Turbo question - what's the difference between a T3/T4?

Hey, what does the "T" rating on a turbo kit mean? Is it size? Power? A friend and I are talking about it. His mom has a 3000gt VR-4 (TT) and he was wondering what kind of upgrades he could do when/if he buys it from her.

So we started talking about turbo's, and I didn't know what the T4/T3/T2 stuff meant. I'd appreciate any info.

- Dzur

[CD5Passion]

i thought it was size, but I'm not very knowledgeable on turbos...yet
also isn't size relative to the power it puts out..someting like a small turbo is good for lower speeds and a larger one is good for higherspeed?

I was under the impression it was how much air the tubro could move. Depending one what you wanted to do or what car you are driving one may generally work better for you.

[ebpda9]

well usually turbos that have a tin their names are made by garett. well a t2 < t3 < t4. a t3/t4 is a hybrid turbo: the turbine of a smaller t3 with the compressor of a bigger t4. also any of the t series come in different trims and a/r ratios. should wait for our turbo guru thermal to shed some lighton thios whole issue

[Duckydos]

t3/t4 is a t3 hot side (exhaust side that creates the spool) with t4 cold side (intake). It moves more air with the same lag as a regular t3. Even then, you have different trims (pitch on the blades) that will change the way the air flows as well.

Turbo sizing confuses the hell out of me and I am not really a good source, but just keep this in mind, the bigger the T number the bigger the turbo, the longer the turbo lag, more power.

-Ducky

[Shaved &/or Laid]

i want a t1000.

[Duckydos]

Good luck spooling it.

Originally posted by Duckydos
but just keep this in mind, the bigger the T number the bigger the turbo, the longer the turbo lag, more power.

Thanks that sort of clears it up for me.

- Dzur

[Duckydos]

The exception is to that little rule is like the t25 or t28. Just think of those as T2.5's and T2.8's which of course are smaller than T3's or T4's.

-Ducky

my impression of the sizing is like large automobiles

the larger the turbo the larger the car would be ( stay with me) it takes longer to spool the turbo ( get the car moving) but say at the same speed ( psi for the turbo) the larger turbo / car would have more energy... such as a t25 working 10psi might make 200whp, while a t3/t04e 60 trim like mine might make 300whp @ 10psi...... although the t25 would probly make the 200whp about 1,800rpm's before mine ( reference to moving a larger turbo or larer car) i still preferr the suspense in waiting for it, and having more than a smaller one....

Ah, thanks.

- Dzur

[GT40FIED]

Originally posted by Shaved &/or Laid
i want a t1000.

You want a Terminator? Haha...Get it...T1000? I've actually got a friend with a strip-only Capri with a "Y2K" turbo otherwise known as a T-100 which is a 100mm turbo and (I believe) the biggest you can get without going industrial. As for the "T" in the name, like Stefan said, it's just a Garrett thing. IHI and KKK (no...seriously...it's a company) turbos don't have the "T" designation. A T3/T4 is just a way of getting more air without the added lag of a bigger turbo.

[VR4_Craver]

Originally posted by GT40FIED
IHI and KKK (no...seriously...it's a company) turbos don't have the "T" designation. A T3/T4 is just a way of getting more air without the added lag of a bigger turbo.

The KKK's turbos are generally found on the VW cars like the (I think its this one) GTI VR6 Thats the turbo one can never remember) Its turbo "code" is KKK K03

[nonovurbizniz]

kkk's come on porsche's and VW's... They're pretty good turbos...

other things to keep in mind when considering a turbo is if it's water AND oil cooled or just oil cooled...

And as to what kind of bearings it has... ceramic ball bearings are the best but also the most expensive...

If I were you the only "upgrade" I'd do to your mom's VR4 would be turning it into a 300z or supra... cuz those things SUCK SUCK SUCK...

Good luck with it though.

[VR4_Craver]

Originally posted by nonovurbizniz
If I were you the only "upgrade" I'd do to your mom's VR4 would be turning it into a 300z or supra... cuz those things SUCK SUCK SUCK...

Good luck with it though.

LOL...He does have a point from the factory they do kinda suck because they weigh like 4400 pounds. Best bet is go as light as possible I can link you to a few people that have 12 and 11 sec vr-4s if you want

No thanks. I'm not a big fan of the cars myself (this is a buddy's mom's car). He just wanted some info on it, but I'd definitely agree on the heavy part - they weigh too much.

- Dzur

[lawkmlaw]

nice