saving Stock rods by keeping peak torque low ?
#21
I made 280 whp with a holset hy35 on a stock BP until the oil pump blew. another guy on clubprotege made 300hp on a stock BP. he had an aem stinger with a good tune that motor lasted for two years and then the oil pump gears shattered. I could probably list a dozen who have been around 300whp with stock internals granted some of them didn't last that long. its all in the tune.
Im planning to run a stock flywheel with a FM clutch. With all the vibrations that are going on at the crank with 250whp using a light weight flywheel seems like a bad idea
#28
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There have been a few GT2560's on stock bottom ends making around 300hp reliably throughout the years. Saint_Foo was also pushing right around that much on his setup, and I know he beat the **** out of it. One thing is that just about every gt2560 making that sort of power is on an absurdflow setup.
#29
So when it comes time that I start tuning the spark am I correct in my thinking that the way to tell if my timing is too far retarded would be
1. get an EGT probe and watch for high temps (which I havent really planned to use on my setup)
2. Watch the AFRs and see if they start going richer
1. get an EGT probe and watch for high temps (which I havent really planned to use on my setup)
2. Watch the AFRs and see if they start going richer
#33
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Resurrection.
Conservative tune, stock engine, '99. Concern is rods, just like this thread.
Can I run 200- 210 Ft-Lbs torque safely as low as 3500 RPM, if the mini-turbo can make it? Right now I'm hitting it at about 4000, same as Karter74 did.
Conservative tune, stock engine, '99. Concern is rods, just like this thread.
Can I run 200- 210 Ft-Lbs torque safely as low as 3500 RPM, if the mini-turbo can make it? Right now I'm hitting it at about 4000, same as Karter74 did.
#36
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I would theorize that the RPM doesn't matter, but the ignition timing matters a great deal. Lots of ignition timing = tons of peak cylinder pressure. In order to get big torque from a turbo before the cams are in their sweet spot, people typically pile in the timing, which bends rods. Keep the timing soft and you can probably make 220wtq at 3000rpm on a stock motor if you want to.
#38
It's a combo of both, less air and fuel in the cylinder sparked closer to MBT will make the same power as more air/fuel sparked later in the cycle. I like to spark the mix earlier in the cycle with a rich mixture, helps to dampen that cylinder pressure spike and keep an even pressure on the piston through out the cycle.
To your point timing is very important but it gets to be a lot easier to control with less boost pressure.
To your point timing is very important but it gets to be a lot easier to control with less boost pressure.
#39
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Honestly, I've heard a compelling argument that you can run even more torque in the top end because the force is applied for a smaller period of time when rpm is highest. But I still stick with 220ftlb and make certain the timing is very soft in the 3000-4500rpm range.