Best Turbo For R34 Without Opening The Engine

[TommO]

Kinda off topic I know, but what was your MPH with those runs? Just wondering, as I'd expect 265rwkw to be around the 115mph mark?

[jazza08]

Eboost2 FTW. Might need to take out your cat to hold more than 15psi on that turbo...

[Cubes]

The garret int gate (gt30-gt35) housings suffer a tad boost creep. The balancing of dump and wastegate pipe size is what makes or breaks a setup. An open mouth dump with these turbo's = boost creep, anything less than a 2" wastegate pipe when paired with a 3" dump = boost creep. Then there's the enlarging of wastegate flap size which does work well but requires a strong wastegate spring to prevent the flap being blown open due to back pressure within the scroll.

The HKS ProS housings run a large flap that does get blown open even with stiff actuators.

Rework the dump pipe, reduce the size of the wastegate pipe. Make it harder for the exhaust gas to flow out of that wastegate.

I've never seen it done but there's no reason why it wouldn't work it works int he opposite circumstance - boost creep.

[gtst25]

Kinda off topic I know, but what was your MPH with those runs? Just wondering, as I'd expect 265rwkw to be around the 115mph mark?

113 mph - the best run was with track temps in high 40's, 35 degree day of all things. There is definately is more in it in tuning and boost level/control wise but I'm a bit sceptical on the bottom end holding up - I hate listening to them on a dyno pull.

Currently it's only got the 15 psi wastegate spring - even though it's a 15 psi spring as you start to make boost even 10 psi the wastegate feed will be weakening the spring tension allowing the wategate to blow open eventually. That's why a bleed style boost control and a 20 psi spring should make a difference.

Cheers

[khunjeng]

270rkw, hi-flow and the supporting mods...suspension blah blah

18psi @ just a tad over 3000rpm and holds stong to redline. Who is gonna complain about that.

btw 15psi and 18psi much f**k all difference with a high flow in terms of power....however watch ur mid range torque go through the roof.

[gtst25]

The garret int gate (gt30-gt35) housings suffer a tad boost creep. The balancing of dump and wastegate pipe size is what makes or breaks a setup. An open mouth dump with these turbo's = boost creep, anything less than a 2" wastegate pipe when paired with a 3" dump = boost creep. Then there's the enlarging of wastegate flap size which does work well but requires a strong wastegate spring to prevent the flap being blown open due to back pressure within the scroll.

The HKS ProS housings run a large flap that does get blown open even with stiff actuators.

Rework the dump pipe, reduce the size of the wastegate pipe. Make it harder for the exhaust gas to flow out of that wastegate.

I've never seen it done but there's no reason why it wouldn't work it works int he opposite circumstance - boost creep.

Makes sense but I'd hate to re-work this! I'll try a few other things first.

Cheers

Edited April 22, 2007 by gtst25

[Cubes]

It definitely looks to promote good wastegate flow.

I wouldn't touch the hks dump.

Get a flange cut cut a few pieces of pipe and get it welded up. It is grasping at straws.