Hi everyone!
I'm doing a budget b18c4 build.
Unfortunatelly i bougth a block which have be bored for last oversize.
Setup:
- 82mm nippon racing turbo pistons
- i-beam forged rods
- ACL bearing, orbit oil pump
- ported head with gsr cams
- skunk2 66mm TB & blox IM
- special cylinder support system ( i attaches a photo from my friedns engine)

My question is how far could i go safely? My plan would be max 350WHP. Should i choose GT35 ? I heard low end trq could be kill the overbored sleeve! Please help me out!
Thanks for the answers!

 

350 wont be a problem, I’ve seen stock sleeves go past 600whp, maybe not after going to 82mm but you should be well within the limits as long as it’s tuned properly

 

350whp wouldn’t be an issue at all as long as you have a solid tune. A gt35 would be much too large for your power goals, stick with a gt30-sized turbo.

 

Thank you!
Okay im going to go with 3082.

 

If you want 350 to the tyre on 93 octane (or 100 EU) get a GT35 sized turbine with .63 a/r turbine housing.

 

It will handle about 20 wheel HP less than when it breaks. Heheheh
Seriously, 350 is doable, but you need to keep the ignition timing REALLY Conservative between 4700 and 6700 RPM. A GT-3037 or GT-3071 will do it and a GT-35 will do it easier (lower boost). Use the .63 A/R exhaust housing on either.

 

Yes I definetly use EU100 gasoline ( all of my cars btw)

 

Beacuse of the peak torque area? If i choose GT35 it moves up, wouldn't it be safer? Thanks.

 

Yes sleeves die from early torque. Its not hp that matters but torque. Smaller turbo -> higher boost required to hit your target -> higher torque -> soon or later bye bye sleeve.

For 600hp from GTX3076 needs 30-35psi
For 600hp from gtx3582 youll need 20-25 psi

Also you can do 600hp on stock sleeves if you go for 10500 because you will only need 40kgm of torque
600hp with 8000 redline require 53kgm of torque

 

I don't know what should be the safe rev limit,but I'm goint to use my Brian crower inner valvesprings and retainers with OEM Honda outter valve springs. My friend destroyed his OEM cams and rocker arms with aftermarket double valve springs. I'm plannig to stop rev it past 8500rpm. CR will be around 9.5-10:1 because of the decking. so if my consideration is right i will have boost from 5000. And also i'm using stock head bolts so maybe at 10-12 poundsi reach my target, if im right... Thanks for help anyway!!!

 

Balor makes some great points. Keep the torque down and the engine will live longer, although I would go with the slightly smaller 3076 turbo vs the 35 series. The smaller turbo will bring boost on a smidge sooner, and I think you’d still only be talking about 15psi to make your 350. Id like to think you’ll still have an engine that will last a while.

 

Not necessarily. No need to go as large as a GT35 to get 350whp, even on pump fuel. Build will run mechanically fine, but behaviour will be laggy, and rather unresponsive at the lower boost pressures it will be in order to make that 350whp. Stick to the GT3076R or similar sized family. The GT3082R has always been a mismatch, and I'm surprised is still in existence.