6G Celicas Forums

I'm going to run out of ways to say this. I'm trying to point out the distiction between flowing gasses simply pushing the turbine around, and energy (heat) being reclaimed by the turbine wheel. And while you could say that flowing gasses do indeed simply push the turbine around, I think it's worth making the distinction.

And after all this, bleading the heat from the exhaust before it reaches the turbine still hurts the performance of the turbine. Re-interpretation of my admittedly gray-area language doesn't change that.

Oh, I see. I was just trying to illustrate the difference between the way many people think a turbine works and the way it acutally does. That is, the picture many (if not most) people get in their head is that of the exhaust gasses "blowing" the turbine wheel. Hmmm, even that description can be ambiguous. Anyhow, yeah it's hard to clearly converse about. But I think we're on the same page. I hope I didn't make it more confusing than it needed to be by trying to explain myself.

If you are reffering to the part about the outlets of the turbo manifold, then it's down to heat and pressure not being completly interchangable in that part of the turbo system. However, different manifold/turbine housings have been designed to emphasize either pressure, heat, or both. Is that the part that could be considered false or am I lost here?

Haha, not quite! But if you where to dissapate heat from your pressurized exaust gasses by say... running them down the length of your car's underbody where cold air rushes by... they would remain pressurized, but not have as much of the energy to expand, dissapate, and spin the turbine as would hot gasses.

Of course, according to the Ideal Gas Law, we could be arguing semantics here, as there is a direct relation between pressure and heat. However that does not make my initial statement that turbines are driven by heat any less true. Nor does it change the fact that turbine performance would suffer if the exhausts gasses where cooled before reaching the turbine.

Altho a turbine wheel looks like a "pinwheel" or a "fan", it is a common miconception that its actually designed to work with exhaust pulses hitting the vanes. While exhaust pulses pushing the vanes soes come into play as a sort of secondary order force, turbines really are powered by heat.

Thats why if you look at the exit of a turbo manifold, the ports are pretty small. This would seem to go against the "less backpressure is better" rull for turbo cars, but that adviceonly applies to exhaust after the turbine. Forcing the fresh exhaust gasses thru a small space makes them hotter, which means they have more energy. Once the gasses enter the turbine housing, they expand into the larger spce, and dissapate heat. Again, the turbine wheel is not a "waterwheel" design. That is to say, it's not desigened to catch pulses around it's circumfrence. It's designed to harness the expansion of gasses and therefore the dissapation of heat.

I don't think it would be driveable, really. I think Formula Atlantics are like 240 hp, so the engine must be getting up arond the 11000 rpm level to spin that kind of power out of 1.6 liters. Not that that means anything in and of itself, but the profile of a 1600 making that on the track is radically different than your average -or even buil-t 7age setup. To acheive breathing at that rpm the cams, inlet valves, exhaust vales, induction system, and exhaust would be tuned way out of spec for a "normal" engine. Not to mention things that could be different like compression. Heck, those things might be set to idle at 2000 rpm for all I know. (meaning the ECU would possibly be lacking maps below that range.) Throw in the fact that the tuning most likely has no accounting for emmisions...

On the other hand, I have heard of Spoon making 1600 bseries taht can turn 11 and subsequently make 240hp and are supposedly streetable. But they have the big advantage of VTEC to work with. And Im sure they're still no peach to drive on the street.

That's rediculous. This has got to be a play by a shop that doesn't have what it takes to properly fit a turbo.

1. Turbines are spun be HEAT. That's why turbos are mated right up to manifolds. Putting the turbo way back there looks like a good way to shed alot of heat....

2. I see cold water slpashing all over an orange-hot turbine housing.... I see... small cracks appearing over time.... I see.... small cracks turning into big cracks....

I'm all for trying new things, but this really looks like a hack job to me. I've seen a write up on it in a magazine once, and I was suprised they took it seriously.

Yes, I was planning on a smallport head for this app.

The reason is that although I was intrigued by the 20v, I've seen some pretty outragous prices for cam and valvetrain upgrades compared to the 16v. Is this normal or am I shopping in the wrong places. Another thing that really burst my bubble about the 20v was seeing a dyno of a silvertop falling well short of Toyota's claimed hp. =( Still tempted to try just for the sound, tho.

Ha! Found it.

Sorry to bump such an old post, but it's got alot of good info, and Kwanza, I was wondering what your updated thought here are? As far as I know, the emanage should actually work for a MAP conversion. I could be wrong. And as far as the 7A ecu needing alot of tuning, that's actually what I WANT to do. I really want to get my hands dirty (er... digitally) and tune my own efi. My only issue is the rev limiter on the 7a ecu. I'd feel stupid paying 300 bucks just to get the rev limit moved.

I guess that's 3 main things. =)

Oh by the way, MR2 guys are all over this. Theyve come up with every which way to get 300hp. And 400...

Anyhow go look up an MR2 site. You'll get alot of great ideas.

I'm no expert, but with that kind of budget, and that kind of goal, Id look at two main things....

1- The 3sgte is already going to be out of the car. Get the thing rebuilt! There's no real gurantee on those jdm motors! I'm not sure what the weakpoint in that motor is- Im guessing either the rings or the head gasket, but I shouldn't be guessing, so dissmiss that- and upgrade it during the rebuild.

2- Have your turbo modified. Turbo's come in halves! Find out is you can just upgrade half your turbo and achieve that sort of result. Again, I'm not the guy to talk to here. Find out who is.

3- Get some fuel management and have it professionallty tuned. This is the main difference between a 300hp daily driver and a 300hp for drag runs on race gas only!

Thats all my advice. =)

Yeah, I found myself at odds with Toysport's advice. Reminded me of Mazdatrix back in the day... "No that's not feasable. Leave your car alone."

Anyhow, thank you thank you thank you for all the advice. I tried the search and I didn't quite find what I was looking for. I did, however find the conversation between yourself and Froutou when he was considering is head swap.

He was plannig to use an emanage and you recommended against it. However Im still not quite clear on why. The emanage will allow use and tuning of a map sensor on the 4a head, correct? Or is the 7A ecu too limited? Maybe I should go find that thread and read it again....

One more question... you mentioned "reworking" stock rods. Are you reffering to a standard strengthening process, like shot peening?

Thanks again for taking the time with your replay. The reason I'm not entertaining the idea of a straight swap is that I hope to one day have my own firsthand knowledge like that. I want to build and tune an engine myself. I'm tired of paying other people to do this sort of stuff. I understand the principles anyhow, I just need to DO it. I figured building a 7AGE hybrid on a stand over time would be a good place to start, since it's about the epitomy of a standard hi-po dohc. Not too pricey either. =)

I was looking at the feature lists on those pages and I have two questions.

First, neither one mentions being able to move the rev limiter. How is this tackled besides paying to mod the ecu?

And the smt6 page talks about afm setup but not MAP. It does handle MAP, correct?

I'm interested in the 7AGE setup, and there is some good info out there, but it's vague in some spots...

Specifically, about strength of the block and bottom end of the 7AFE. Most refferences to the strength of these parts is stated relative to the 4AGE. For example, the fact that the 7A block has less ribs than the 4A, or that the flywheel bolts up with less studs. Yeah, great. It's not as good as the 4A, but what does that mean? I want to know what the actual rev and boost limits are.

Reason is that altho the (7A) block, crank, rods and pistons are all stated as being weaker than the 4A counterparts, the only parts that looks really "weak" (in absolute terms) to me are the pistons. The rest looks like a pretty stout little engine. Am I correct?

So if anyone knows where I can find some info about the rev and boost limits of the 7A (or the 4A for that matter!) please help me out! First hand experience from anyone who's blown a few would be nice too. Heck, I'd even appreciate a little heresay. ;)

The clutch, the tranny, 3 diffs and 4 shafts. Im talking about an all out launch here. The parts are strong, but not indestructable, and even if they don't break immediatly, there is some accelerated wear associated with this kind of treatment. I wouldn't do it to my car! And I think many feel the same.

From my experience, the really fast launches from awd cars are produced from hi-rpm clutch dumps. And Ive heard plenty of stories about transmissions getting ruined under these conditions, although Ive never had the pleasure of seeing it in person. =) Even new evo owners are busting halfshafts here and there.

Somewhere between a baby start and a full on dump you can still get a good start, but it takes skill, and still isn't as fierce as just abusing the drivetrain.

I can think of one big disadvantage to awd taht may have affected your race. Given that teh wheels will not spin under normal conditions, something has to take the pain. Launching under full power the only choice one has is dividing the damage between the clutch and the rest of the drivetrain. So many people would not be inclined to do an ail out launch in their awd car. I know I wouldn't.

I hope your friend and his family are all safe.

AHHA! Please help me out! I've been desperatly searching for info on 5SGE and I can't find crap! I just figured the bottom end was over square and wouldn't see any gains so nobody bothered. Can you tell me where to get some info about this or contact those who have done it?

The ITR has a number od advantages.

First and formost is weight. An ITR comes in a 2600 soaking wet. Curb weights state as low as 2400 pounds. Besides having an effect on the power to weight ratio, that's lett inertia for the front tires to fight off the line.

Tires may be a factor in the launch. There where probably some nice tires on the Celi but the tires on a stock ITR are pretty impressive as far as the softness of the compound goes. Probably not that much difference here tho.

Suspension! Follow an ITR on the highway for awhile and marvel at it's rock hard ride! Many people have an easier time launching a car that is sprung and damped hard! I know I do!

Gears. A type r carries a direct 5th tranny that effectivly works like a six speed for racing purposes. Many have mentioned the ITR's lack of torque but with gears like this it doens't matter.

Ever heard the expression "Horsepower sells cars. Torque wins races."? Suprise. It's bullsh!t. With the proper gearing and a good driver, the ITR's NA 190 hp are every bit as good as a turbocharched 190 hp. A turbo in and of itself is not an advantage.


Anyhow, I can't help but say I'm shocked at some of the replies on here. Noone should be expected to know the ins and outs of every aspect of tuning and performance, but everyone should know this:

The outcome of a race will never be derived from hp and weight alone. The cars themselves are roughly one third of the race equation, the other two being the venue and the drivers. None of these three elements can be fully described on paper, let alone the synergy of all three. That's racing.

The race described in this post should be a close call, and it was. I don't know how anyone sees it any other way. Hell, I've used an e36 M3 to beat a supercharged Saleen Mustang, and yet I've somehow managed to lose to a Chevy S10 in the same car! Why? I dunno. That's racing.

Im still saving for a celica and I've decided firmly on an ST for the following reasons.

-Lighter weight. Some of this light weight is due to the ST having dinkier stock bits like brakes, bars, etc. But the most important and sizeable difference is right on the nose of the car. It's the smaller A series block. Lightweight is paramount to my project goals.

-Cheaper initial purchase and running costs. Hey, I'm cheap!

-Easier to find in low trim. Ever noticed it's alot easier to find 6gs with a solid roof and a 5 speed in ST form? No? Must be just me.

-Better engine. Ha! There, I said it! If you aren't going to do a complete swap, the 5SFE has pretty much two real options. You can bolt on a turbo, which is relativly easy, effective and a great cost effective performance boost. Or you can leave it stock and enjoy its natural torque advantages over the average four cylinder.

I think the 7A is a better engine to begin from simply because there are so many options. Mainly with head swaps from other engines in the A family. Considering this, one has the option of mixing and matching the 1.8l 7A bottom end with a series of hi performance G heads and pistons that can include superchargers, turbos, maf or map, VVT, 20v, ITB or any combination of those. Not to mention good old fashioned, inexpensive, and domestically available 16v heads with choice of factory port sizes and even TVIS , if you care for that. With more options at hand, one has a better chance of building a unique powerplant that suits their tastes.

While I would be more than happy with the power levels being produced by Turbo 5SFE engines, the delivery I see in dynos is not what I'm looking for. I wan't an engine that can develope good NA power at high rpm and sustain it for hard driving. That option just isn't available to me from a 5S. Anyhow, that's my rant.

From what I understand, swapping a 20v into an ST also involves swapping the wiring harness.

I've never worked with stand alone, so I have a dumb question here:

Could a standalone be used to operate a 20v while leaving the stock 7A wiring harness in place?

Why or why not? As detailed an explanation as possible would not be in vain, as I promise Ill soak it all up. =)

I probably should have specified but I meant adding hp and retaining a curve similar to the stock 5SFE. Which is what I estimate this setup would do.

Anyhow, how about an update!

Nah, I'm kinda "over it". For me personally, no matter how much power I have, I get used to the accellerative g force within a few hours. Nowadays, as long as the power is adequate, I'm pleased. It's just that in the Celica, 130hp is not quite... adequate. =)

A turbo compressor that flows efficiently at 5-6 psi is going to produce a cooler charge than a positive displacement blower at the same pressure, which by the way are almost never intercooled. At that low of a pressure, plumbing in an ic would not be worth it, considering that the turbo would have to huff harder to make up for pressure drop going thru piping and the core itself- producing a hotter charge coming off the cold side. Throw in cost while you're at it but the real issue here is throttle response. all things equal, an engine that has better throttle response allows the driver to deliver more of the total available power, more of the time.

By the way, playr one-five-six, I am in fact retarded. Can't you tell? Try to be a little more sensitive.

It would be a huge help to see these dyno'd before and after. I think you would sell alot more if there was some sort of data. Maybe you twou could split the cost of two pulls of something?