KStromberg
Dedicated LVC Member
Everyone says how they want to spin these motors higher and higher but has anyone even had theirs on the dyno up to 7000-7500 rpm? Does it make any power up to that point?
No, my car does not make power up to 7K rpms, but that does not matter in terms of acceleration. With these cars shifting PAST peak power is optimal. It all depends strictly upon setup with how far you go before you shift.
Here, I'll attempt to explain:
With my commanded shift points now near 7K rpms, the car is picking back up at approximately 5000 rpms into the next gear. That is pretty much perfect because that is on the windward side of the tq/hp "mountain" on my graph. I am building torque into the next gear by starting at the side of the mountain and peaking hp throughout the gear rather than starting off the next gear over in the field 2 miles away and having to travel all the way through the flat field before I reach the mountain and start climbing again. Staying in the sweet spot on the curve when you begin the next gear is going to provide maximum acceleration which is why you shift past peak power. If you shift at peak power however, you have a whole lot of ground to make up on the next gear, and as a result, you will run slower times.
A perfect example of my theory proven true was last year on the chip tune. I made my first two passes letting the tune shift the car at 6200 rpms in 1st and 6400 rpms in second. I ran a couple low-14 second passes. I then said screw this crap, it's obvious the car needs more rpms so my only choice was to manually shift the car. So I held out the gears. I did that a few times bouncing the rev limiter and then finally getting it down to some good passes without hitting the limiter and wa-lah, I started running 13 second passes and my trap speeds were up 2-3 mph.
So needless to say, after that adventure I inquired of DLF to get some input on where he is shifting. Sure enough, he is up there right at about 6900 rpms shift points. When I got it on the dyno, I told the operator, "do that" LOL The car feels even faster than 13.59 now, so I think I went the right direction.
So anyhow, if anyone knows these cars especially tuning-wise, DLF is one of them. I will quote him here: "7000 rpms was a bit too much and 6800 rpms was not enough". I'll go with what this guy says, especially considering I don't have a doubt in my mind he will have the fastest all motor Mark8 before the year's end.