TSS turbo M8. What fuel to run with bikeman head?

[samsquatch47]

So I got a couple rides on my 2012 TSS M8 with the GTX2863 and love it so far except have a little pet peeve. I installed the bikeman turbo domes when the turbo was installed. Response at lower elevations at home (1800 feet) is wicked. Once up in the hills where I ride (usually 6-9000) the bottom end gets a little lazy and sluggish. I'm running 10 psi on straight 100LL AV gas right now. So is there a race fuel that would enable me to put the high alt non-turbo domes back in the bikeman head and have my high altitude response back? Of course I still would like to run the 10psi of boost and not detonate my motor.
Thanks for all replies

 

[Snowmow]

How's your air fuel ratio looking at 6000ft and above? Maybe your rich on The bottom when you get up there.

 

[samsquatch47]

Air fuels are great no rich spots at all. The Boost-it controller works great that way .

 

[Snowmow]

That's good.
Not sure what compression ratio the bikeman heads are. But I ran 100LL
At 10-11 psi on a stock 09 head. No problems.

 

[samsquatch47]

That's good.
Not sure what compression ratio the bikeman heads are. But I ran 100LL
At 10-11 psi on a stock 09 head. No problems.

Awesome that's great news

 

[samsquatch47]

Anyone else experiment with higher compression and boost at elevation?...

 

[w2bridin]

I run the 2010 ho head up to 10 psi at 900ft and 12 psi at 8000 ft on 100ll. But I did pull a little timing on the top. I have never tried lowering compression and raising timing but I would think that would hurt my bottom end?

 

[everytime5.9]

Do you regularly ride at those lower elevations? If not switch back to the stock head, it provides much better low/mid. Even if you have to turn the boost down a hair you will be around the same WOT hp. Should have some great snap with the 2863...

If you ride at those lower elevations and want to keep the lower compression head, Start weaning of straight avgas and mix some NON-ethanol 91 pump. You only need enough octane to suppress det, more isn't better and you will notice the difference in response. Hard part is just taking the time to figure out what your sled needs.

 

[samsquatch47]

I run the 2010 ho head up to 10 psi at 900ft and 12 psi at 8000 ft on 100ll. But I did pull a little timing on the top. I have never tried lowering compression and raising timing but I would think that would hurt my bottom end?

Good info man thanks! Yea I think the lower compression turbo domes are hurting the bottom end response.

 

[samsquatch47]

Do you regularly ride at those lower elevations? If not switch back to the stock head, it provides much better low/mid. Even if you have to turn the boost down a hair you will be around the same WOT hp. Should have some great snap with the 2863...

If you ride at those lower elevations and want to keep the lower compression head, Start weaning of straight avgas and mix some NON-ethanol 91 pump. You only need enough octane to suppress det, more isn't better and you will notice the difference in response. Hard part is just taking the time to figure out what your sled needs.

No I don't ride very often at lower elevations, if I do I could just turn the boost way down easily. The sled actually came with higher compression domes for the bikeman head so I could use them. I think those domes are real similar to the factory 800HO compression so I should be ok running straight av and 10psi at the higher elevations.
Thanks for all the feedback! Saves me wondering