Thanks guys. I have heard of many stories of people pulling the plug on a design like this due to the complexities. This is why I first spoke of this in March then made everyone wait till mid May for a result..lol.

We could have a retarded long discussion on boost level effects from altitude. I will only hit a few points.

Yes, 8psi is 8psi. That is you will have 8pounds of pressure in a given volume. But the "mass" of that air is different. There is also less oxygen at elevation, everyone knows that. There are hundreds of sites that state a Supercharger will lose psi as altitude increases. Even right in the stillen kits manual when troubleshooting for having low boost levels....1. Belt slippage, 2. High elevation. I doubt they would put a claim in there for that if it werent true.

There is a thread on this forum that a guy with a turbo Z placed his 2 dyno graphs on here. In the first he was in L.A. and the second was after he moved to Denver. He lost something like 80whp after bringing the car here. If his car was NA he wouldnt have went from 230whp to 150whp. So the boost of the vehicle was not putting down as much power.

 

^^^ I agree, I'm not trying to turn it into a SAE/Boost as related to altitude either. I was more so saying that wastegates will open at the spring pressure(8lbs for example) no matter the altitude. I would be curiuos as to how the turbos are coming on boost wise by themselves. If the supercharger is building a few lbs of boost before the turbos are, it might be cracking the wastgates slightly causing the boost to be laggier then it could be. I think for testing purposes I would only change one thing at a time, either the supercharger pulley or the wastegate springs and measure the boost in the compressor housings.

 

Yeah I hate to admit it but never really thought of the wg opening prematurely due to boost detection. Hmmmm....

So anyway while were touching on elevation still. Would I be safe to run uncorrected #'s in the high 400's here then?

 

Where is your waste gate signal from?

 

You are correct. I was looking at it from the CFM flow side which is calculated assuming one atmosphere of inlet pressure. Now we would be calculating lb/hr rather than CFM since we changed the constant.

 

Change that WG reference location before anything else... should breath some life into the top end.

 

I've got a cheap red box for sale, pm me if you are interested.

 

def change the waste gate reference and dyno it again like others have said it could def be seeing some of the boost from the supercharger and opening the wastegate too soon, especially with such a weak spring it is going to be very sensitive.

 

^^ OP confirmed by email the WG is referenced at the compressor housing so that isn't an issue. I guess we misread or he misspoke.

 

wouldnt mind seeing this when he decides to get aggressive with it, looks like it is sorta working, might really show up with a more conservative tune and more boost *shrug*

 

Turning it up is going to make more heat as well. I would consider water/meth injection also.

 

turning up the boost dosnt always mean more heat, looking at the efficiency island of the gt35, he could probably turn the turbo up to 6 or mayby 7 psi without touching the heat generated due to greater efficiency. but yah meth would be awesome but i would throw that in with more aggressive tune and boost.