standard turbo's

[letemlaf]

an s13 has a T25, an s15 has a t28 (i think thats right).

what size turbo is in a standard r33 gtst, and what are the main problems that appear with these.

can you run much more that 1bar through them?

[rob77]

Not 100% sure what they call it but I think its a t28 and I wouldnt run more than 12psi through it for a long amount of time as it has a ceramic exhaust wheel which loves to fall off when you run more than 12psi for too long.

[Mr GTS4]

the R33 turbo's aren't as bad as the R32 ones. you can run 1 bar but remember if you are running 1 bar your not running that ALL THE TIME. so just remember that just don't flog the crap out of it all the time.. it would help having a FMIC and exhaust and pod the usual things. the R33 turbo has a T3 flange so i think that is bigger than the T28.

[letemlaf]

thanks guys,

what is a T3 flange?

my mate has a 93 180sx running 1bar constantly, he rarely ever drives faster than his grandma, is that ok to run 1bar as he does?

[Guest INASNT]

The accelerator and when u change gears is a great boost controller. So even tho your mate is running 1 bar if he drives like a grandma then the turbo never actually sees 1 bar.

[rob77]

T3 is the type of flange on the turbo where it bolts onto the exhaust manifold so when choosing a new turbo make sure it has a T3 flange on it or you will have to have an adaptor plate made up for it or a new exhaust manifold. Personally I would never run 1bar through my turbo for any length of time be it short or long unless I had the funds around to replace the turbo. We have no idea when the turbo will call it a day but its safe to say that at 12psi (which is about double the factory setting) it should last a long time. I have seen on an r32 GTR the cermaic wheels come off when the car had only been run at 1bar for a very short period... I think it was set to 1bar for that day and they came off pretty quickly. He then proceeded to fit a couple of HKS gt2530's and now makes 400hp @ wheels Unless you have the funds around, dont try it.

[PRO_32]

I dont think the turbo's are really as bad as ppl say they are, I think it's heat that kill's them and not boost.

[rob77]

I dont think the turbo's are really as bad as ppl say they are, I think it's heat that kill's them and not boost.

Correct... and what causes heat? more boost. Turbo's have an efficiency range, ie: a certain boost level that when exceeded the turbo makes more heat than power. Ceramic exhaust wheels hate heat and therefore you should run then at safe boost levels.

[PRO_32]

It's not just boost that creates heat, Id say it's the condition where constant high levels of boost are experianced eg; On track that causes delamaination of the exhaust wheel

and Not say running 1.1bar on street where you only really give it a quick squirt here and there.

[rob77]

Like I said before its an unknown quantity. Some people run 1bar of boost all day every day and have no problems and then some people turn the boost up a little bit (like this guy with the r32 gtr) for an event, it was a motokhana, and his ceramic wheel fell off. Going back to what the original question is "can you run more than 1bar", the answer is no and if you run 1 bar for any length of time be prepared to change your turbo. At the end of the day this is a forum and whats said on here should be taken with a pinch of salt I suggest you talk with your mechanic before doing anything if they know what they are doing they will point you in the right direction. If you dont want to or dont have the funds to buy a new turbo, dont run more than 12psi oh also dont go thrashing it in 40 degree heat like we have in perth at the moment, the car will probably ping.

[rob77]

oh also the gain of HP from 0.8bar to 1bar to 1.1bar wouldnt even be worth the risk, you might gain 5-10hp tops, the turbo is running out of flow.

[letemlaf]

i heard ball bearing turbo's should outlast the life of your car, are they able to take much higher boost and larger degrees of thrashing?

to replace a standard r33 turbo would a ballbearing be a sensible option?

[rev210]

letemlaf,

the turbo bearings might outlast other parts on the car but, the seals and fragile ceramic exhaust wheel are another story.

The bearings have absolutely nothing to do with how much boost you can run btw.

ballbearing Vs plain bearing offer longer life span and slightly better response, so ballbearing is a good thing if you have the luxury of choice. The factory turbo is not a T28 it is a hitachi thing that is close to the same size, it does have a standard T3 exhaust flange as mentioned. It has a ballbearing core and has a ceramic exhaust wheel that limits the everyday boost to 12psi or less if you would like the turbo to last a long time. The good news is that even with this little turbo you can quite easily get an R33 into low 13's over the 1/4 and even a 12.

1bar of boost is not worth the wear on the old tubo for the almost non exisitant improvement if offers. I ran low 13's with the old gtst with 10psi ,a stock intercooler and little else.

[letemlaf]

is 1.3 bar boost too much for a ballbearing turbo?

[gobiz]

I plan to run 1 bar on my stock R33 turbo but I've got a few other things:

1. I drive slower than my grandma except for a short squirt here and there

2. HKS GT FMIC, exhaust, pod with CAI and heat shield (home made tho)

3. Full ECU + bosch 910 fuel pump

4. If I stuff my turbo, it'll be a really good excuse (to convince the missus) to get the GT2530 hehehhehehe

[predator]

There is no point running 14psi (1bar) just because 14psi > 10psi and sounds better. And everybody is telling you this! and yet you still wish to run 14psi? Basically all turbos have an efficiency range, after which running more boost is mainly doing more harm then good. You may get a whole 5rwkw or so (which you won't notice when driving), but even the extra 4psi you'll notice:

* extra heat produced (more in the engine bay, never good)

* will take longer to spool up and therefore lag.. although true, bees dick in it

* very little power increase over say 10psi.

And why trash a perfectly good turbo that you may get $500 for on the 2nd hand market if still in decent condition?? Thats a $500 saving on your next turbo purchase.

If you imagine a curve, basically it begins tappering off with diminishing returns each PSI above 10psi or so. Therefore while 1bar is 40% higher than 10psi, you're definitely not going to get 40% more power..more like 5% if that.

10psi-12psi with the stock turbo is generally ample on an RB25DET, and if tuned correctly will give you 170-190rwkw with the setup you've got and its been proven over and over. Thats plenty, and with the other support systems (most importantly tyres and rear end setup), like people are saying, enough for low 13sec 1/4's if thats your thing.

Initially everybody thinks "more boost is better" but as you go on and learn a few more things, you find thats not always the case. Like many, I've experimented with higher boost, but everytime i get it tuned, the tuner goes "ba.. why bother, you're getting stuff all extra power" so back to a more reasonable 10psi (@ last dyno 183rwkw) where its been for at least 6 months now.

[Evil]

i agree with what has been said... my car is running 9psi and dynoed 180rwkw... all with just an fmic, exhaust, air filter, safc II and avcr

[gobiz]

Alright.....thanks for letting me know...

10-11psi it is then