how to tune my 1st xp-t garret carb?

simbatheking said:

i just bought a used r&d turbokit with a 2871 turbo, a/f guage etc. My goal is to maintain 180hp at elevation on 91 octane non ethanol.

91 and turbo is no fun at all. My sled is 2860 and stock head and squish; I have to run extremely low boost to not hit knock sensor, under 6 lbs. I'd rather ride a big bore for that amount of boost. 2871 and head mods may allow for higher boost w/ out det., so you may be able to get away w/ it.

-how much do i increase boost with elevation?

I run 8 and up all the time so??? 8 down low. 12-13 up high. I don't really use elevation necessarily as complete guide to boost but more of a combination of snow conditions and clutching. I adjust boost to achieve rpm up or down and usually leave primary at clicker 3. If I want to run higher boost levels (bump overall hp), I clicker to 1 first and then adjust boost. Otherwise I think I should be running pretty steady hp numbers to the track most of the time.

-how much boost is needed to make 180 hp at 6k 7k 8k 9k 10k?

to many variables there, turbo size, charge temps etc.

-I ran my xp raves off exhaust pressure before, can i still do this with the turbo?

Do you mean something different then off the rave solenoids? Get pressure relief valve plumbed in w/ the solenoids and go. You won't have to wire or glue the bellows w/ the relief valve. I cheated and have mine after the solenoids w/out any issues. Some are putting before. Just a little more time/plumbing involved.

-what is a safe and optimal a/f ratio?

only have an egt so??

-what jetting should i use? it has carbs already set up with powervalves. and is jetted to run 10psi on 100ll.

Just as Visi said for jetting. My sled liked 5-6 base psi before running fuel pressure off pipe, 3-4 off pipe. Each seems a little different, so make sure you can fet to the regulator easily.

thanks

Click to expand...

simbatheking said:

i just bought a used r&d turbokit with a 2871 turbo, a/f guage etc. My goal is to maintain 180hp at elevation on 91 octane non ethanol.

91 and turbo is no fun at all. My sled is 2860 and stock head and squish; I have to run extremely low boost to not hit knock sensor, under 6 lbs. I'd rather ride a big bore for that amount of boost. 2871 and head mods may allow for higher boost w/ out det., so you may be able to get away w/ it.

-how much do i increase boost with elevation?

I run 8 and up all the time so??? 8 down low. 12-13 up high. I don't really use elevation necessarily as complete guide to boost but more of a combination of snow conditions and clutching. I adjust boost to achieve rpm up or down and usually leave primary at clicker 3. If I want to run higher boost levels (bump overall hp), I clicker to 1 first and then adjust boost. Otherwise I think I should be running pretty steady hp numbers to the track most of the time.

-how much boost is needed to make 180 hp at 6k 7k 8k 9k 10k?

to many variables there, turbo size, charge temps etc.

-I ran my xp raves off exhaust pressure before, can i still do this with the turbo?

Do you mean something different then off the rave solenoids? Get pressure relief valve plumbed in w/ the solenoids and go. You won't have to wire or glue the bellows w/ the relief valve. I cheated and have mine after the solenoids w/out any issues. Some are putting before. Just a little more time/plumbing involved.

-what is a safe and optimal a/f ratio?

only have an egt so??

-what jetting should i use? it has carbs already set up with powervalves. and is jetted to run 10psi on 100ll.

Just as Visi said for jetting. My sled liked 5-6 base psi before running fuel pressure off pipe, 3-4 off pipe. Each seems a little different, so make sure you can fet to the regulator easily.

thanks

Click to expand...

simbatheking said:

i just bought a used r&d turbokit with a 2871 turbo, a/f guage etc. My goal is to maintain 180hp at elevation on 91 octane non ethanol.

-how much do i increase boost with elevation?

-how much boost is needed to make 180 hp at 6k 7k 8k 9k 10k?

-I ran my xp raves off exhaust pressure before, can i still do this with the turbo?

-what is a safe and optimal a/f ratio?

-what jetting should i use? it has carbs already set up with powervalves. and is jetted to run 10psi on 100ll.

thanks

Click to expand...

swrev said:

Torgenrud,

another turbo XP in MT... Where are you at?

I used to have 390 mains in my turbo w/ out problems. Had powerjets off for most riding. Only opened them up for riding in my yard or if I knew I'd be doing some long pulls.

Click to expand...

Torgenrud said:

Hi there, Im new to snowest but I have some info that might be of use here, I built a carbed turbo xp this year but with an aerocharger turbo.
I ride anywhere from 5000 ft to 7500 ft

I run 3 psi of fuel pressure at idle with a rising regulator that goes up a pound of fuel pressure with every pound of boost.
My turbo is set at 8 pounds of boost with 95 octane fuel but I also have an RK tek turbo head
I have 400 jets which some people say is way to big but they work just perfect in my sled, my air fuel is at 13.5 which is a touch to rich but is better than to lean. optimal air fuel is 14.7.
You should easily get the 180 horse from 5 pounds of boost and should be able to run pump gas at any of those elevations.
I also run power jets in my carbs in case I need any extra fuel.
One way or another your going to love your turbo after you get all the bugs worked out.

Click to expand...