Hey guys, new to the forum..

I've researched this topic a lot and keep reading mixed reviews and opinions.

I have a semi-built CA18DET I'm putting together at the moment -- custom Wiseco 9.5:1 pistons, k1 rods, Tomei 256 poncams, etc. I'm currently going to run a Sr20 t25g and a mines ecu till I get up some more funds for a bigger turbo, injectors, and tune..

On my old stock motor (recently spun a bearing due to an oil leak and faulty dipstick readings) it would only run well with the CAS almost all the way advanced (assuming due to the mines ecu).

I'm kind of worried about detonation with the bumped compression and the timing the way it is, so basically I came here to get opinions on whether or not you guys think I would be fine running the sr t25g on stock boost for the time being, or any personal experiences.



Edit: I was just thinking, I bypassed my knock sensor by running two 500k resistors in parallel, but just realized I didn't ground the end out. Would this have caused me to set the ignition timing so advanced to make up for pulling timing? Or does it make a difference if it's grounded or not?

Has to be grounded, or the resistors don't do anything. That could be the cause for the improper ignition timing and having to have the CAS advanced.

That compression ratio and turbo will be fine on pump gas, but as the boost levels increase, you may start to be a little limited as to how much boost you can run. You may also consider water injection.

I'm VERY familiar with high compression and boost on the CA. (I was running 10.2:1 + boost). The level I was at was impossible on pump gas. I had to switch to E85. Car was a dream after that.

What size turbo there Float? I'm wondering if you could improve the knock threshold a bit if you went with a larger compressor wheel at low boost. Lower the compressor outlet temps a bit and push more cfm at the same time. Pair with a high-flowing exhaust manifold and turbine to keep backpressure down and thus reversion and you might be able to slow the burn down even more...

The turbo wouldn't snap instantly to full boost like a t25 will but the compression and increased mass flow from the turbo at even a few psi would ultimately make for a very torquey, quick car.

I'm just spitballing here though, I really have no idea what kind of fuel you'd be able to get away with on the above setup...

On another note, ditch that Mines ECU asap. Ones I've seen they bump the timing a little bit in the top end. Not good, especially on most CA's.

I was running an S15 SR T28 with a tubular equal length manifold. I do think that if I had run the stock manifold, it may have cut down on the reversion and may have helped the situation, but I'll never know now as I had to bore the engine out for this rebuild and I dropped the compression back down. I was only running 7 psi and it didn't matter how much timing I pulled, it would detonate when it was hot out or I was on the throttle for a while. I was going to try a water injection setup, but E85 became available locally, so I just switched over and I've been happy with it since.

Sorry for the late reply. Been busy getting the motor back together.

I'm picking up a stock ecu today and should have it running midway this week or so. I appreciate the replies. I'd post some pics of the build if I knew how loll.