how many lbs of boost Options

[Kerr1]

how many lbs of boost can a stock 5s head handle....im not worried abt. the internals just the actual head.

[lagos]

c. this question is impossible to answer

[Gary]

200 psi
Seriously, You might outflow the F head but it is not gonna blow because of boost.
Head gasket is another story.

[Kerr1]

i thought u could crack the head w/ too much boost so i wasnt sure if ne1 has ever done it b4...do yall know how much stock pistons can handle...

[x_itchy_b_x]

to many unkown factors to answer that question accurately.
psi is a very vague measurement of how much pressure the engine isn't ingesting. and not to much is known about the limits of the 5fste except it can handle a good beating.

[NuclearHappineS]

why do you ask ?

how much power do you want to make ?

the more the boost the more the bottom end will hate you ... the head will be fine ... the "head" is more affected by raising rpm limits than it is by having boost in it...

the thing is say you want to make 300hp out of a 5sfe... it will take ALOT of boost on the stock head.... if you cam it , or oversize the valves, or port it properly it will take less psi to make the same hp figure... that's really how the head comes into the equation...

[Kerr1]

o...well do u think stock pistons can handle 15psi? not daily but i dont want to build a motor w/ stock pistons thinkin it can hanle the power and not...thats all i was wonderin....basically wat do i need for 15 safely? maybe thats a better way of putting it.

[lagos]

wat do i need for 15 safely? maybe thats a better way of putting it.

on what turbo? 15psi on a ct26 like i have, and 15psi on the holset that itchy has are two very different things.

the problem with running high boost on a 5sfe is not with the strength of the pistons or the head. its with the fact that its a high compression motor. the higher the compression, the more chance you have to run into detonation when trying to turn up the boost on pump gas. detonation is what ends up killing pistons, rods, headgasket, etc...

[king_wsk]

wat do i need for 15 safely? maybe thats a better way of putting it.

on what turbo? 15psi on a ct26 like i have, and 15psi on the holset that itchy has are two very different things.

the problem with running high boost on a 5sfe is not with the strength of the pistons or the head. its with the fact that its a high compression motor. the higher the compression, the more chance you have to run into detonation when trying to turn up the boost on pump gas. detonation is what ends up killing pistons, rods, headgasket, etc...

Would water/alcohol injection resolve this? I've been reading up on the devil's own kit and am seriously considering it being that I already run 15 degrees timing and I'd like to run more but I get pinging from 91 octane, but If I went with DO's W/A I. the effective octane would be 110+....

[Kerr1]

so low compression pistons wouldnt b a bad way to start? Im trying to find a ct26 now...is there a diff. between the mr2 one and the supra one? cuz i think i might b able to buy the supra one for like 50 bucks practically new.?

[x_itchy_b_x]

Low compression would be a good start if you wanted to build the engine.
since your talking about dropping some money into the 5sfe id recommend just swapping in a 3sgte and put the money into that.
the potential of the 5sfe isnt as great as the 3sgte, depending on how far you want to take it.

The supra ct26 has a different downpipe flange to it, you would have to custom make a downpipe to use it. also it flows a hair more on the exhaust side than the mr2 ct26, its also single entry where the mr2 ct26 is twin entry. The easiest route is to use the celica/mr2 ct26.

[lagos]

wat do i need for 15 safely? maybe thats a better way of putting it.

on what turbo? 15psi on a ct26 like i have, and 15psi on the holset that itchy has are two very different things.

the problem with running high boost on a 5sfe is not with the strength of the pistons or the head. its with the fact that its a high compression motor. the higher the compression, the more chance you have to run into detonation when trying to turn up the boost on pump gas. detonation is what ends up killing pistons, rods, headgasket, etc...

Would water/alcohol injection resolve this? I've been reading up on the devil's own kit and am seriously considering it being that I already run 15 degrees timing and I'd like to run more but I get pinging from 91 octane, but If I went with DO's W/A I. the effective octane would be 110+....

it wouldnt totally resolve it, but it sure would help a lot. for you, since your NA, using WI is going to be tricky, because its a system that is normally triggered by boost.

[lagos]

so low compression pistons wouldnt b a bad way to start? Im trying to find a ct26 now...is there a diff. between the mr2 one and the supra one? cuz i think i might b able to buy the supra one for like 50 bucks practically new.?

if your going to drop the compression on the 5sfe, you might as well just go with a 3sgte swap. youll get a low compression motor, with a turbo, injectors, and ecu that can handle 15psi on a ct26, just fine. it would probably cost you the same as your motor build up, and the sky is the limit if you want to make more power down the road.

[x_itchy_b_x]

for WI on an NA im pretty sure they use an rpm & wot trigger just like nitrous.

[cjh4l22]

wat do i need for 15 safely? maybe thats a better way of putting it.

on what turbo? 15psi on a ct26 like i have, and 15psi on the holset that itchy has are two very different things.

the problem with running high boost on a 5sfe is not with the strength of the pistons or the head. its with the fact that its a high compression motor. the higher the compression, the more chance you have to run into detonation when trying to turn up the boost on pump gas. detonation is what ends up killing pistons, rods, headgasket, etc...

Would water/alcohol injection resolve this? I've been reading up on the devil's own kit and am seriously considering it being that I already run 15 degrees timing and I'd like to run more but I get pinging from 91 octane, but If I went with DO's W/A I. the effective octane would be 110+....

91 octane? y don't you run 93?

[lagos]

cali only gets 91. still, if your pinging on 91, then its probably a good idea to back off the timing.

[Kerr1]

for the 3sgte swap its like 4000 and thats if u do the wrk urself....im not plannin on spendin that much...in the end ill prolly have put at the most 1/2 that. and have the same or more power....but it would only b 2 wheel drive.

[lagos]

for the 3sgte swap its like 4000 and thats if u do the wrk urself....im not plannin on spendin that much...in the end ill prolly have put at the most 1/2 that. and have the same or more power....but it would only b 2 wheel drive.

its going to cost you more then 2grand to rebuild the motor, lower the compression, turbo it, and tune it.

[Kerr1]

for the 3sgte swap its like 4000 and thats if u do the wrk urself....im not plannin on spendin that much...in the end ill prolly have put at the most 1/2 that. and have the same or more power....but it would only b 2 wheel drive.

its going to cost you more then 2grand to rebuild the motor, lower the compression, turbo it, and tune it.

idk...im gettin a lot of parts REALLY Cheap....yea...itll prolly cost a lil more but still not 4g's and by the time im done itll put down more power than the 3s...at a lower price...the only thing im "iffy" abt. is i kinda want the all wheel drive but....i still want the 5s motor tho....sooooo

[lagos]

you do realize that most 3s swaps are not awd, right?
what turbo are you planning to use?

[presure2]

for the 3sgte swap its like 4000 and thats if u do the wrk urself....im not plannin on spendin that much...in the end ill prolly have put at the most 1/2 that. and have the same or more power....but it would only b 2 wheel drive.

without some SERIOUS headwork, you WILL NOT make more power than the 3s.
trust me, i know.
you should think about a power level you would like to acheive, then use as little boost as you can to get there.

[Kerr1]

yea...i know....but if i did it thats how it would b....b/c thats the way they r supposed to b. Prolly ct26 from a 7mgte supra. a downpipe wont b hard to make at all....and i got a friend who can make an adaptor from the manifold to the turbo.

[Kerr1]

for the 3sgte swap its like 4000 and thats if u do the wrk urself....im not plannin on spendin that much...in the end ill prolly have put at the most 1/2 that. and have the same or more power....but it would only b 2 wheel drive.

without some SERIOUS headwork, you WILL NOT make more power than the 3s.
trust me, i know.
you should think about a power level you would like to acheive, then use as little boost as you can to get there.

U dont think w/ mr2t pistons i can make more power than a 3s? same internals but it would b on a 2.2...idk....mayb im just wastin my time and money...but right now its all i got....and i just think it would b somethin diff. to build a 5s instead of just doin a swap. (just a matter of pesonal opinion for me) when i get done in a couple of months....plannin on christmas as my "deadline" ill let u know how its goin.

[quantumspec1]

I'm going to have to agree with just snagging a 3SGTE, if you just watch a few of the importers they will run specials. A few months ago you could snag a caldina ST215 motor/ecu/wiring harness with AWD tranny for 1800 plus shipping. I got my ST185 with 34k miles for 1800 shipped. Your best bet is to wait for a deal if your motor isn't already shot. But, your money.

-Dustin

[lagos]

whats your horsepower goal for the car?

[presure2]

for the 3sgte swap its like 4000 and thats if u do the wrk urself....im not plannin on spendin that much...in the end ill prolly have put at the most 1/2 that. and have the same or more power....but it would only b 2 wheel drive.

without some SERIOUS headwork, you WILL NOT make more power than the 3s.
trust me, i know.
you should think about a power level you would like to acheive, then use as little boost as you can to get there.

U dont think w/ mr2t pistons i can make more power than a 3s? same internals but it would b on a 2.2...idk....mayb im just wastin my time and money...but right now its all i got....and i just think it would b somethin diff. to build a 5s instead of just doin a swap. (just a matter of pesonal opinion for me) when i get done in a couple of months....plannin on christmas as my "deadline" ill let u know how its goin.

"mr2 pistons" wont help you make more power.
they wont fit.
like i said, if your looking to make over 300whp on a 5s, 5-6k is a "cheap" estimate.
just to get the head to flow close to what the 3s does, your looking at 2k+ in headwork, + cams.
then, a built bottom end.
then EMS,
then tuning.
thats not even talking about building a turbo kit thats capable of makeing 300whp.

[lagos]

troof ^

[NuclearHappineS]

the stock compression ratio will limit you to 8-12psi depending on weather the turbo is on the bigger side of things or the smaller side of things ... (the bigger the turbo the higher you'll be able to boost before you run out of octane and detonate).

so now you say you'll just drop the CR... sure, it will cost you 400 for JE or SRP custom 5sfe pistons... so now you can run 15psi possibly but you are limited to 240hp @15psi @ 5200rpms no matter what turbo you use (the head just wont be able to outflow that much... )

if your goal is 300hp on a stock head with the lowered CR it will take about 20psi to do it by my math...

a head that flows 19% more (like a 3sgte head) can do 300hp @ 15psi @ 6200 rpms

as for the water injection for the normally aspirated car... more timing isn't always more power... you already obviously have too much timing in it... if you add WI and you add even more timing you will lose your rod bearings from the added timing...

See at idle your oil pressure is low because hte rpm's are low... too much timing advance will mean that power is delivered and pounded down on your pistons/rods earlier than it should be (which is how you end up with detonation) ...

adding base timing is not the same as adding timing up top via an EMS or adding boost at higher rpms with the help of water injection...as when the rpms are up, the oil pressure is higher so there's less possibility for bearing failure...

... i wrote too much

[Kerr1]

im plannin on doin head wrk to the new 1 im buying....that i get done for FREE....my uncle has all the tools for it.

[Kerr1]

the mr2t pistons wont fit if i bore it .020? i think thats how much bigger they r....but i havent researched the height yet....ne1 know?

[lagos]

im plannin on doin head wrk to the new 1 im buying....that i get done for FREE....my uncle has all the tools for it.

sorry bud, but you need to do some more research.

[NuclearHappineS]

the 5sfe is the overbored version of the S block...so if you use 3sgte pistons you will have a 0.020" Gap ... that and the 5sfe head is different so the compression and squish will not be ideal...

[blckcelica95]

Kerr1 i did the exact same thing that you are planning on doing except i had custom pistons made for my block. yes building your own motor is fun and not many people have built a stonger 5sfte but in all honesty a 3sgte swap is the way i would go now if i could. the horsepower to spending ratio sucks

[presure2]

Kerr1 i did the exact same thing that you are planning on doing except i had custom pistons made for my block. yes building your own motor is fun and not many people have built a stonger 5sfte but in all honesty a 3sgte swap is the way i would go now if i could. the horsepower to spending ratio sucks

thanks for chiming in. good to hear it from someone that has done it.
i couldnt agree more.
and thats coming from a guy who LOVES his 5sfte.
if your goals are ~250 or so whp, the 5sfte can do that in spades, with TONS of torque, if you build it right, and thats in stock longblock form.
once you start trying to modify the engine at all, the 3sgte is just a better choice, plain and simple.
as far as you doing the work yourself on the head, its not that easy...you dont just go in and start removing material, thinking its gonna work, cause it wont.

[Kerr1]

Kerr1 i did the exact same thing that you are planning on doing except i had custom pistons made for my block. yes building your own motor is fun and not many people have built a stonger 5sfte but in all honesty a 3sgte swap is the way i would go now if i could. the horsepower to spending ratio sucks

thanks for chiming in. good to hear it from someone that has done it.
i couldnt agree more.
and thats coming from a guy who LOVES his 5sfte.
if your goals are ~250 or so whp, the 5sfte can do that in spades, with TONS of torque, if you build it right, and thats in stock longblock form.
once you start trying to modify the engine at all, the 3sgte is just a better choice, plain and simple.
as far as you doing the work yourself on the head, its not that easy...you dont just go in and start removing material, thinking its gonna work, cause it wont.

O i know that.....but my uncle has been doin this kinda stuff his entire life...he builds engines for a living....and he's 60...he knows wat hes doin and we r gonna do all the research....plus....i would actually b happy w/ 250whp b/c i would have some crazy torque lol...my car doesnt need a whole lot to keep up w/ most of the ppl around here....lol...theres a 210 whp 240 that smokes pretty much a lot of ppl around... and dont get me wrong i understand where yall r sayin just do the swap...but then to me its no fun...its bought already fast stock....i mean theres plenty of things i could just buy fast....i just want to b able to say i built the motor thats in my car from ground up. Thats all im sayin.

[Gary]

O i know that.....but my uncle has been doin this kinda stuff his entire life...he builds engines for a living....and he's 60...he knows wat hes doin and we r gonna do all the research....plus....i would actually b happy w/ 250whp b/c i would have some crazy torque lol...my car doesnt need a whole lot to keep up w/ most of the ppl around here....lol...theres a 210 whp 240 that smokes pretty much a lot of ppl around... and dont get me wrong i understand where yall r sayin just do the swap...but then to me its no fun...its bought already fast stock....i mean theres plenty of things i could just buy fast....i just want to b able to say i built the motor thats in my car from ground up. Thats all im sayin.

Then ditch the F head do the 5SGTE or stroked 3SGTE.
That's what I call fun.

[Kerr1]

yea...i guess that would b pretty kewl...i think i might do that its only like 30 more dollars for the 3s head.

This post has been edited by Kerr1: Aug 4, 2007 - 1:24 PM

[lagos]

yea...i guess that would b pretty kewl...i think i might do that its only like 30 more dollars for the 3s head.

[NuclearHappineS]

My take on things...

Build the following :

5sfe head + oversized valves + cleaned up combustion chamber (slightly lower compression ratio) + cleaned up head ports , especially the exhaust side) ... your uncle can probably do this easy.

98+ camry metal head gasket + new head studs (even if OEM)

Stock bottom end

2jzgte cam gear machined to fit the 5sfe camshaft end

3sgte gen 1 exhaust manifold
Upgraded T04 based CT26 or equivalent turbo
3" Downpipe to a 3" exhaust

MAP-ECU2
RX7 440cc Injectors
No need for a 2bar map since the MAP ecu has a built in map sensor...

Clutch (with 280ft-lbs holding capacity), stock flywheel is fine

3sgte oil pan or tapped 5sfe oil pan

NO MBC (just get a turbo with a wastegate set around 10-12psi)
1 step colder iridium or copper plugs

EGT gauge
Wideband O2
Boost Gauge
Oil Pressure Gauge

Colder thermostat (170*)
Intake manifold gasket...

And that's it

go price that ... probably 5000 usd ... but that's how i'd build it... should make 250 crank @ 12psi ... with the ability to tune fuel, ignition timing, and cam timing and at least 25cfm of added head flow from the oversized valves (Even if you don't do any other head work with it)...

[NuclearHappineS]

I guess what I'm trying to say... imho the most important part is tunability

so if you want to bring it down to the core... for me ... it's the cam gear + the map ecu2 + the colder plugs ...

around that if you want to save cash go with a 3sgte manifold, CT26 based upgraded turbo (but not a stock CT26 they are crap, at least get a CT20B), 3sgte dp ...etc

you can skip the gauges , but definately get it put on a dyno for tuning...
you can skip the MBC ... i don't think the 5sfte is a type of car you'd want to overboost, underboost...etc it just doesn't have the bottom end for you to want to switch between 10psi and 25psi ... so just set it at the right boost (the one you dyno tuned at) and forget it ...

that kind of stuff...

Tuning is key...

The oversized valves are worth 1.7psi
A ported throttle body is worth 1.0 psi
Cams are worth 2.0psi roughly

so having all those and being at 12psi is like a stock 5sfe running at 16.7psi ... see what i'm saying ...

[Kerr1]

yea...but im not spendin that much...lol....this is my plan...mayb 3sgte head....2 throttle bodies.....forged 8-1 wisco pistons...balanced crank.. ported intake and exhaust sides of the head....ported intake manifold...then turbo kit. if i dont get the 300 hp....thats fine...its still a trq beast.lol

[NuclearHappineS]

Some portwork numbers to give you an idea... this is from an E55 mercedes head with stock cams...

Intake , 2 X 38mm valves
Peak flow 261 CFM
Average flow 201 CFM

Intake, 2 X 39mm valves + Race port
Peak flow 304 CFM (Increase of 16.4%)
Average flow 219 CFM (Increase of 8.9%)

Exhaust, 1 X 43mm valve
Peak flow 167 CFM
Average flow 123 CFM

Exhaust, 1 X 43.5mm valve + Race port
Peak flow 212 CFM (Increase of 26%)
Average flow 141 CFM (Increase of 14%)

To give you an idea, each 1.455 CFM is about 1 HP...

Most people don't see this kind of data for Toyotas so i thought i'd share...

-Nuke

[Kerr1]

sweet info....thanx a lot nuke.

This post has been edited by Kerr1: Aug 5, 2007 - 12:27 PM