I was looking at my car yesterday (its being repainted) and I got to thinking, ever since I had the APS system installed I've been hitting 10psi even during the hot and humid summer here in Atlanta. I'm going to be driving up to GRD to have my car tuned by Tuan and I know his stock block 350Z is making 500whp @ 11psi and has been for the past year.

I'm also noticing a lot of the G35's and 350Z's he's tuning are being tuned to 8.5psi.. APS was making 470whp on their G35 and I'm thinking about going that route or maybe even shooting for 500whp. I have the resources to rebuild the engine if I have to which makes this decision a little more enticing to me now, I'd really like to see how much hp we can push on the stock block without going overboard.

What do you guys think? even at 10psi my EGT's stayed relatively low and the a/f held at 12:1 over 5000rpm's up to redline. I switched bumpers so I think the combination of water injection along with open air to the intercooler will keep everything where I want it to be as far as cooling goes.

 

Well if you have the resources to rebuild the engine that's all good. But if you blow a rod through your block, do you have the resources to buy a new (or used) block and rebuild that? If not, I'd say build it up before you turn up the boost.

Keep in mind I'm somewhat of a conservative when it comes to FI. I guess I'm from the "better safe than sorry" camp.

 

I'm thinking about just building another engine on the side while I try this.. not totally sure though. Personally I'd just like to try and push the envelope, everyones going with such a safe tune but we're only a year or two into FI with these engines so what can we really compare safe to?

I know of the engines that have blown in the past but I think the right issues have been addressed since then (tuning, oil starvation, cas wire) and now 420-450whp is the sweet spot whereas before it was considered blown engine territory.

 

Im sure the guys you see getting 450-470+rwhp at stock psi have aftermarket cams, free flowing exhaust with no back pressure, so you'll need to get an exhaust with 2.5"-3" piping besides your aps test pipes. Lately Im seeing alot of hugh HP#'s getting thrown around on this forum and 350z forum, but hardly if any posting their dyno charts. Would like to see what psi, A/F#'s, HP/Trq curves, 91/93 oct., dyno machine used, etc.etc. ...... Since your driving to GRD, get the aps true dual exhaust and aps plenum and get tuned by Tuan same time. Should get another 30-40rhp. If plans are for more HP, would benefit you to look for another motor to build. Will make it easier later to do a swap.