3sGE unboostable?, Dont burst my little bubble... please! Options

[markjbutler]

Hey all,

not been here long and reading around the very few posts about boosting the 3sge it seems that it either a) isnt a good idea or b) just simply shouldnt be done. I've read up on wiki about how turbo systems work and also looked at the differences between both the T and non-T versions of the 3S and bar a few parts in the bottom end and compression ratio there aren't any discrepencies - correct?

so... with a standard compression ratio would it not be possible to boost the 3s just at low PSI? As far as i understand it the whole point of boosting is to force more air+fuel into the chamber i.e. artificially raise the compression ratio to rather giddy heights so therefore starting at a higher ratio could be seen as a benefit as you could use lower pressures/smaller turbo i.e. faster spool up times (i'm yet to get into what the hell A/R and all that palava is).

I may be way off here - dont be too rude on this n00b!

p.s. going to refurb my alloys tomorrow hopefully, black wheels on a silver celica acceptable? i'm thinking black should be the hardest colour to get wrong (although they cant look any worse than they do now)

Cheers if you are still reading!!

This post has been edited by markjbutler: Mar 7, 2008 - 4:34 PM

[DEATH]

It can def be done. You would follow the same principles as the 5S-FTE guys.
Do what you want - It's your car. And you know what to say to the naysayers

[97lestyousay]

I am not sure which one you are talking about. I am no expert but if I remember correctly
the beams and other na 3sges are higher compression which makes using stock internals
risky.

[lagos]

The 3sge and 3sgte are very different motors. You can still turbo your 3sge the same way you would boost a 5sfe.

[DEATH]

Oh snap - I forgot to mention the BEAMS thing. Thanks 97lestyesay for covering my mistake. I have owned a few USDM 3S-GE's and I'd say they are every bit as boostable as 5S - just same rules apply and I wouldn't run more than 5PSI due to the CR.
Edit: Oh yeah - I forgot to mention that the USDM ones are limited to 1st gen 3S IIRC. Whatever - just read the multitude of info on the 5S-FTE and add a little safety cushion in for breaking somewhat new ground.

This post has been edited by DEATH: Mar 7, 2008 - 7:16 PM

[markjbutler]

I am not sure which one you are talking about. I am no expert but if I remember correctly
the beams and other na 3sges are higher compression which makes using stock internals
risky.

that was the impression i got from a few of the posts i read here... i cant remember who but there was a member here who seemed to know what he was doing and even he was dissuaded from going the 3sge + T route by some other members. Alan or something rings a bell - its late now and i've been in the garage with paint stripper!!

edit: the whole car cost me £1500 so i'm not going to cry (too much) if it explodes

The 3sge and 3sgte are very different motors. You can still turbo your 3sge the same way you would boost a 5sfe.

thats news to me - i was under the impression that for the most part they were essentially the same motor - o well, learn something new everyday i suppose.

Oh snap - I forgot to mention the BEAMS thing. Thanks 97lestyesay for covering my mistake. I have owned a few USDM 3S-GE's and I'd say they are every bit as boostable as 5S - just same rules apply and I wouldn't run more than 5PSI due to the CR.
Edit: Oh yeah - I forgot to mention that the USDM ones are limited to 1st gen 3S IIRC. Whatever - just read the multitude of info on the 5S-FTE and add a little safety cushion in for breaking somewhat new ground.

Are the USDM 3s' the same as the ones here in the UK? I thought you lot got neutured ones because of emissions or something? Or is that what you mean by being limited to 1st gen? I take it mines a 3rd gen being a '97? I've been reading pretty much everything on here regarding booOOOst anyway so thats fine!!

thanks all!!

This post has been edited by markjbutler: Mar 7, 2008 - 7:46 PM

[97lestyousay]

The us 3sge is 9.2 to 1 compression, the euro is 9.8 to1, and the 5s is
9.5 to one. The 3sgte is probably about 8.5 or maybe a little more and has semi forged or forged pistons.
More compression = less boost. I think the beams is upward of 10.5 to 1. You are not going to boost what a 3sgte will or a 5sfte, but it will boost.

[markjbutler]

The us 3sge is 9.2 to 1 compression, the euro is 9.8 to1, and the 5s is
9.5 to one. The 3sgte is probably about 8.5 or maybe a little more and has semi forged or forged pistons.
More compression = less boost. I think the beams is upward of 10.5 to 1. You are not going to boost what a 3sgte will or a 5sfte, but it will boost.

thats what i had gathered. So my engine has ~15% more compression than a 3sgte and slightly weaker pistons if they are not (semi) forged so should probably look to run, i'm guessing, 25% less boost? i.e. about 6psi as opposed to the 3sgte 8psi stock? Is it as simple as that or is there more to it?

[manphibian]

Far easier, and probably cheaper in the long run to just put a 3S-GTE in there.

It'll last longer too.

[Vince-Noir]

Far easier, and probably cheaper in the long run to just put a 3S-GTE in there.

It'll last longer too.

The mans right, you could probably source and plumb in a 3SGTE in the UK for less than it would cost to reliably turbo your GT. However, it would be a very fun project so good on you if you decide to do it matey - its your car after all

[DEATH]

I think you have the right idea and you say you don't care much if you blow the motor. Under those conditions, if I was you, I'd do everything the 5S-FTE guys are doing but with slightly lower boost and if you use everything stock 3S-GTE [CT-26, Manifolds, etc] then you will be able to use that stuff on the next motor if you do happen to blow it. At that time just drop in a proper 3S-GTE and you're good to go.
Read Pressure2's sticky on how to turbo the 5S exstensivly. Read up on the differences between 3S, 3S-GTE, and 5S.
You can do it if you really want to, and I say good luck to you on breaking new ground. I remember when the 5s was considered unboostable and "not worth the effort"
Keep us updated

[markjbutler]

Far easier, and probably cheaper in the long run to just put a 3S-GTE in there.

It'll last longer too.

easier and cheaper dont usually go hand in hand!! but i'll take your word for it... although a scrappy/ebay CT26 would do me since not running insane boost and other parts shouldnt run to as much as a whole swap surely? This is all a little pie in the sky at the moment anyhow so i'm not looking to run out and blow a wadge of cash tomorrow so plenty of time for research

although its tax rebate time soon, no?!

reliably turbo your GT. However, it would be a very fun project so good on you if you decide to do it matey - its your car after all

cheers... we'll see what i decide when i have the £££!! theres plenty to do before boost anyway - and thats if i do, of course.

This post has been edited by markjbutler: Mar 8, 2008 - 8:41 AM

[FunkySR]

hey dude. go for it, As said abovem follow the 5S route. Run low boost and you will be fine.

It is your car, and will be unique.