Thread: Think I went with too big of a turbo...

6k VVL seems to be a bit better then 4k. I plan on running on exhaust cam only, since it provides the least amount of overlap, and seeing your post form last year (that you posted in this thread today), I am more inclined to try it. First I need to fix the oil drip. Either the oil pan or one of the seals is leaking. My oil pressure is on par still though, and I make sure to check the oil levels often.



Yup definitely felt like a bog, kind of like hitting a fuel cut revlimiter. I also noticed how innacurate the factory tac is, it's about 200-300 rpm lazy. Thus it's hard not to bounce of the redline when your tack is usually behind a bit. Luckily with a spark and fuel cut rev limiter, hitting the rev limit is now softer then the VVL bog

Now does 4800rpm full boost sound about right for this kind of turbo (it is journaled afterall) Or should I expect better spool times with a less restrictive exhaust manifold/less overlapped cam?

I think the boost is kinda lazy, but it seems about right for what you have. Getting the exhaust side to actually spool the turbo is the trick. I see 15psi by 3800rpm. But our setups are at extremes now lol.

For what it is, I still think you could improve spool with some slights mods.

I was just thinking about this boost/backpressure ratio thing. Now there are a lot of variables to consider, but consider this: Our 86mm pistons have to force exhaust out of the cylinder. How much force does that take? Depends on the amount of backpressure. Typically, you see a psi/bp ratio of 1.5. 1.5psi backpressure for every 1psi boost.

Taking this area of piston into account, on 10psi with 15psi backpressure, there would be 21ftlbs of force keeping the pistons down (cumulative 4 pistons).

So even on 10psi, you could see some gains. 200lb at 7krpm is 266whp. But 205 at 7k is 273whp. More boost and more backpressure make for bigger losses. Just something to think about. My engine saw well over 40psi backpressure on 24psi boost. If you had lost 30lbft due to pumping losses, that is huge! Getting the backpressure/psi ratio as low as possible is the best thing for the VE engine. You can make a ton of power getting close to unity!

Did jp respond to your pm about cams?

One thing I will say is that jp loved the vet cams even on his set up due to the responce

At this Point these graphs show nothing more than what tuning can do when you tune ideally for what each individual car has. These graphs have nothing to do with on topic but rather off topic. Here goes my magical acer laptop at work (Ashton).
Jwt Ecu. I advanced and retarded the dist. And I gained and loss at either end of the graphs so this was a medium between both.

My specific tuning for my setup

Peak hp is one story midrange is there now. You can clearly see Vvl activation in one graph and the other none.
Next thing to notice is jwt would lean out uptop. In order for me to fix that I would have to add fuel pressure that would make the car richer in the mid and lazy.10.8 afr in the mid and would go up to 11.7 uptop.

At 7800 jwt and my ecu were close in hp, but the midrange there was no comparing. The car went from spinning top of third gear in the high rpm too just raping the tires instantly in third and spinning fourth effortlessly. But we all no spinning is not winning,lol

Good info, It seems like getting a free flowing manifold would be the best solution. But for the fitment, I don't know if I can squeeze in a equal length mani. P11's have less space since the radiator doesn't hide under the radiator support like it does on B13/B14's. I barely have enough space for 2.5" slim fans



Nothing yet sir. I would love to use VET cams even with a tubular manifold due to torque/low overlap. I am a little concerned about how loud they are since I'm trying to stay semi stealthy (and like it to be quiet on the highway).

Mazworx Custom?

good stuff gio!

I used to be all about big boost and power, but I would trade that for a smooth powerband that is broad, linear, and responsive.

tubular mani is a great way to go V. But it is a little more expensive. I would get a protech shorty manifold. Decent price and should work pretty well for you. EQL is overrated. But if you are on a budget, i would def drop in the cams. I mean, you arent going for 9k rpm or 500+whp. the cams would put you ahead and you wouldn't have to change the setup.

I ran the VET cams for 2 years. Try driving around with your exhaust cam on and see how loud it is. That's basically how it sounds with the VET cams. It is louder, but not much. I didn't even notice it until I switched back to the VE cams after the tubular was put on.

I did see Jp's dyno of the VET cams and it was very impressive. For different reasons than his SR16 cams. the powerband was huge, the torque flat, and the massive amount of power available made it look like a supercharged ZR1.

It made 500+whp over 3000rpm or something like that. Just massive.

he about shit his pants when my b13 went on that thing haha