Running an SC61 on a built B18C1. At lower boost levels, below around 16 the car pulls extremely hard and feels like it makes good power. Above 17 up to 20 it seems like the power levels off, and wondering if I'm not running enough ignition timing. Sitting at 22 degrees at 20psi and about 25 at 17psi.

 

get the car on the dyno. once you get the air fuel set. take a look at the torque curve. peak torque is where the engine is at peak volumetric efficiency and doesnt need much timing, after that when the torque starts falling the engine loses efficiency and will need more timing to keep hp curve on its same path. if your hp curve starts to fall or look jagged at higher rpm you probably need more timing in that area..

 

I was hoping someone would have a general area to start, right now i'm running solid 12:1 across the board

 

What EMS are you running?

 

maybe its just because the difference from 5psi to 17psi is a huge jump in power and the diff from 17-20 is not as extreme. Are you detonating?

 

no detonation, running a haltech e6k.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Overblown-Teg &raquo;</TD></TR><TR><TD CLASS="quote">maybe its just because the difference from 5psi to 17psi is a huge jump in power and the diff from 17-20 is not as extreme. ?</TD></TR></TABLE>

I've never run 5, low boost is 14.

 

Two quick questions for you:

1. What octane are you running?

2. Have you flagged your ignition in Haltech?

If you are running race gas (I really hope you are with 20psi level), your timing sounds a little conservative. On race gas I usually set up all the Haltech/Hondata/DFI to 24 degrees total advance on 110 octane. Since you are running 12:1 in boost assuming race gas, you have plenty of fuel in the combustion chamber to cool it down so you can run a tad bit more timing. There are many many reasons why at 16psi might feel better, and 17-20psi range might not feel as good.

What is your cam timing set at?

How efficient is your intercooler?

What size exhaust?

 

Ok, lots of questions, here goes:
Running 110 octane leaded race gas, my ignition timing is dead on with what the haltech is saying, i have plenty of fuel, big injectors, big pump and 12:1 is easy to obtain with any boost level I've run so far., cam timing is stock, gsr cams, intercooler is a spearco, core is 3.5x24x7, open 3" downpipe at the track.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by boosted hybrid &raquo;</TD></TR><TR><TD CLASS="quote">

On race gas I usually set up all the Haltech/Hondata/DFI to 24 degrees total advance on 110 octane. </TD></TR></TABLE>

At what boost levels?

 

New update. I did a datalog on the advise of efiguy to check my intake air temps in case my intercooler was becoming inefficient. well, discovered on my datalog, that after my car comes up to full boost, right now 19psi, at the top of 3rd gear and on, it begins falling back to about 15psi, which explains why the top gears don't feel as strong. Now I have to find my problem.

 

Well that sux, glad EFIguy was able to give you some advice.

 

Turns out my small air filter wasn't flowing enough volume, now I'm ordering a big k&n, can't go wrong with them. btw, foam filters suck.