Setting up a engine for pump gas boost - playing with calc

[kinger]

Just playing with the calculator and trying to figure out what a TRAIL pump gas SC would put out for power with the octane limited. I did it again last trip got out of gas in BFE and pulled up to the only pump in 30 miles and it was 87 octane only.

Here are some scenarios what would you do?

9:1 pistons
10.7 boost MPI pulley 26/22
octane needed is 88.3
hp is 240hp

10:1 pistons
7.9 psi
octane is 89.2
HP is 217

3 head gaskets
7.9 psi
octane is 90.3
HP is 218

9:1 is the most power with the most saftey as a octane booster would get me to that 88 if all I had was 87 right? Now spreadsheets are fun but people that run in the REAL world how close am I? With the MPI building boost at clutch engagement do i care about 9:1 vs 10:1? Still no lag more safety and more power make sense to those running that?

Thanks!

 

[Ted Jannetty]

Re: Setting up a engine for pump gas boost - playing with ca

Just playing with the calculator and trying to figure out what a TRAIL pump gas SC would put out for power with the octane limited. I did it again last trip got out of gas in BFE and pulled up to the only pump in 30 miles and it was 87 octane only.

Here are some scenarios what would you do?

9:1 pistons
10.7 boost MPI pulley 26/22
octane needed is 88.3
hp is 240hp

10:1 pistons
7.9 psi
octane is 89.2
HP is 217

3 head gaskets
7.9 psi
octane is 90.3
HP is 218

9:1 is the most power with the most saftey as a octane booster would get me to that 88 if all I had was 87 right? Now spreadsheets are fun but people that run in the REAL world how close am I? With the MPI building boost at clutch engagement do i care about 9:1 vs 10:1? Still no lag more safety and more power make sense to those running that?

Thanks!

The Problem with the calculator is, it is only a guide it is not rock solid, there are To many factors that play in to detonation, outside air temp, intercooler efficiency, actual air temp at intake valve, humidity, water temp, air fuel ratio, exhaust flow, cam timing, engine load dictated by rider weight, snow conditions and clutching, Gearing, and I am sure there are a few others.

9:1 will also deliver the worst fuel economy, and poorest throttle response boost for boost throttle position for throttle position.

You don't have the luxury of advancing the timing in off boost situations to make up for the lost cylinder pressure.

I like the stock engine with 6 PSI boost and call it a day especially if you go long distances trail riding.

Second choice would be 2 head gaskets with 8 psi boost.

Your like every other Human we want it all, but there are mechanical limitations we just have to accept.

Ted.

 

[kinger]

Thanks Ted, this is what I'm looking for is real world experiences in reguards to tuning, mpg, etc. I like that you offer your favorite options that helps. Thanks!

 

[Skydog]

I know this is nuts but 2,500miles 9psi of boost on pump stock motor. And 2,490miles with no BOV or the cold air kit. The I.C. used to get so hot i have no idea how this sled did not deto! Now with the BOV and cold air kit the IC is cold to touch. So i feel i will be good to go now!!!! Time will tell....

Skydog

 

[kinger]

That thing must be a rocket at 9 psi on stock compression!

 

[Skydog]

Buddy for real!! 0-100MPH she ROLLLSSS HAHA Plus with the RB3 we gave her a good (+2-3 deg) of timming down low!!HAHA But we did pull out some on the big end too. (-2-3degs)

Skydog

 

[gsxr]

My ride is a 2007 rtx sc 136x1.5 @ 5 lbs with Teds bov .

As safe as can be for travelling !

Having a rr tank built as we speek to go on the tunnel extention , will vent feed to front tank . Adds 25 miles on a fill up !

 

[lakercr]

I know this is nuts but 2,500miles 9psi of boost on pump stock motor. And 2,490miles with no BOV or the cold air kit. The I.C. used to get so hot i have no idea how this sled did not deto! Now with the BOV and cold air kit the IC is cold to touch. So i feel i will be good to go now!!!! Time will tell....

Skydog

Kids, do not try this at home.

 

[Skydog]

I know this is nuts but 2,500miles 9psi of boost on pump stock motor. And 2,490miles with no BOV or the cold air kit. The I.C. used to get so hot i have no idea how this sled did not deto! Now with the BOV and cold air kit the IC is cold to touch. So i feel i will be good to go now!!!! Time will tell....

Skydog

Kids, do not try this at home.

HAHAHAHA