presumably It's the engine management. If I could get the knock out of the picture I think another 4-6psi will get him 250ish wheel.
I'm basically going to tell him to get the stock MAF on there so the timing is in the window it should be. Also the intake side could perhaps use some more spring pre-load.
Well anywho. Zenith Diaphrams? huh? lol electronics is fun!
The ol solstice will be spending the next few days in the dyno shop. I still haven't made an intake. Im using a piece of 3" neoprene brake ducting hose and a C6 airfilter.
I want to try
1)running it as is
2)Running it with nothing on front of the turbo.
This will illustrate what the proper size should be for the Air intake.
then I will build the intake without moving the car (you can change HP just by strapping it down different.) to see what we end up with.
The I'll run it with just a pipe extension with the downpipe & O2 to see if the Exhaust needs to be bigger.
Then we'll see (pending pressure drop) what garrett intercooler core will fit best and fabricate a new intercooler for it.
if doing blow through maf, simply do a stubby 4" pipe and/or filter
I think I'm on the same page as you. SInce the car has a frontmount A-A intercooler and a very efficient turbo, i think breathing outside the engine compartment is less crucial.
Id rather have 10deg warmer ambient air with ZERO depression at the turbo inlet as opposed to ambient air with a 1psi loss thru the filterpipe. Makes for a lower pressure ratio and less charge heat. (tail chasing)
That's a very interesting point BTF! I know of many shops who are fine with pulling air from the engine compartment via a stubby pipe who say pulling cooler air isn't much of a factor... Just didn't know why this was the case.
If you pull in 150 degree air, the intercooler isn't gonna take that all the way back to ambient.
If you pull in 60 degree air, that less load on the intercooler. It make as significant of a difference on an intercooled turbo setup as it does with NA, Nitrous, or Roots blown for example..
I think what BTF is saying is that if the turbo gets air more efficiently (IE, no pressure drop vs a 1psi pressure drop with a longer inlet tube), it doesn't need to work as hard for the same outlet pressure. Less work = less heat, so they somewhat equal each other out.
We won't see a 90 degree diff in temp from cold air inlet to a stubby inlet... at least at speed.
Sounds like a great opportunity for scientific testing.
You're right ender, at speeds it could even be within a few degrees of ambient.
However, I'd be floored if I saw a 1 psi drop through an intake... I've never seen that.
I've hooked up vac gauges before, and If I saw even 1 HG INCH at WOT with the stock intake, I'd be pissed...
There should be no discernable difference in pressure with a proprly designed intake.
Well I'll start correlating data and post up the dyno .WMF's
We started at 14psi got 232whp a 5400rpm.
We got the boost spikes out of the controller and got it to run a more steady 16.5psi.
Im doing the runs in third since it's a 4k lb roll.
With tuning we are at 249.xx whp at 5600rpm. After that you'll notice from the graphs that it takes a notable turn downward.
Im staying at 16.5psi until I fgure out why the crook in the power is there after 5600.
I figure if the graph continued on the slope the line was traveling it would have been 270ish.
There is much top end power and low end torque to be had in the cam timing.
Next is a 4" intake elbow +filter. If that doesnt fix the nerf in the power curve up top I'll go lookin at the exhaust.
So to reiterate we are
Stock motor
stock exhaust
stock intercooler
unclamped MAp/iat2's
Gt3076R w/tial 38mm
catless DP.
3" neoprene brake ducting hose (with integral wire) + aftermarket c6 filter..
camtiming and PE tuning only
249xx whp @5400 & 16.5psi.
so by 25psi Id say were on par for 320-340's.
It jsut might not happen thru that exhaust/intercooler
Last edited by BaldTurboFreak : 02-08-2008 at 05:04 PM.
Maybe I am wrong but the exhaust to me is restrictive.
You 1st have a small resonator on the pipe and then when it gets to the muffler is pretty much a T. The flow is to constraint IMHO.
I'd would venture to say that with the SOLO street racer at 16.5 PSI it would go closer to 260WHP instead of the 249.xx your seen..
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Last edited by LatinVenom : 02-08-2008 at 06:34 PM.
Your prolly right about the exhaust.
But, thats the point of the exercise and most of the fun. We park a big airflow device on there and systematically remove bottlenecks until we get the ponies were looking for. Then we get to quantify the gains at each step.
Im running a .87 in the PE from 3500 on up. It's pulling about 9% fuel under boost so it may be a touch rich, But within the range of the WB.
I get no knock with the stock timing tables, havent looked for power in them yet.
Im running a .87 in the PE from 3500 on up. It's pulling about 9% fuel under boost so it may be a touch rich, But within the range of the WB.
I get no knock with the stock timing tables, havent looked for power in them yet.
Do you have any widebands hooked up right now? .87 is about 12.8:1 which is pretty good for LBT for the mid range stuff, might be a little lean for peak power... You're better off erring on the side of being too rich than too lean I would think, since peak power falls off faster on the lean side of LBT than it does on the rich side.
