Assuming one has enough fuel, how much boost can safley be run on pump gas, say 93-94 octane? I've heard only 15-16 psi, past that you risk detonation. Why would it detonate if you have enough fuel?

 

It's basically for the same reason you shouldn't run 15-16 PSI on 87 octane.

 

I have been running 18psi on 93 octane for a long time with no problems. My timing hasn't been retarded to make up for anything and my air/fuel was tuned to 11:5:1 on the dyno.

 

is 93 octane premium?
what the hell has 87? a voltswagon??
damn that is garbage...

 

Yeah, 93 is usually the highest you can get at a gas station here in the U.S. 87 is "regular."

 

I was running 17-18 PSI on 93 for 6 months, but I cracked my rear side housing with 20+ PSI. It was my fault because I added some more mods which raised my boost, but I didn't reprogram my boost controller.

 

I have a haltech. I recieved my base map from rotorsports racing, the car it came from was almost identical to mine, except he had a t-78 and I have a apexi rx6. I did the tuning myself at first, then when I took it to rotorsports we did some more fine tuning on the dyno, nothing major just tweaking fuel here and there. I actually had it tuned on the dyno for 15psi, then cranked the boost up later to 18psi. From 15psi to 18psi there is a big difference in power. I was dissapointed in my dyno results, which were 365rwhp and 352rwtq, but i'm sure with the added boost i'm around 400rwhp.

 

I ran 22psi with Haltech E6K and made 500rwhp on pump fuel

 

I run 15 psi on 89 octane.

BUT I have lower compression rotor and Matt tuned my E6K also.

 

How about 91 octane? I'll be moving to CA soon in an area where 91 is normally what you'd find.

how much boost can I run with say a T04E and a goal of 400 WHP? it would have to be tuned more for safety rather than all out power.

any input?

TIA

 

yep it sucks..i havent seen one place that had more than 91 octane

 

Yeah, to add to this, how much boost can I run my '89 T2 with stock injectors and an FCD? Safely. And also, what will the max be on 91 Octane gas? What about 87 and 89? Can anyone explain what limits the boost in relation to the octane? Seems to me it would be heat limited (more boost, higher heat) but then wouldn't a different intercooler alter this? Possibly be more like "How much boost can I run on a stock intercooler?" I dunno, I'm just thinking outloud...

 

If you just have an FCD and no other fuel mods then you really shouldn't go over 10 PSI. If you get a good FMIC and some sort of fuel computer then 12-14 PSI should be ok, depending on how good your motor is.

 

If he ups the power, then the amount of boost he can run will decrease. 2nd Gen injectors are good for about 14psi in standard form. Up the power and it decreases quite rapidly.

I don't run 22psi on the street, but am able to run up to 19psi safely. HITman says we could have got 25psi on pump fuel but the likely hood of the engine never idling again were greatly increased

Oh, BTW, we have 98RON pump fuel in Australia