the Brash Boy Tubular Exhaust Manifold for $1517.72

The headers are the first part of the exhaust system, and the exhaust system- because of how the turbocharger spools- is almost the most important part of a turbo system.

Other notes on exhaust

What size should it be?
Just go three inches. With an NA engine you have to worry about minimizing gas pressure while maximazing gas scavenging (two topics I WILL NOT GO INTO IN THIS ARTICLE) but with a turbo, your number goal is MAXIMIZING FLOW so the turbo spools faster. On this note, make sure all major bends are mandral bent and NOT crush bent, that your cat- if you choose to have one, is EXTREMELY high flow, that there are as few bends as possible, and that your muffler doesn't have any backpressure problems. This topic of maximizing flow is also why it's important to have a smoothly polished turbo manifold (on the inside at least) so that exhaust gases don't get disturbed by protrusions and errors in the molding process.

Because of this, I've personally ruled out a dual exhaust system. I really wanted one for the looks for a long time.. but to maximize flow, just do a straight back 3" pipe. I also recommend
Magnaflow Mufflers.. hell, if professional racers use them, why don't you? biggrin.gif

QUOTE (boostedk2)
TKO uses Magnaflow mufflers on their MR2 exhaust systems, dyno proven to boast the biggest WHP gain from any bolt on exhaust system

Rebuilt blocks

Stroker kits


Should I build an intercooler into my setup?

The answer to this question is always yes. 1bwilson has this to say on intercoolers:

QUOTE (1bwilson)
An intercooler is a nice touch for your turbo kit, and you'll just need to get some custom piping done, which should be relatively inexpensive. If you feel like doing it yourself, just get some hose clamps and various U-bends and other pipes. Try to keep your piping about 2 inches in diameter, as this will help for better throttle response.

Also, with an intercooler, BIGGER IS BETTER. Air is compressed by the turbocharger, and this makes that air extremely hot. The air then feeds into the intercooler, whose purpose is to cool the air after it was heated by the turbo. Cooler air takes up less space, so it has a higher pressure- higher psi smile.gif Helps with turbo lag, helps with maximizing PSI. This is why the intercooler is a good thing.

The intercooler works by having a very large surface area (all those mounds and bumps and protrousions and fins) that outside air is then exposed to. For many of us, a front mounted intercooler (FMIC) is the only option, because we don't have a vents in our hood to allow for the working of a top mounted intercooler (TMIC). That's ok, FMIC's tend to be more efficient anyway, and better. One of the first steps for many GT4 owners was to replace the TMIC with a FMIC. Efficiency is a measure of how well the intercooler cools down the air after it passes through the turbo. You can also imagine that at higher speeds, the FMIC intercooler really has a LOT of cold air hitting it. This is true, the TMIC not so much. You could buy a WRX style hood scoop tho, and you'd get pretty much the same effect.

But if you're going that far, why not just go 70s muscle car and have the turbocharger sticking up out of the hood? smile.gif

Just trust me when I say FMIC is better, ok?

As for WHAT FMICs to get, no company makes specific ones for our cars of course- with the exception of for the GT4. I believe Greddy makes a kit for them (link?) Any standared intercooler will work, but BIGGER is BETTER because the bigger it is, the more surface area it has. Simply get the biggest IC that you can fit.

As for name brands, remember this. A no name brand's FMIC that costs 300 dollars will only be a couple efficiency points behind a Sparco or Greddy FMIC for 1200. If you're building the turbo system to end all turbo systems, go ahead and get the brand name- but we're not building 600hp supercars. We simply don't need a IC thats THAT efficient.

Now that you've listened to my idiocy, Click here for a REALLY indepth look on Turbo Intercooler Theory @ turbocalculator.com

How to route your piping for the best gains

This is Itchy's Turbo'd 5sfe. It's piping is pretty good. The main thing to notice here is that the piping coming from the FMIC DOES NOT pass over the exhaust manifold- this is critical. What makes this setup less than perfect is that after the air is heated up by the turbo, it then passes over the intake manifold. However, it's then cooler by the FMIC, and enters the throttle body without passing by any of the exhaust. Passing over the manifold after being heated by the turbo is unlikely to add much heat; but it will still add heat, and thats something that should be avoided if possible.

This is XXX_mina's car. It's got a swapped in 3sgte engine with an FMIC. As you can see, the piping on this is far from ideal (No offense meant Mina). After the air is heated by the turbo, it goes into the FMIC. When it comes out of the FMIC it passes over the exhaust manifold, heating it back up to the temperature the air was at before it passed through the FMIC- making the FMIC nearly useless. Mina however, has done a better job here than many 3sgte's I've seen with FMICs. Note how his isn't THAT close to the manifold. Unfortunetly, due to the position of the intake manifold on the 3sgte engine, this kind of piping is hard to avoid without buying an aftermarket intake manifold.

This is uzthedentists car. Uz needs to be shot, because he has a perfect piping setup and it makes me jealous. This is perfect, see how it avoids the exhaust manifold? Uz needs to be shot, because anything he does from now on will only lesson the dream.

More info on intercooler piping and it's relationship to the exhaust manifold can be found here.

Won't my car suck because it's FWD and it's getting all this horsepower?

Yes, compared to an AWD or a RWD putting out the same whp, your car will suck. I'm sorry. Even launching doesn't compare to a RWD launch, or an AWD simply taking off from a stop. The guys at everythingcelica.com say a stock GTS can launch from a stop and own an AWD car, I'm keeping my reservations concerning that statement.

an AWD or a RWD drive swap would be best. But NO ONE has ever done this yet (compulsive liars do not count)

The thing is, AWD and RWD just put power to the wheels and the ground much more effectively than FWD ever can. After 250-300whp or so, our cars tires spin like a banshee. Thats BAD.

Can I use NAWWWZ (NOS, No2) with my turbo?

Short answer no, long answer yes with a but. The answer is that it is ALWAYS possible to add NOS to any car- F/I or NA. But, it's a bad idea to add NOS to a F/I (turbo'd or supercharged) car without REALLY beefing up the internals. Anyone who is familiar with NOS will tell you that in NOS, chemical formula one nitrogen 2 oxygen, the nitrogen is used as a carrier for the oxygen- and as the NOS gets "sprayed" into the air intake or the fuel system, it adds PSI to what the engine is getting.

That said, if you add NOS to a car running at 12 PSI, when you hit the NAWZZZZ button it might suddenly jump up to 18 psi or higher; pretty dangerous stuff.

(could someone tell me if this gain in PSI would be reported in the BOV and or boost controller? This is important, since if the boost controller detects a surge in pressure, it will adjust everything to match like it should- but then if it sends signals to the BOV, or the BOV sees it on it's own... it will just let air off.)

Why would you add NOS to a Turbo you say?

Well, smile.gif

NOS, properly done on a TC engine, can make a TC engine almost a supercharged engine if done right and computer controlled. Basically, the premise is to inject NOS early in the RPM cycle- because NOS raises the exhaust pressure, spins the turbocharger fans early and eliminates turbo lag.

Couple problems with this; the NOS needs to be a very small shot because you're inputing it lower into the RPM range. Most NOS is meant to go higher in the RPM range- this way the PSI gains are spread out. However, injecting NOS lower in the RPM range causes more NOS per revolution.

So, a smaller shot is needed; and the shot needs to cut out the instant the turbo spools to a certain point- hence it has to be computer controlled. Flip a switch into NOS enhanced race mode, and you're golden.

(Note: you'd still inject the NOS 6 inches along the pipe leading into the intake manifold)

Can I turbo my convertible? Or will it not handle the added power stress on the chassis?

American Sun Convertibles braced a lot of areas on our convertibles. Jay Greening, who saw some diagrams from ASC believes our cars should hold up to 250 hp. Currently he's putting a 3sgte engine in his car, so he will probably break in half and die a flaming death before we do- and the best news is he has next of kin, so we'll even be notified!

QUOTE (jgreening)
My BEST GUESS was that it can hold 250 whp without major structural modifications. Assuming a 20% h.p. loss through the drive train, this would be approximately 300 h.p.

Second, this was a GUESS. Do not rely on it.

There is extra bracing but most of it is rear of the lock pillar. In short, the factory (ASC) bracing is helpful but not bulletproof.

As for waiting to see if I die from the 3sgte install in the convertible before doing it yourself, that's good advice. 

Chassis Flex Post

Chassis Flex from too much power is a potential issue however, and should not be discounted just because of the bracing. I drive my car pretty rough, and am starting to get chassis flex a little. Damn.

The best bet, is to abuse the **** out of it until the chassis flex is so horrible you need a new convertible. Sell old convertible to some unsuspecting fool (who will soon be on this site), strip off engine parts, and install in new convertible. TADA!


Boost controllers, and why they are NOT optional parts in a turbo setup

Should I get my setup dynotuned after I'm done? What should I look for when shopping around for dynotuning services?

Blow off valves (BOVs)
And why they are also not optional.

A blow off valve is simply a valve that's between your intercooler and your throttle body (the intake manifold, the engine) that lets off excess pressure when you're shifting. Because the engine doesn't "suck in any air" between shifts, the intake manifold is closed- but the turbo will still pump air to it. When it reaches the closed throttle body, it has no place to go and just builds up- then rockets back towards the turbo. Because the turbo is of course, still sucking in air (in one direction) it's not a good thing when air comes BACK from the throttle body, against the direction of the fan blades. It's called compressor surge. It happens in less than a second, and it will damage your turbo like nothing else.

Of course, before that happens, pressure in that pipe between the intercooler and the throttle body builds up past your "set boost level" and your BOV (this is why they are not optional) lets off that built up pressure. So instead of your pressure soaring past YOUR set 12 psi to 24; the BOV lets off the extra air into the atmosphere; making a really cool HISS sound smile.gif

Of course, how much goes into the atmosphere depends on your BOV. Some BOVs are totally atmospheric- any air that goes into them after the pressure limit is released into the atmosphere, never to be seen again (these are the loudest).

Some however, have the ability to dump air back into the intake after the boost spike has passed (IE, right after you shift). As you can imagine, this helps with a turbo lag quite a bit.

This is actually a page of WRX BOVs, but they have a good assortment of types

Most BOVs that do both like that fall somewhere in between- there about 50% atmospheric, and 50% dump back.

A full atmospheric doesn't help with turbo lag; but a BOV that dumps back into the throttle load results inuneven acceleration. The more it dumps back in, the faster you accelerate, but it's not a smooth "happy" feeling. So, many people set their BOVs somewhere in between. If they have one that can be set that is.

A fully "plumb back" BOV is a nice item to have if you're worried about being noticed next to cops. Totally silent, because they dont release the pressure into the atmosphere.

Placing the BOV in different locations on the IC to Throttle Body pipe produces different sounds. bloodredgt @ everythingcelica.com has this to say about the palcement of the BOV:

QUOTE (bloodredgt)
well the bov being placed by the intercooler vented into atmosphere is what gives the first PFFFHT noise then mostly after that the nice deep gushing noise is the wastegate. Some run 2 keeping one open all the time. The sound when it's vented into the atmosphere actually has a higher frequency when it's lower (because the sound bounces off the asphault) and as the vehicle is passing by, a higher frequency and amplitude (undisturbed amplitude because engine noise and hot air isn't all around it) the sound of the BOV is louder and more blatent.

CAI ontop of your turbo

Can I put a CAI instead of a short ram intake?
Why, you sure can little timmy! Our own x_itchy_b_x has a CAI ontop of his turbo.

QUOTE (x_itchy_b_x)
i used the bottom half of a two peice 01 eclipse cai. for the turbo cai.

Words from a master. Of course, keep in mind that with your turbo setup, and your pipes being in different places, the bottom half of a two peice 01 eclipse CAI might not fit with your turbo setup.

Is it worth it to get a CAI instead of a short ram?
Yes it is. As we've mentioned before, how hot air is has a big determination on the psi- and the colder the air you have, the shorter the turbo lag. How do you think the air temp inside the engine bay compares with the air temp of the air whisping past the underside of the car? Colder is better, CAI is better gains than a RAM style turbo intake- but then again, it's also more dangerous.

With a CAI intake, just like on an NA engine, you have the ability to hydrolock. It's not the same however. Now, any water that wants to make it to your engine has to travel through many feet of your piping, through spinning turbo fans, through an intercooler only meant to take gases, past a BOV and finally into the intake manifold- where your car dies. Of course, instead of maybe 1-2 PSI of pressure from an NA engine, now you have upwards of 8 psi; so the force is a lot higher. It comes out to about the same risk.. All that extra pressure forces the water through more feet of intake piping and intercooler. Be careful driving over puddles, be careful in the rain, AND DONT FOLLOW BEHIND TRUCKS/SUVS THAT KICK UP WATER. If you have a variable boost controller, it might be a good idea to turn the boost way down to 4 PSI or something horrible small when it rains.

You can never take too many precautions to protect your engine and all these parts.

What about a bypass valve like on NA intakes?

It's possible to put one in, but just like on NA intakes, they decrease the gains, and UNLIKE NA intakes, you will ALWAYS be sucking air in through the bypass valve as well as the lower CAI filter, because of the sheer amount of air the turbo is sucking in. It won't prevent you from hydrolocking... At least, I dont see how it will.

What about vents in the hood- do they REALLY do anything?

For every 5 degrees you lower beneath the hood, you should gain about 1 hp

I don't know who originally said that, but he's got the idea down pat (the numbers are just estimates). The colder your engine is, the more hp it will put out. The exception of course is, when your engine isn't "warmed up" yet right after you start it.

Forced Intake engines run hotter than NA engines, because they're compressing more air, creating more power, etc. Therefore, a cool engine becomes that much more important. Vents in the hood give hot engine air a place to leave the engine bay, and new cold air places to come in. The more cold air you can trick into entering your engine bay to cool it down, the better.

Of course the more vents you have, the more bugs get into your engine bay. The more water has the possibility of getting someplace you DONT want it, etc etc.

But a vented hood is a hood investment. Personally, I don't like the look of them that much.. but because of the gains involved with cooler engines, I might be willing to make a compromise smile.gif

Some vents, like the vents on the GT4 hood, are of course made for air to get to a TMIC- but even without a TMIC they'll still cool your engine well.

I'll keep working on this through the night, what other topics should I cover?
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Lo-Fi Version Time is now: October 16th, 2019 - 1:45 PM