Ok, I went to the dyno last night/this morning to get my car tuned.
Here are my specs on the engine..
2nd Gen B16 head
Supertech springs and retainers
ITR cams (But now I'm not so sure anymore)
Skunk2 Pro Series IM
Stock TB
Stock Ignition

B18C5 Bottom End - Just rebuilt 81.5mm
9:1 comp Eagle H Beams, Wiseco Pistons

Peakboost topmount kit
Garrett 60-1 Turbo
44mm Tial WG
2.5" Charge Piping
3" Exhaust, no cat, chambered 3" Magnaflow muffler
HBC manual boost controller

1200cc Injectors
255lph fuel pump

Neptune RTP software
94 Octane gas

I made about 360whp, 266tq on my setup last night. Thats around 7500ish rpm, where afterwards, the engine was falling on its face, losing power. Mechanical timing is dead on, ignition timing is dead on.
NGK #8 plugs, checked them twice during tuning, checked out fine.
Boost IS creeping, from 13-14psi to about 15-17psi
Everything checks out ok, didn't run into any noticeable problems...

Except the fact that on my B16 Block - 9:1 comp, Eagle H Beams, Wiseco Pistons, 81mm Bore - it made 370whp and 244tq - that was boost creeping to about 16psi, revved to 8500 and a 38mm wastegate, on CROME, with 780cc injectors, running over 80% duty, and a Magnaflow 3" steel cat.

The car makes good power though. I see more hp, especially tq sooner, and midrange, the engine definitely makes promising power, but it starts struggling at top end to make more.

Now, the cams are a long story, and I can't say for sure if they really are ITRs, but they're the same ones I ran in the B16 setup.

My tuner had to lean it out at top end to make more power. We even disconnected the muffler to have it straight through 3" to see if that was my problem, but it didn't make a big difference, where we could even say that the muffler is being way too restrictive for this setup. Obviously it DID make a bit more power without it, but nothing phenomenal.

We were thinking that the cams are the major drawback to this engine performing the way we expected it to, especially with a hollow cat, and controlling the boost would be much more beneficial to tuning more precisely.

SO....! Maybe we're thinking too much, or not hard enough, but if anyone has any suggestions, please feel free to toss them at me. I tried to supply all the information about my setup that is coming to me right now. If you have any questions about it, ask away.

Sorry for the long-*** post, I made an attempt to keep it as simple as possible, given the situation.

 

so if i am understanding this correctly, the engine dyno'd fine and you put it on the street and the engine falls on its face up top?

 

No. All this happened on the dyno.

 

post a chart

 

Just a minute.... so same head and cams as the B16, and you wonder why you lost POWER and gained TORQUE with the bigger motor?


Bigger motor NEEDS bigger cams to breath at higher rpm.

You got the expected results if my assumptions are true, and of course you would have to lean it out up top, since the efficiency is dropping.....

Try increasing overlap on the cams.... but in the end, I think you'll need more duration.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Toma &raquo;</TD></TR><TR><TD CLASS="quote">Just a minute.... so same head and cams as the B16, and you wonder why you lost POWER and gained TORQUE with the bigger motor?
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Yes exact same head and cams as the striaght b16a setup. Well I guess I just expected to make the same or more power and torque then the striaght b16a setup.

I just didn't think the ITR cams would hold me back that much. I will try to get some graphs tonight or early this week.

 

I'd almost wonder if messing with the cam gears would help. Since you have more backpressure in the manifold on the larger motor at the same RPM, you'll run into issues if there is too much pressure for the amount of overlap. Usually it takes a big cam and lots of boost to make that happen.

Aside from that, there's not too many reasons to make as much or more power near redline. At least theres no major problem since it makes more midrange.

 

So would you suggest maybe throwing on a set of cam gears and playing around with them, as opposed to putting cams in?