Getting 91 GT-4 Need Advice

[jaybratt]

I am about to get a 1991 Celica Gt-4. It's had a dual friction clutch put in and had the turbo rebuilt. Everything else is stock. Among my first upgrades I want to install an intercooler in the grill and build a cold air downpipe for the turbo with a filter. Would you recommend doing these or something else??? Also woes anyone know what the psi is on the turbo and what it could safely be turned up to after a few mods??? Thanx,

[LaYzIeNoY]

www.alltrac.net
its a forum, and tied to a shop, the shop though is iffy some say good others say bad

has a bunch of information you would want

stock boost on it, i believe is 8psi and it can only go to like 12psi because of the fuel cut, the GT-4/alltrac is equiped with the VSV system meaning that the boost pressure is changed by the computer according to conditions, like good weather [cold air] boost goes up, or goes down in traffic to stop detonation

there is a cheap mod to do to the fuel pump as at WOT there is a volt drop

the only FMIC kit i have seen only seem to want to fit the WRC/CS fronts, if no BOV get one, they do not have a stock unit and it is important for the life of the turbo

get a boost gauge, the stock thing doesn't tell you much usefull info, handling wise, the whiteline rear adjustable antisway bar and front/rear strut tower bars [relatively cheap and usefull any way you want to go]

3" exhuast is also another good mod

a major problem will be finding aftermarket parts, for the engine use 3SGTE[and mr2 SW20 engine parts]

also the syncros on the 2 and 3 seem to be a bit flawed, not extremely big unless the car is grinding 2 and 3

maintaining it is costly, engine bay is cramp

if i remember more i'll try to post it, i have a 1990 one, allin all it is a very good car and extremely rare, i would recommend that you get it, if you are willing to do alot of work yourself, and have a good knowledge of cars, it is not for a new driver 16 year old

[Yaggus]

... that pretty much sums up the most of it.

But i personally dont find the engine bay that cramped.

You can get a custom FIMC installed quite easily under a Veilside front bumper quite easily as well.

Maybe its different where you are but aftermarket parts are quite easy to find over here. As you said, it shares the same motor as the MR2 turbo so many of the aftermarket parts are the same and readily availible.

Get the exhaust done before the FMIC and the CAI. That would get you better gains. Then i would invest in a boost controller to get some more boost happening.

http://www.gt4oc.net

That is an awesome british site. they have HEAPS of info on there.

[LaYzIeNoY]

ya, it is where i live, the US is b1tchy about finding good parts, for my suspension i sent to aussie whiteline

google something called TracFAQ, very informative

oh ya a good cheap upgrade for the turbo is the ST205 version the 6th gens, the ct-20b

[nialusa]

The first thing you should do if you wanna turn up the boost is change the cylinder head gasket to a metal one, to cope with the extra preasure or its gonna go pop, and cause you lots of problems. get yourself a boost guage, an electronoc boost controler, water methanol injection (not as expensive as it sounds) and a charge cooler from an st205 at least. if you get a 3" exhaust, expect boost creep which is bad news and will make things go bang pretty quick. If you get parts from an MR2, expect to do mods as thay arnt all compatable, and can proove more of a head ache than saving up for proper gt4 bits. Forget a mechanical VSV, they may be cheap but they are crap and again unless you know what you are doing will make things go bang. Get a propper electric VSV controller.
For added power, disconnect the engine rocker cover vent to the intake system, its not needed on the st185, but is on the st205, and will help things along alot. (remember to add an engine vent filter)

[91 Celica St]

um eveyone pretty much gave some crazy info, yes you SHOULD change the headgasket if your looking for crazy boost, but its not necessarily needed

if your looking for cheap quick HP, swtich to an aftermarket air filter, get a manual(cheaper than electric) boost controller and up the boost to 15 psi, to do this u must pull the vacum line (and plug it) to the OEM Map sensor, you're stock boost gugage will die but its a piece of shit anyway, pull your cat and get a test pipe made (shouldnt be more than $50) and your already lookin at 200 WHP, about 250 crank

ophtehr than taht buy new 3' exhuast and get a new 3' DP and a new manifold rememebr the cheapest HP gain is weight, so pulling any kind of weight will help, ur lookin at a 3200 pound curb weight car, about 3350 with u in it

[jaybratt]

I appreciate all the info you guys gave. If anyone has more info please let me know. One more question: I have looked at a lot of turbocharged engines and it seems that most of them replace that ugly stock airbox with a filter coming directly off the turbo. Is this better for fast airflow or should it be routed a little further (like 10 inches) from the turbo to keep it away from the heat? Thanx

[91 Celica St]

taht (as well as upping the boost to 15psi) should be ur first mod, put a cone filter (k&n style) on it, and no making it far away will not do anything, either way the air from your turbo is getting passed throuhg the intercooler so it will be cool anyway

[jaybratt]

I need a turbo timer, manual boost controller, and blow off valve. About how much can I expect to pay for each and what company should I get them from? I was thinking Greddy, I'd rather have HKS, but that is a lot more money. Any advice???