how much boost can i run on my 3sgte

[stevo 27]

how much boost can i push before i gotta get rid of the stock injectors on a 3sgte?
any help would be appreciated

[bmeier]

15 psi is considered "max" you might hit fuel cut before that though.

[stevo 27]

so im technecally good until 15
so 12 should be fine then?

[alloroc]

http://www.jekylhyderacing.com/

http://www.jekylhyderacing.com/storymission.htm

If you can't find enough clues on his web Email Jeff he's a real nice guy and may be able to point you in the right direction.

[CelicaST-162]

10-12 is fine, as long as your car is fine. No leaks, not burning oil, fix any engine problems if theres any, then you're good to go.

[stevo 27]

thanks glad to know yea everythins pretty much new in\on the motor

[hellraiser456]

15 psi???

im pretty sure my buddies mr2 is bone stock except for a boost controller and plug and exhaust and intake...and he runs the ct 26 until it near craps itself...at high boost he is up at like 20 psi..now the ct-26 anything over 14 basically is simply useless...

mind you that said..it is possible he has a upgraded fuel system in it but i can't confirm or deny that as he doesn't really know what has been done to the car other than the obvious stuff like exhaust and intake.

that said a cheap injector upgrade i hear going around for the 3s group is use supra injectors...you can find the for really cheap as supra guys usually upgrade them the moment they hit fuel cut or get a lex afm. as to which ones from what engine i don't know..if i had to guess i would say the 7m...but don't take my word on that.

if you know where to look you can probably find them for 20-40 bucks for all four

[bmeier]

above 15 psi is considered to be unsafe, plus the ct26 can barely hold 15 psi after 5500 rpms...

Also adding larger injectors wont do you any good, the stock fuel system is more than capable upto 275 rwhp

read this very good writeup on 3sgte performance
http://www.mrcontrols.com/primers/power.htm

[bmeier]

stevo 12 is fine although you still might hit fuel cut, there is a simple fix to that problem though its in the primer i just posted above

[stevo 27]

now he said stock boost pressure is 10-11
why am i only running 5-6?:dunno:
i thought it was stock
is the 3sgte in the mr2 diffrent in some way to the alltrac 3sgte?

[New2Talon]

Im assuming your talking about a 2nd gen 3's?

7-8 is the stock boost pressure, with the ct26 and internal wastegate. If the wg spring was changed out then you could have a higher psi w/o using a boost controller. If your not reaching 7-8 and you are running stock then you have a leak somewhere. check vanuum lines and wg.

There are a few mounting differences, but the engines themselves are the same. 93 mr2 have a different intake manifold. Im not sure if the alltrac is the same and for what year.

[bmeier]

you should be running 7 - 8 psi stock. on hot days though if your intercooler is heat soaked you could see 10... this would be in 3rd or 4th gear though near redline. in fact i am willing to bet you hit 7-8 you have to do a pull in 3rd or 4th gear to hit max boost though...

[stevo 27]

i redlined through all the gear regularly till my turbo seals went
and never saw over 6 psi but could the seals have had somethin to do with that?
:banghead:

[Annoyingrob]

Originally posted by stevo 27
i redlined through all the gear regularly till my turbo seals went
and never saw over 6 psi but could the seals have had somethin to do with that?
:banghead:
If the center housing is coked with oil then yes, it can cause issues like that. I've seen turbos with bad seals where the shaft could barely turn.

....However, it's unlikely. I would take off the intake pipe into the turbo, and spin the turbine. If it spins freely, then that's definitely not your problem.

How does the car run? Does it sputter a little at idle? Does it shoot black smoke out at any time? These would be symptoms of an intake leak.

[New2Talon]

Originally posted by Annoyingrob

...how does the car run? Does it sputter a little at idle? Does it shoot black smoke out at any time? These would be symptoms of an intake leak.

symptoms could also be from running pig rich...

[stevo 27]

no spins freely no shaft play what so ever burns alot of oil never seen i blow black smoke before the turbo went it ran like a champ
:dunno:
i guess now that i have it all apart im gonna check for leaks every were
im gonna replace all the basics :dunno:

[bmeier]

your boost gauge might also not be very accurate... if everything runs fine after you replace the turbo i wouldn't worry about it.

[Annoyingrob]

Originally posted by New2Talon


symptoms could also be from running pig rich...
Yes, a leak after your AFM will cause it to run rich under boost, which is why I asked :)

[stevo 27]

just curious what power gains could i see
i have the opertunity to make myself a 3" dp and full exhaust for
preacticly nothin
and will it run fine if i toss the cat?

[91tomstwo]

Everyone says it's not recommended past 15 psi....blah...blah...blah

It all depends on the turbo. (i.e. CFM the the turbo is able to flow at X psi)

Slap a wide band on the thing and turn up until you hit high 11 A/F Ratios.

I'm currently running 16 psi on a Precision SC50 and made 320 WHP last year with no issues what so ever. Is it recommended? probably not, but is turning up the boost on a factory turbo recommened? probably not.

If you want more power, upgrade your fuel system.

It comes down to what YOU think is safe. I think anything under 12:1 AFR is safe. You are you're own judge.

[bmeier]

Stevo a downpipe will make the turbo spool a lot faster and you will also gain a decent amount of power.

91 tomstwo - this whole thread is about the limits of the stock turbo and fuel system, obviously you can go above 15 psi if you change the fuel system etc. he wants to know whats safe with a stock system . also you claim to have 320 rwhp , is this on a stock fuel system? do you have any dyno charts?

[naheed187]

i ran 20psi on my sr20det before doing injectors and ecu.. and i blew my turbo everything it would spool up it would make a loud noise.. then i upgraded to the hks 2530, 550cc injectors and hks f-con pro

[bmeier]

what the hell does that have to do with anything we are discussing?

[stevo 27]

so full 3" exhaust it ll spool quicker
and get some decent numbers sweet gonna get to doin it

and one more question if i run straight pipe no back pressure wont really matter would it?

[bmeier]

nope turbos want to be as free flowing as possible

[New2Talon]

Originally posted by Annoyingrob

Yes, a leak after your AFM will cause it to run rich under boost, which is why I asked :)

There could be other things besides a leak in the intake that could cause him to run rich...If he was rich he should find out why.


Also if his booost gauge is off, he should still be able to tell 5-6psi on the butt dyno...if you crank it up it should go faster, regardless of what the gause says.


With a full 3" you COULD potentially run into problems with creep (not saying you will, but it is more possible)

[91tomstwo]

91 tomstwo - this whole thread is about the limits of the stock turbo and fuel system, obviously you can go above 15 psi if you change the fuel system etc. he wants to know whats safe with a stock system . also you claim to have 320 rwhp , is this on a stock fuel system? do you have any dyno charts? [/B]

Obviously you didn't read my post at all.

1 I said it depends on the turbo to determine max boost levels before you run out of fuel.

2. If i am running a bigger turbo and still able to push 16 psi, what makes you think the baby stock turbo is going to cause the MR2 to run out of fuel at 15 psi?

3. Last but not least, strap a wideband on and you leave the guessing game out of the equation.

and yes, I am running on stock fuel system however, I am upgrading to top feed fuel rail this year. I bought the Extremeboost TFFR.

cheers y'all

-kl

[bmeier]

interesting i would love to see a Dyno sheet if you do have one.

[91tomstwo]

My dyno is posted in this thread.

cheers!

-kl

http://forums.beyond.ca/st/169149/best-1-4-mile-time-mr2-only/

[bmeier]

do you have one with the AFRs?

[91tomstwo]

Nope, logged it separately on my laptop and wideband when tunning on the street. I never went into the 12's thought for A/F ratio.

[stevo 27]

would i still possibly run into boost creep with my MBC
and instead of going full 3 inch with no muffler im think of runnin
a3" dump out behing the passanger front tire with no muffler
cause i figure it would be pretty loud so i wanna be able to switch
from ear peircing and normal
would work the same though would it not?

and i have a A\F gauge in my pillar whats the difference between
that and a wideband?

[Annoyingrob]

Originally posted by stevo 27
and i have a A\F gauge in my pillar whats the difference between
that and a wideband?
A wideband actually means something :)



A stock narrowband sensor will only show you lean or rich, it's like a switch. A Wideband and display will give you an actual decimal A/F readout, like 12.73:1

[stevo 27]

good to know so i guess the only way i can really find out if
i have the right a\f is bring it to the dyno

[Milk2%]

well if thats a 88 alltrac without a swap, you have a 1st gen 3sgte. i wouldnt take it above 12psi. 2nd gens been known to run safely at 14-15. and as high as 19-20 with water injection. pick up an innovation kit to monitor your a/f. All 3sgtes tend to run dog rich. get 3'' all the way to the back, you will love it.

[stevo 27]

nope its a jdm st 185 3sgte in it

[Redlyne_mr2]

the ct26 is whats holding you back...swap that and youll have some power

[stevo 27]

thats whats next but i just wanna get it on the road for now in a month or so im gonna pick this turbo up would this match the motor?
and buy some cams to i want more high end power

turbo
http://www.blaastperformance.com/index.php?p=t3t04e-60
dur lift
Intake 3SGTE 272 9.2

Exhaust 3SGTE 272 9.15

hopeing that would do me good

i was thinkin of buyin a mega squirt at some point
but im goin by paycheck to paycheck
and learning as i go

[celicaguy]

mmm well for starters come check out alltrac.net if you havnt already. All the answers are there. btw stock boost on the jdm motor (if you ahve the ecu as well) is 9psi, and i think the fuel cut is a little higher than usdm. With that said, there have been very very few 500+ hp alltracs made, but there are a few guys on alltrac.net that are there. come check it out

[New2Talon]

if you have a stock jdm 185 swap then you dont have w2a ic. you would have the topmount a2a ic. w2a is on the st205 and 185 rc engines.

jdm also has better turbo, and if you can take advantage of it, a better ecu, but you probably wont notice a difference in the ecu. teh jdm runs more advanced timing, but requires higher octane. low octane (91) will probably mean the ecu will retard the timing so it will be comparable with the usdm ecus.

[zain123]

am glad the car is treatin u good :)

theres turbo upgrade kits offered on sponsor sites on alltrac.net or celicatech.net for this car so make sure u check them out

goodluck with the project
oh and its exeddy clutch (not stage 2)

[stevo 27]

yea since it sat so long the turbo was fubared but i fing love the car so fun when its going

[stevo 27]

Originally posted by New2Talon
if you have a stock jdm 185 swap then you dont have w2a ic. you would have the topmount a2a ic. w2a is on the st205 and 185 rc engines.

jdm also has better turbo, and if you can take advantage of it, a better ecu, but you probably wont notice a difference in the ecu. teh jdm runs more advanced timing, but requires higher octane. low octane (91) will probably mean the ecu will retard the timing so it will be comparable with the usdm ecus.


well the ceramic turbo fried so im buyin a usdm ct 26 just to get it back on the road until i upgrade

[zain123]

just upgrade now.. dont downgrade :p

[Redlyne_mr2]

A ct20b should fit on there...I think there are a few for sale here locally..that will get you to 300whp...maybe post a wtb thread in the mr2 section if thats what youre after since the turbo you posted will require an adapter for the manifold as well as a wastergate.

[stevo 27]

i wanna upgrade but i already bought the usdm ct26
just to get it on the road and i already asked around for a ct 20b
and jdm source said about 2000 for it i could get the waste gate
and mani for that with the turbo so yea haha
but no this summer doin the works hopefully see how much mula
i can blow pistions ,head work, cams ,intake, exhaust mani
full 3" (already have all the piping) new valve train
see how far i can go :burnout: :burnout: :burnout:

[Milk2%]

272's are going to be way over kill

[stevo 27]

over kill is good :D

[Milk2%]

stagger your cams 272 - 264 , is this going to be a DD? i would go with like 264-256. read up at www.mr2oc.com you will learn everything you need to know about 3sgtes. Some very very smart people in there

[stevo 27]

thanks man

[stevo 27]

ok got the new turbo to get it runnin
but its runnin stupid rich feels like MAF again
and does anyone know if the usdm MAF work
on the jdm motor?

[New2Talon]

IIRC the usdm and jdm afm are the same

[stevo 27]

sweetness never know

[jekylandhyde]

Originally posted by stevo 27
how much boost can i push before i gotta get rid of the stock injectors on a 3sgte?

If you are running the stock CT26, you will not out run the stock injectors with that turbo. You will have other problems long before then :)

The CT26 is only efficient up to 15 psi, which you will have plenty of fuel to run.


Originally posted by New2Talon
Im assuming your talking about a 2nd gen 3's?
7-8 is the stock boost pressure,
Hey New2Talon, that is incorrect. The Gen2 3SGTE runs 11.8 psi stock. Under certain circumstances (too cold outside, coolant not up to temp, knocke/detonation) the ECU will open the T-VSV and limit you to 7-9 psi until the circumstances change.

If everything is healthy and running correctly, a Gen 2 3SGTE should easily see 11 psi.


Originally posted by bmeier
you should be running 7 - 8 psi stock. on hot days though if your intercooler is heat soaked you could see 10...
Again, stock boost is 11.8 psi and will be limited to 7-9 if something is off.

When your IC heat soaks, you are not likely to make more boost.
You are more likely to have knock/detonation which will result in the the ECU pulling timing/adding fuel/limit boost ... all which will lower your boost pressure.


Originally posted by bmeier
this whole thread is about the limits of the stock turbo and fuel system, obviously you can go above 15 psi if you change the fuel system etc. [/B]

Changing the fuel system is not going to change the efficiency of the CT26. You are safer running 15 psi out of a bigger turbo with stock fuel than you are running the CT26 @ 18 psi with upgraded fuel.


Hope this helps ... good luck with your project!

[stevo 27]

hey^^^^ you seem to know your shit i have never seen over
7-8 psi outta mine

[jekylandhyde]

Check out the first block here (7.1 - 11.8 psi):

http://www.mr2-tech.com/bgb/mechanical/volume1/turbocharger_system/Manual_0264_0001.jpg


As for your issue with not being able to rev over 4000 rpms,
do you have catalytic covnverters installed on your car?
If so, I suspect they are clogged up ... which will also reduce your ability to make boost.

Both of your problems might be the same thing.

[Redlyne_mr2]

haha what are you doing in our little forum here Jeff

[stevo 27]

i gutted the cats and im reading 7 psi

[stevo 27]

IT WAS THE MAF IT PURRS NOW YAYYYYYYYYYYYYYYYYYYYYYY!!!!!! :clap:

[New2Talon]

Where did you get a replacement from?

[stevo 27]

chris guy with a sickkk!!! gt four

and my car is running lean i dunno what it could be???