Going from Race gas Dome to Pump gas. How much loss?

[speedfreek]

I have an ESR 310 with mid to top end porting. The head has the race gas dome in it. I am having problems buying/ traveling an hour just to buy race gas and I want to know how much difference will be felt or lossed swithcing to the pump gas dome.

Has anyone done this? And what can I expect? Thank you.

[quad janern]

I would like to know this too.

[hondamancbr03]

Macdizzy has a good read on HP change from compression only on dyno runs......If my memory is correct is was around 5 to 6 hp.

I can't recall what the change in compression that was made for the test.

[wilkin250r]

You'll loose a little in the midrange. The top end shouldn't lose much, and will also rev just a little higher, so it won't feel like you lose any at all on top.

High compression is a great low-end and midrange boost. Back in the day, the philosophy of engine building was porting and pipe to increase the top end, and high compression to bring back what you lost in the low end.

You'll need to be a little bit more aggressive with your shifting, with the loss of midrange power, you'll feel like you drop out of the powerband much faster.

[speedfreek]

Originally posted by wilkin250r
You'll loose a little in the midrange. The top end shouldn't lose much, and will also rev just a little higher, so it won't feel like you lose any at all on top.

High compression is a great low-end and midrange boost. Back in the day, the philosophy of engine building was porting and pipe to increase the top end, and high compression to bring back what you lost in the low end.

You'll need to be a little bit more aggressive with your shifting, with the loss of midrange power, you'll feel like you drop out of the powerband much faster. Thanks. This is what I was thinking. Looks like I might try it just to see. I may be able to hold it higher in the rpm's and that's where my bike runs best. It may be worth it!

[1promodfan]

Like wilkins said, most loss will be in the bottom to mid range. It won't feel like it has as much "grunt".

[hondamancbr03]

http://www.macdizzy.com/trx_dyno.htm

You really should do some light reading before making your decision....Depending on what you're currently at to where you are planning on going, you could see a 7hp lose at the high mid range and a 3.5hp at the top.

Compression creates HP across the entire range, any dyno chart will prove that...I'm suprised people would tell you otherwise.

I believe if you plan on owning and enjoying a sport such as atv's, reading and collecting as much information as possible is good practice.

[speedfreek]

Originally posted by hondamancbr03
http://www.macdizzy.com/trx_dyno.htm
. Thanks for the link. I have decided to leave in the race gas dome. I cant stand the thought of losing horsepower!

[hondamancbr03]

Originally posted by speedfreek
Thanks for the link. I have decided to leave in the race gas dome. I cant stand the thought of losing horsepower!

Amen brother!

If you think about the money we speed to get 2 to 5hp, giving up 3 to 7hp is a good size loss.

How much is race gas in your area?

[speedfreek]

Originally posted by hondamancbr03
Amen brother!

If you think about the money we speed to get 2 to 5hp, giving up 3 to 7hp is a good size loss.

How much is race gas in your area? I just bought 5 gallons of VP 110 for $48.15. That's $9.63 a gallon!! And this is not the oxygenated gas.

[CODY_M11]

I pay 80 for c12