M35 Turbo Upgrade.

[Leroy Peterson]

hope it fits or at least you can make some room for it...

[BoostdR]

Hence the small form factor Indy car version. Much shorter

[stripey]

The 6258 is more suited to a 2ltr or smaller. I have a 6758 on my 2ltr Wrx and you wouldn't want anymore response. We have a 6758 .8A/R on a c34 Neo Stagea making 20psi by 2500rpm.

Excuse my ignorance and lack of knowledge. Would that mean running out of high end puff but having everything down low? I only ask as ive asked a highflow service provider if i can get bucket of low down torque and power to suit my driving style in tight and twisty roads not interested in long straights and high kw. And well said service provider sent me to a factory replacement turbo running same boost and comes on at around same time... sorry for long winded question hope you can pick it out i think ive even lost it in there somewhere

[joshm35]

When does it come on boost. Was going smaller for better response as not to worried about numbers.

[BoostdR]

You will certainly have response with the 6258...the starter motor will bring it on boost. You will have positive pressure from idle. It's Still no slouch. Have seen a time attack car win several events with the 6258. Only problem is you make risk over spinning the turbine up top to keep the flow from dropping off...which causes other things to drop off ;-)

Edited January 20, 2016 by BoostdR

[joshm35]

Cheers for the info mate. Well that puts a downer in my plans.

[BoostdR]

Cheers for the info mate. Well that puts a downer in my plans.

It will still be awesome, will just be limited to 20-25 psi up top due to the pumping capacity of the 2.5. If you're get onto Borg Warner match bot. It will plot your wheel speed. Check the speed limit on the associated flow chart.

[joshm35]

I would only be running 20psi max

[BoostdR]

167.9k rpm max

[BoostdR]

Here you go, I've done it for you. As you can see the little 6258 will over speed ifthe boost is kept up at high rpm. Drops off even more than I thought. These turbos are good for the 2.5 ltr Wrx Sti that only rev to 5500rpm. You would definitely need the .85a/r turbine housing. Check out the boost pressure level in the table.

20psi dropping off (reliable turbo)

20psi holding, .85a/r (over speed)

Edited January 21, 2016 by BoostdR

[BoostdR]

The 6758 fits the map better but still get into over speed zone right at max rpm. The best fit is actually the 7163 mix geometry turbo.

[joshm35]

Would it fit in the area or would need to be moved

[BoostdR]

Best chance is the EWG version as its much shorter

[joshm35]

Or turbo relocation with fabricated manifold

[BoostdR]

Relocate to where ?

[scotty nm35]

Anywhere else such as where the airbox sits is going to limit the dump flow, I would mount it in the stock location, perhaps slightly tilted up at the front to help straighten the piping a little. Shame we can't swap the starter to the other side like the VQ30det.

If the compressor housing is much larger than a GT30 TO4E? I think you will struggle in the stock location, mine only just fit. Apparently there is a GT35 in one somewhere, but damn it must be tight. You would want at least 10-15mm clearance from the chassis rail unless you want to run solid engine mounts.

[BoostdR]

If I recall the EWG is 40mm shorter

[Ben C34]

Passenger footwell

[Beregron]

Shame we can't swap the starter to the other side like the VQ30det.

Or like a manual swap perhaps

All this info is awesome tho.

[joshm35]

Anywhere else such as where the airbox sits is going to limit the dump flow, I would mount it in the stock location, perhaps slightly tilted up at the front to help straighten the piping a little. Shame we can't swap the starter to the other side like the VQ30det.

If the compressor housing is much larger than a GT30 TO4E? I think you will struggle in the stock location, mine only just fit. Apparently there is a GT35 in one somewhere, but damn it must be tight. You would want at least 10-15mm clearance from the chassis rail unless you want to run solid engine mounts.

limit the dump flow?