How much boost do y'all think you could push (turbo) and still maintain the stock rev limiter with stock internals? My guess would be 6-8psi before you'd want to with stronger valve springs retainers rods. Any opinions?

 

a number of people with the SpeedCraft turbo kit have boosted 10+ psi on race gas (104 octane?) with no trouble. All without internal work. derryck, who was the first person with the kit, ran 8 psi (if I recall correctly) for thousands of miles without a hitch. You can PM him for details.

Matt

 

[QUOTE]Originally posted by azrael
[B]a number of people with the SpeedCraft turbo kit have boosted 10+ psi on race gas (104 octane?) with no trouble.

 

[QUOTE]Originally posted by Babyjoy
[B]And still revving to 9k rpm?

 

Do a search, at least a 50% mortality rate using turbos on stock internals. More than likely those who've blow their engines have dialed up the boost. Personally, I think 4-6lbs of intercooled boost is the limit on stock internals for any extended period of time. Chris in the link above was using a lower compression gasket to try and tame things a bit, but from what he has disclosed to the general public... well click the link.

 

I believe that 1Randyc was planning on lowering the redline for his setup with Comptech supercharger/intercooler/smaller pully.

Ted

 

[QUOTE]Originally posted by jerrypeterson
[B]Do a search, at least a 50% mortality rate using turbos on stock internals.

 

There's been a LOT of discussion on these issues already, which you can find pretty easily using the advanced search feature on the board.

The fact is, however, that there's precious little evidence on which to base any meaingful conclusions. In each case, the "mortality" issues to which some of you have alluded are attributable to specific circumstances that go beyond the question of maximum boost. For now, at least, there just aren't many of us out there.

Speedcraft's default setting for high boost is just over 8psi, but that's based on their experience with earlier Honda engines and a degree of conservatism. Nobody really knows, and it's folks like ChrisD (who's been consistently running 10-11 psi of boost on a stock engined) who are the test rabbits for the rest of us. Be grateful to them.

My sense, for what it's worth, is that it's not the engine that's the binding constraint, once you go beyond 10psi of boost, but other elements of the powertrain. Our car just wasn't built for high-rpm clutch drops.

 

I tried to be open about everything I have done and I got beat up for it so I decided to stop talking about it. No one has been crying since.

The redline and the boost level are completely seperate and somewhat unrelated. I am not sure what you're getting at here, how to run a stock F20C with out a problem? Run at 6 psi, or 8 psi with race fuel. Based on the results shown thus far it seems to work well. The Vortech unit will be running at 8 psi with ignition retard, they have been testing it for about a year now.

If you wanna run more boost then you're in the experimental zone, avoid detonation and you should be fine for a while. The pistons appear to be a very solid construction, the rods are questionable. Sleeves will hold up to 11 psi at 11:1 compression, but who knows for how long?

The bottom line is anything above 6-8 psi is unknown.

Have fun.

Chris

 

We need to cut Chris a break about how he's handled the head gasket on the boards. This issue keeps coming up, and it's stale.

Let's respect the man for his position and let it go.