Thread: No More ZZP Z7 Turbo Kits...

Originally Posted by Blacknitews6

Just my opinion, but the Z3 crossover looks a little restrictive and not as efficient. The Z7 crossover had separate banks that only merged right at
the turbo inlet. I can see the Z3 is less effective since both banks, all 6 exhaust ports, will actually have to share the same space, in the crossover pipe itself, which can cause the exhaust pulses to hit eachother which will cancel out some of their energy. That might hurt exhaust velocity. I;m sure the Z3 kit will work fine on a mostly
street setup, but i'll always wonder how much more i could make with the Z7 crossover at the same boost level.

It makes basically no difference on most of these setups. You don't have 6 cylinders worth of air trying to get into the same space at the same time. It's more like 2-3.

Pre turbo exhaust size makes almost no difference.

Originally Posted by GTPpower

It makes basically no difference on most of these setups. You don't have 6 cylinders worth of air trying to get into the same space at the same time. It's more like 2-3.

Pre turbo exhaust size makes almost no difference.

x2 the power level that you're doing wont be hampered by the size of the exhaust ports.

Most of the crossover pipe sizes are close to the same, that's not really the issue especially since the turbo is an exhaust restriction anyway. That said I would never install a Z3 crossover. Short of dyno results proving it, I simply cannot believe that a Z7/CT style crossover will not flow and spool significantly better than a Z3. The Z3 kit is the only one that doesn't have smooth merged crossover, and I feel there was a reason for that. Of course, to each his or her own...

Originally Posted by Blacknitews6

So you think the Z3 crossover should make about the same power as a Z7 crossover at 15psi-18psi?
Then thats not so bad. But does it effect spool time at all? Sorry i'm a worry wart...lol.

Power is far more dependant on the turbo than anything else. With the same turbo, you probably won't even pick up a difference on the dyno.

Spool time is dependant on pre turbo exhaust volume for the most part. If have to do some measuring with each crossover to find which is better.

Originally Posted by Blacknitews6

That's what i was concerned with. The Z3 crossover i knew had to be somewhat less efficient than
a Z7 crossover. But i'm only looking to run 15psi and with heads, cam and catback i'm hoping to make
380whp+ I don't want the Stattama kit, so the Z3 in my only choice. I like the Cartuning Kit to, but i'm trying to stick with
ZZP for my parts. But i have time to think about it.

Don't overthink any of it....any kit will make more power than you can effectively put to the front wheels. I have one of the original Stattama prototype kits on my Park Avenue. It uses stock manifolds with a 2" crossover and a 50mm turbo with internal wastegate to a 3" downpipe. Stock motor with blocked off M90 case went 113mph with a race weight over 4,000lbs. Little turbo was all in and couldn't keep up.