its a GT40 with a custom exhaust housing & internal gate.

I'm not sure it is more suited to smaller motors. I have found my set-up to be a pretty good balance of

- Outright maximum power
- Fast spool time
- Everyday driveability (especially in the midrange)

I have only been in a handfull of other turbo carsbut none drove as well all round.


The T4 is a very popular turbo for the 5litre motor if you dont want to spend the extra money on a roller bearing turbo.
It can reach some very good rwkw numbers and still spools pretty quickly.



PS i'm not sure why rebuild cost is such an issue? if you treat the turbo well you should get ooo' sof km from them. Also you get longer life with a roller bearing turbo anyway

So what turbo have you got again pyro??

It all comes down to personal preferance. You like a bit of a safety gap in your power delivery and rev range. I want my turbo's to spool up as early as possible and hold their boost for as far up the rev range as possible. in other words I want a fat and flat torque curve as that is what wins drag races at the end of the day.

It all comes down to personal preferance. You like a bit of a safety gap in your power delivery and rev range. I want my turbo's to spool up as early as possible and hold their boost for as far up the rev range as possible. in other words I want a fat and flat torque curve as that is what wins drag races at the end of the day.[/quote]

You'll get that anyway...

Yeah, not baggin GTs... I'd have one on mine too but I dont see the need on my motor, the T4 works well, but I will be putting a larger comp housing and wheel on it some time soon, that will enable me to get the same power but at lower psi

Its funny with this thread because everything except the T70 are turbo "frames" or cartridges! Even the Garret GT series turbos can be ordered in ball bearing or non-ball bearing versions. GCG will also pretty much put any compressor wheel onto a GT ball bearing centre on a special order basis. Although every aftermarket turbo should be "special order" to ensure it does what you want (within reason).

The T70 is a compressor wheel which obviously has a map from which you can make an informed decision for you turbo needs.

dleach80 what you need to work out is:
how much power you want,
how much boost you want,
what type of boost response and,
any potential future upgrades.

From this it becomes a matter of finding the best compressor map. Garret GT maps can be hard to read due to not much detail so speak with the Garret dealer if you want a GT series turbo. The GT series turbo compressor wheels are supposed to be current technology which results in better power, boost response, etc than other wheel designs regardless of a ball bearing centre.