Stock M20 boost threshold

[slow325isedan]

its an 89 325i this is whats done too it,

OE BMW headgasket (brand new)
ARP's
Spec stage 3 clutch
3076R turbo
Precision 46mm WG

Im running 12 psi with a pretty good tune, AFR's are great under boost 11.9 to 12.3, Just wondering if it would be safe to run 15psi of boost on the stock internals. I plan to do lots of head work over winter but im not going to touch the bottom end until it pops. Let me know your thoughts! thanks guys

[MF DOOM]

run 20. fuck it.

[ColdAsLife]

There is plenty recorded accounts of people running 20+ on similar setups and metric blues even. Just make sure to stay out of detonation keep and eye on your advance at peak torque. Hopefully you have access to E85 which will give you a lot of leeway to go into low 20 lbs's easily given you have the fuel system to support it.

[slow325isedan]

I figured it would be alright to turn the boost up a little just wanted to make sure, my bottom end is very tight also, compression is great all across the board, thanks for the input!

[ColdAsLife]

No worries,

Just work on your map gradually into new ranges and I personally would initially keep advance down to no higher than 16 degrees at peak torque with 15lbs or roughly 205KPA while you get your fuel straightened out if you are using 91 gas.

I figured it would be alright to turn the boost up a little just wanted to make sure, my bottom end is very tight also, compression is great all across the board, thanks for the input!

[kistler#7]

your limitation will likely come from the gt30r. Most people running over 1 bar use a gt35r hx35 or something of that size. You could definitely get a few more out of the 30r though. Your tune will just become more crucial as backpressure increases with the small turbine

[kbdrake07]

I also am building a m20 turbo build.. motor from stock 325i.. 130k on it.. when it pops I have a m52 ready to go in... but any one know how much boost / hp I can get out of a I motor b4 it pops.. I will have a gt35 turbo

Sent from my SCH-I535 using Tapatalk 2

[kistler#7]

http://www.e30tech.com/forum/showthread.php?t=3473

look for the most section on most powerful stock m20 block. lots of good info on that thread. you need standalone and likely someone to tune it.

lots of great info here and on e30tech. just start digging in the FI sections

[einstein57]

I'm at 350k miles. The last 30k have been boosted. I'm at 18psi and will got up to 20 when i install my 044 pump.

[kistler#7]

^testament to good tuning