to lower compression or not to?

[FLYBYU]

I pretty much 80% of the time ride trails, but there is some long straight aways in the u.p. I have a friend that has his lowered his and running more boost like 18 lbs on trail. Says i don't need that much on trail which i do agree on. I'm running like 10.5 lbs on stock compression and no stacked headgaskets. He says its not safe. So my question to do it, lower compression and stack gaskets or run it like it is. I just want that safe state of mind when im 200 miles from our cabin. It's on a 07 apex with a cpr frount mount.

 

[lakercr]

I pretty much 80% of the time ride trails, but there is some long straight aways in the u.p. I have a friend that has his lowered his and running more boost like 18 lbs on trail. Says i don't need that much on trail which i do agree on. I'm running like 10.5 lbs on stock compression and no stacked headgaskets. He says its not safe. So my question to do it, lower compression and stack gaskets or run it like it is. I just want that safe state of mind when im 200 miles from our cabin. It's on a 07 apex with a cpr frount mount.

If you were my customer my first suggestion would be to run better fuel. The "200 miles from my cabin" part suggests this is not an option. I'd add the gaskets or do LC pistons if you plan to consistantly run that level of boost.

 

[FLYBYU]

which way is better?

 

[Remmy]

Pistons are the way to go if you want to do it right.

 

[Ted Jannetty]

I pretty much 80% of the time ride trails, but there is some long straight aways in the u.p. I have a friend that has his lowered his and running more boost like 18 lbs on trail. Says i don't need that much on trail which i do agree on. I'm running like 10.5 lbs on stock compression and no stacked headgaskets. He says its not safe. So my question to do it, lower compression and stack gaskets or run it like it is. I just want that safe state of mind when im 200 miles from our cabin. It's on a 07 apex with a cpr frount mount.

10.5 PSI on pump fuel is Dancing on the Landmines.

Stack 3 head gaskets and do it before it is too late.

Ted.

 

[TWIN TURBO]

Pistons are best but alittle painful time/money.

 

[KnappAttack]

If it were mine, I would lower the boost down to 8 lbs. I had three stalked gaskets last year on 12 lbs. of boost and you couldn't stay into the throttle for any length of time unless you were out on the lake. I believe the 270 HP I had was too much for trail usage. If I had to do again I would tq stock head and gaskets to Teds spec and run the CPR at 7.5-8 lbs of boost. 235-240 HP is as much or more than these tracks can take. I blew one out on the lake @ 135 MPH on my old CPR 200 HP RX-1 and it wisened me up a bit!

 

[canuck5]

According to what I have plugged into the octane calculator if your running stock compression you should be running some high octane fuel @ 10.5psi. Depending on elevation looks like octane should be in the high 90's

 

[FLYBYU]

i think im going to go with the stacked gaskets the next question is where to buy

 

[kinger]

Why go through that hassle? I mean go 7psi and call it a day. Your not lake racing and the sled is plenty fast at that boost. Your talking a difference of maybe 30hp? That 30 hp is the difference between a complete teardown, and reassembly, enter murphys law and I would expect you might not have a great season.

If it were me all stock at 7 psi and go like heck!

 

[mulot30th]

You will never ever see 230hp at 8 psi.

 

[woodsrider]

For what it's worth, I'd consider leaving the motor stock and buy better fuel. With the price of super unleaded in my neck of the woods race fuel isn't that much more money. Unless you're putting a ton of miles on it's only the cost of a movie for the weekend and you have the higher hp.

 

[1xr]

I am in the process of getting a cpr kit for my buddys apex. I'm hopeing he will not have any trouble with detenation. Premium pump gas here is only 91 I wish it was 93. About half where this guy rides is in locations where only 87 gas is available. He drives his stuff like he stloe it. I may have to hook up a high low boost controler and take it down to may 6lbs? or so. Does anyone else have been force to run 87 gas from time to time?

 

[Sapling]

Hell with my boost controller all the way down I can only get down to 12 pounds.

Sap

 

[powderlites]

boost controler

Take apart boost controler and shorten the spring! Bench test and some are over 11 psi
http://www.powderlites.com