I seem to remember the cam advance is mainly an idle thing. I think Todd K and forgive me if I'm wrong Todd, said the variocam reduces the timing at idle. Everywhere else it's added back. Sort of an on/off switch. I don't think it has intermediate settings like the GT3 does.

 

Thanks for the info! The Honda stuff is a bit like that only not at idle, it's for performance on some cars. Can be pretty interesting to play with I had found. Makes sense to control emissions though. The GT3 sounds more interesting however it's apparently not possible to easily make those cams work in a 996 with the OEM ECU etc. <shrug>

 

Marty, the car has been running for about 4 months and 3400 miles now. We did a 1k mile break-in and then tuned the car. The car felt great and ran strong at 1.5 bar but I wasn't 100% satisfied with the power. So, John spoke to Todd K and told him I wasn't happy with the power so Todd said since you have the O-ringed heads and liners you can crank up the boost to 1.7-1.8 bar no problem. At 1.7 the car made 753 rwhp on a Dynapak 4000 like the one Todd uses. I thought this # was kind of low considering I have a 3.8 with 3076.82 a/r's and running 1.7 bar. After the dyno run John in conversation with Todd realized we were using 2.5" intake pipes and 2.5" exhaust wiht Evoms IC's. Todd said this was a major restriction at this power level. So now I have 3" intake and exhaust plus Todd's 4.5" massive IC's. It is now a different animal the boost response comes in about 200 rpms earlier and John had to retune the ECU. I think we probably gained about another 50 hp at the same boost. I plan to dyno again next week and I will do a write up on the whole build with pics.

 

Agree that does sound a little low for that displacement, you may find more than 50HP IMO! Check for vac in the intake pipes to the turbo to make sure all restrictions are gone, intake side is VERY sensitive to being corked up. You should be able to figure out how much HP you get per PSI of boost and see if that has tapered off significantly to try and figure out if there are restrictions.

Are the head and cams stock? If so is it possible you're hitting a flow restriction there? On my 3l Supra I hit the flow limit on the cams at around 720WHP. Guys with the SAME setup and slightly bigger cams gained 100+ HP! I was at close to 2BAR with my turbo and HP per PSI had tapered off pretty good which told us we had a restriction. If you do a few runs at different boost levels you ought to be able to see this I'd think. Your motor is significantly bigger, it ought to make a good bit more power at similar pressure levels I'd think.

 

Yes, stock cams and heads. I guess it could be possible its being restricted by the head and cams. Definitely no vac leaks, John checked various times throughout the tuning. Like you said maybe I picked up more than 50hp. We'll see next week what the dyno has to say. 800 rwhp was my goal...if I make it I'll be happy.

 

No no, not vac leaks If you measure for vac between turbo inlet(s) and air filter at WOT and find significant vac then there's a restriction that can be improved upon. It should be as close to atmospheric pressure as possible. Like trying to suck a thick shake with a straw, when there's restriction at the far end the straw itself will measure vacuum. Make sense? Depending on length of the intake pipes and position of MAF etc. you can even change the measurement point to find where the restriction resides - MAF, filter, etc. Turbos, heck even superchargers, really do not like having their intake side restricted!

You can also measure for pressure in other places to find restrictions too. Say on either side of the intercoolers, if there's a big difference in inlet and outlet pressures you've exceeded the flow limits of the intercooler. Likewise high pressure readings prior to the muffler in the exhaust tell you that the muffler or perhaps catalytic is an issue. Measure pre and post catalytic to check it's restriction.

Hope that's clearer, also hope this is NOT a cam issue as that's a good bit more money to solve! Some testing like this is an easy way to narrow down possible perfomance bottleknecks and sure costs less than swapping parts. Please do keep us posted on your progress as you may help document limitations like what I'd seen with cams on my last project.

 

I'm not running cats or mufflers, just resonators. Thanks for the info I will look into doing a vac test.

 

any updates which 3.8 kit did you get?

 

having the injectors and keeping the boost 1.2 - 1.3 max would rods and head studs still be a safe investment?

 

dont open the motor up for anything less then 1.4+ keep it stock trust the guys that have already done it its so expensive for not too much gain unless u go way big.

 

ecu controlled... and it is a big jump. I am still dialing it in on the standalone.... stock DME controls it, and I "monitor" it Big change in AF during the switchover and after speaking with Tony, I might just control it with the standalone. It's mainly for emissions and idle(litttle to no load).

Tony, if you read this, can you verify if I will get a code controlling it with a different source? I am pretty sure I will.

and holy old post Batman

justin

 

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