I was talking to someone today about turbos and boost. He told me that if you run boost over 10PSI, you won't be able to run pump gas unless you severly retard the timing. Is this true? Cause then i have to wonder if i should build my motor when i get my swap. Cause if i can't run like 20lbs on, there might not be a point to doin it.

 

http://forums.evans-tuning.com/viewtopic.php?t=3046

http://forums.evans-tuning.com/viewtopic.php?t=2613

http://forums.evans-tuning.com/viewtopic.php?t=2859

http://forums.evans-tuning.com/viewtopic.php?t=2481




ALL ON PUMP GAS

 

Looks like you cleared that one up pretty quick. But i do have one question, every one of those engine seems to be running 9:1 compression pistons. That seems like a pretty high comp ratio since the low comp pistons i've seen are 8:1. But the highest boost was 15PSI on 93 octane, which is pretty good since the HP was in the 400s.

 

Yea, if you go to a good tuner they can make damn good power @ lower boost levels. Im going to take my car to Jeff Evans, and im hoping hell be able to make 200 whp with like 8-9 psi.

 

I was wondering about running two fuel systems. I would have my big tank that would store the pump gas, 93 octane when im driving around. Then i would have a fuel cell, maybe 5 gallons, that would be high octane race fuel (113 octane) for when i want to race. And there would a button or something that would switch the tanks as well as the boost and ignition timing settings.

 

Eh, thats kinda $$$ Sounding man. Most Engine Management Systems have 2 settings, 1 for street and one for track. So youd use the same tank, When you go to the track you switch settings and run race fuel, and vise versa for street driving.

 

The truck that im currently working on has two gas tanks. There is a switch in the cabin to switch from Tank A to Tank B. I haven't really looked into how this works since i have to fix the numourous leaks. But you said it has 2 settings. What if one setting was for 93 octane and the other was for 113 Octane and i some how got a switch that would pump the fuel cell fuel into the fuel system? It does sound complicated and expensive.

 

No point!? With a good tune and 20psi you're gonna be making crazy HP numbers, I doubt you'll be able to put that to the ground very well. A built motor and 12 psi would be plenty.

 

you ever look into water injection? That "effectively" increases the octane rating. water/methanol injection further effectively increases the octane rating. I run 11 psi on a roost style supercharger in my truck and have water/methanol injection at 5 psi. A turbo would be much better since it actually allows for the use of an intercooler so the pressurised air is cooler. The roots style starts creating more heat than power and thus less efficient at such high boost. Oh and around here all I have available at the pump is 91 not 93 like most places. So if you have access to 93, and intercooler and a good tune, you should be fine. If you want to go higher then look into water injection. Just a thought.

 

does your car have a knock sensor? if so your car can be tuned for max performance based partially off knock settings. 93 octane say at 20psi will have more detonation issues than 113 octane at 20psi. therefore the ecu will pull timing if need be according to knock readings. although a knock sensor can be added if you dont have one. tis one thing i hate about being obd0. my last set up was a stock y7 running 13 psi outta a 1st gen eclipse turbo......it was more than enough for what i wanted. but then again i currently just want a fun drive not so much alot of power. 200-250 bhp is more than enough to satisy my dd.