Gt4

[Rowbotanator]

im buyin a gt4 poss sat just want to know wot to look for? thanks guys and giels

[T600]

Which one?

Suspension obviously, particularly on the Gen 6 models. Rust, particularly on UK cars or imports that have been here for a long while.

Make sure engine, clutch and gearbox are all good. None of these particularly prone to faults, but the problem with GT4s is that when anything goes wrong it's very expensive to put right because everything is so packed in.

Ian at Toyauto is the expert on these cars, so if you are going to own one, Nottingham's the place to be.

Don't expect it to be cheap to run though. They're thirsty - especially when pushed.

Good luck with it though - they are a great drive if you get the chance to use them to their potential.

[Rowbotanator]

i live in notts anyway lol. i have a concern about the pistons cracking ive seen a few people on here with that problem do you know anything about this? and wot reason sdoes it do this?

[T600]

I think that usually happens on these engines if the boost is turned up too high without appropriate changes to the internals - such as forged pistons etc. Dawesy will tell you better though as the 3S-GTE in his Rolla has had just about everything possible done to it.

But the problem is it's easy to just turn up the boost without changing the internals. People will say they're good for somewhere between 250 and 300 without any mods, but whenever you put more power through a standard engine you increase the possibility of problems. A little bit of extra probably won't do much harm whereas a lot certainly will.

[Rowbotanator]

ive herd they run nice at a bar of boost so i might run at 12 psi with is just a little under a bar. i dnt really want to be stripping my engine lol although i would like the forged kit lol would be nice. im a tech anyway but its a big job

[led-gt4]

mine cracked on standard boost

[Toyotacelicagt4]

Ya don't run 12 psi on stock engine stuff will break boost is hard on *****. You will want forged pistons, rods, steel HG, full exhaust, induction kit, blow off valve before you start upping boost. And I have probably missed some stuff too...

[led-gt4]

Ya don't run 12 psi on stock engine stuff will break boost is hard on *****. You will want forged pistons, rods, steel HG, full exhaust, induction kit, blow off valve before you start upping boost. And I have probably missed some stuff too...

depends on what model you are talking about. the st205 is fine at 1 bar, no need for a steel head gasket as they already have 1. a dump valve makes no performance difference, to be honest i have heard that on some cars they cause over fueling. a re circ 1 gets arround this tho. to up the boost to 1.2 bar on a st205 then i would start to modify the pistons, rods, etc

1st mod is performance air filter, either induction kit or replacement filter, then boost gauge and exhaust. this should up the power to near if not 300bhp in the st205. further mods would be weight removal, ecu, better brakes, and rods, pistons, crank, lightened fly wheel, better clutch, the list is endless!

[dawesy]

the overfueling with BOV is only on st165/185 as they are airflow metered you can fit a dump valve on these but you need a recirculating one

1.1bar is not a problem as long as you run quality high octane fuel (vpower, ultimate etc) led-gt4 if yours cracked a ringland at std boost you had issues or it wasnt running std boost before you had it as ive never seen a stock powered 3S crack a ringland, block yes but not piston.

exhaust, performance panel filter and if possible a decat (OK if you have a pre 95 import) and an electronic boost controller set to 1.1 bar should net between 300-330 bhp.

forged pistons, ecu, injectors and either a hybrid or performance turbo kit (Greddy TD06-20G is a good one) will be good for about 400bhp after that is forged rods, dynamically balanced crank, clutch and uprated fuel system then you can go for silly power but you WILL be rebuilding it every year.

[Rowbotanator]

the overfueling with BOV is only on st165/185 as they are airflow metered you can fit a dump valve on these but you need a recirculating one

1.1bar is not a problem as long as you run quality high octane fuel (vpower, ultimate etc) led-gt4 if yours cracked a ringland at std boost you had issues or it wasnt running std boost before you had it as ive never seen a stock powered 3S crack a ringland, block yes but not piston.

exhaust, performance panel filter and if possible a decat (OK if you have a pre 95 import) and an electronic boost controller set to 1.1 bar should net between 300-330 bhp.

forged pistons, ecu, injectors and either a hybrid or performance turbo kit (Greddy TD06-20G is a good one) will be good for about 400bhp after that is forged rods, dynamically balanced crank, clutch and uprated fuel system then you can go for silly power but you WILL be rebuilding it every year.

so you can fit forge pistons to standard rods? and that would be fine?

[Rowbotanator]

Ya don't run 12 psi on stock engine stuff will break boost is hard on *****. You will want forged pistons, rods, steel HG, full exhaust, induction kit, blow off valve before you start upping boost. And I have probably missed some stuff too...

you can run a gt4 standard on 1 bar equivelent to 14.7 psi so 12 psi is good

[Rowbotanator]

the overfueling with BOV is only on st165/185 as they are airflow metered you can fit a dump valve on these but you need a recirculating one

1.1bar is not a problem as long as you run quality high octane fuel (vpower, ultimate etc) led-gt4 if yours cracked a ringland at std boost you had issues or it wasnt running std boost before you had it as ive never seen a stock powered 3S crack a ringland, block yes but not piston.

exhaust, performance panel filter and if possible a decat (OK if you have a pre 95 import) and an electronic boost controller set to 1.1 bar should net between 300-330 bhp.

forged pistons, ecu, injectors and either a hybrid or performance turbo kit (Greddy TD06-20G is a good one) will be good for about 400bhp after that is forged rods, dynamically balanced crank, clutch and uprated fuel system then you can go for silly power but you WILL be rebuilding it every year.

300 bhp with wot you say good without killing things????? without changing pistons. wot you mean exhaust air filter and de-cat ok if pre 95 is this not safe with the 95 and after. im goin to see an m reg import witch is 95 is it ok to toy with exhaust, air and de'cat and boost at 12 psi (less than a bar) and not have to change the pistons. ive seen a set of forge pistons for sale on eBay. and on fensport they dont come with con rods can they be fitted to standard rods? and is there anything else to look out for?

[Rowbotanator]

only really looking for 300 bhp i'd be happy with that and so would my bank ballance lol 300 bhp easy to reach and as long as it doesnt kill the car i'd do it. i think they have alot anyway. turbo timer and boost control i think will be coming first so i know exactly wot its doing lol want to be safe with it its one of my concerns lol ow and dump valve i love the sound lmao

[Toyotacelicagt4]

Ok so then you can run 14.5 psi on a standard st205 but I should only run about 10 psi on a standard 185RC? And what if I upgrade the head gasket to steel still only 10psi or can it be brought up after that? Last question is thicker HG always better for steelHG or how should I go about determining the right size for me?

[dawesy]

yes forged pistons will fit std rods 12psi is only around stock boost on an ST-205 so very safe.

you can fit the exhaust and air filter on any year GT4 with no issues, the reason i said a pre 95 import is they are not subject to a cat test at MOT time,

so fitting a decat is not an issue

no with a steel HG and ARP head studs you can run upto 1.0bar but it is wise to get it checked on a RR to ensure its safe still.

i run a 1.2mm HG which is fine for most gt4s although if your going to run very high boost >2.0bar then a 1.4 maybe better.

make sure you have a proper boost gauge and most important get it checked on a RR, £60-100 spent on a RR is better than £3000 on a rebuild ;)

[Toyotacelicagt4]

Have no intention of going over 1.0bar just want to up my boost a little to about 11-12psi (as that is still an increase of 4-5psi on a 185) and i want to know for sure that i wont be breaking anything in doing so. My local toyota tells me they have never even worked on a 3sgte before so im a bit hesitant to ask them to do a HG upgrade though....

[led-gt4]

the overfueling with BOV is only on st165/185 as they are airflow metered you can fit a dump valve on these but you need a recirculating one

1.1bar is not a problem as long as you run quality high octane fuel (vpower, ultimate etc) led-gt4 if yours cracked a ringland at std boost you had issues or it wasnt running std boost before you had it as ive never seen a stock powered 3S crack a ringland, block yes but not piston.

exhaust, performance panel filter and if possible a decat (OK if you have a pre 95 import) and an electronic boost controller set to 1.1 bar should net between 300-330 bhp.

forged pistons, ecu, injectors and either a hybrid or performance turbo kit (Greddy TD06-20G is a good one) will be good for about 400bhp after that is forged rods, dynamically balanced crank, clutch and uprated fuel system then you can go for silly power but you WILL be rebuilding it every year.

yea i know it is fine on a st205. i have a bov. I was just stating it happens on some other cars.

As for never hearing a piston crack on standard boost? u can count mine as the 1st you have heard. my car has never ran over standard boost unless it did in japan but surely then i would see evidence of where the wires wer coming in etc. I have heard a few other people with cracked pistons on standard boost. i didnt think it was that uncommon. you have seen a cracked block? surely the block is stronger than stock pistons? its just 1 of those things. 13 years of heat! heres hopin it doesnt ever happen again. got forged in there now.

[dawesy]

new one although i have seen 4's come from japan with dreaded bleed valves!!! that or a batch of dodgy fuel.

heres the split in my block

thats number 3 cyl on the join with number 2. car was running 1.8 bar though at 470bhp

[led-gt4]

no there was def no bleed valve on mine. i gathered as much info on mine as poss when buyin and it was good cause the owner knew the last owner very well and was able to ring him with any questions i had to ask. can understand that block with 470bhp! lol

[4afte]

are those standard pistons in there dawsey?

[dawesy]

nah JE forgies :)

[4afte]

i see, i just splashed out on a set of Wossner's for my rebuild