Hi comp pistons

[Dave s]

Does anyone no if there are any of the shelf high comp pistons?

[Motion Lab]

Dave,

All of the Wiseco made pistons are a 9:1CR. Having said that they should have all the measurements to make a high compression version if you request. GTM also has stock compression Arias pistons available I believe.

Why are you looking to go higher than 11:1? Whats your overall goals?

Thanks,
Alex Goodwin
AlexG@motionlabtuning.com

[synolimit]

Power!

[Motion Lab]

Originally Posted by synolimit

Power!

What is the intended fuel?? That is a major consideration when choosing compression ratio.

Thanks,
Alex Goodwin
AlexG@motionlabtuning.com

[G37sHKS]

11 is not enough nowadays?

[synolimit]

Originally Posted by Motion Lab

What is the intended fuel?? That is a major consideration when choosing compression ratio.

Thanks,
Alex Goodwin
AlexG@motionlabtuning.com

Most will do 93. Race bikes are all 12+ and can run regular fuel. I know it's a different machine since 600's rev to 16,000 rpm.

The question is what gets more power? If you go 12+ and have to back the timing out will you have the same power as if you left it stock with more timing? At least have two maps, one with e85, race fuel, or if that torco works and then regular fuel.

[canes7]

So lets look at things a bit differently. Power (HP) is a calculation of torque X RPM / 5252. As I understand it higher compression ratios move the torque curve up on the RPM scale, not necessarily making more torque but more HP just by calculation. The VQ37 engine already makes it's peak power @ 7000 rpm.

So how fast do you want to spin this engine??? I come from the old school so 7k seems like a lot to me already. Can these engines handle 7k or 8k regularly?

[phunk]

Originally Posted by canes7

So lets look at things a bit differently. Power (HP) is a calculation of torque X RPM / 5252. As I understand it higher compression ratios move the torque curve up on the RPM scale, not necessarily making more torque but more HP just by calculation. The VQ37 engine already makes it's peak power @ 7000 rpm.

So how fast do you want to spin this engine??? I come from the old school so 7k seems like a lot to me already. Can these engines handle 7k or 8k regularly?

Higher compression has nothing to do with RPM.

[phunk]

Originally Posted by synolimit

Most will do 93. Race bikes are all 12+ and can run regular fuel. I know it's a different machine since 600's rev to 16,000 rpm.

The question is what gets more power? If you go 12+ and have to back the timing out will you have the same power as if you left it stock with more timing? At least have two maps, one with e85, race fuel, or if that torco works and then regular fuel.

without racing fuel/e85, I dont think I would feel comfortable going over 11.5 or 11.7 to 1. Generally a street engine that goes higher than 12:1 is using direct injection and or cylinder pressure monitoring.

[canes7]

Originally Posted by phunk

Higher compression has nothing to do with RPM.

Please elaborate.

[Chuck33079]

Originally Posted by canes7

Please elaborate.

My guess would be that the static compression ratio is the same whether the car is idling at 750 rpm or at redline.

[synolimit]

Originally Posted by canes7

Please elaborate.

I'm no expert but compression is power, it has nothing to do with rpm. If you cram air and fuel into a space and ignite it, it goes boom. If you cram the same amount into a smaller space (more compression) you get a bigger boom. The more faster bigger booms you get from 2-7k, the more power you make. Hp is basically just a guess calculation from how fast you can get a drum to spin from beginning to end in xxx amount of time. TQ obviously is a measure of the force on that drum.

Now with degreeing the cams, cam tuning/timing, ignition maps etc, you can put the added power where you kinda want it. My race bike for example made about 12 hp from a thinner head gasket. That power started in the mid range from 6-10k. But since you're never really that low, we degreed the cams and moved it above 10k where it was needed more.

[canes7]

Originally Posted by Chuck33079

My guess would be that the static compression ratio is the same whether the car is idling at 750 rpm or at redline.

All the articles I can find quickly focus specifically on how efficiency is increased by upping the CR. I was referring to CR's effect on the torque curve. If I find something I'll post it.

[MyKindaGuise]

13:1?
GTM Motorsports*::*ENGINE INTERNALS*::*Pistons*::*GTM / Wiseco VQ Extreme Duty Lightwieght Pistons

[synolimit]

Pretty