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Discussion Starter #1
Anyone have a built 2.5 racing circle track? Having trouble with gear/tire size to keep it under 8000 RPM. Is it ok to run 82-8400 briefly? Anyone doing it regularly?
 

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You looking for rpm or grunt? I wouldn't want to turn a long stroke motor as a 25 at that rpm.....A 20 is possibly what your looking for.....
 

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Discussion Starter #5
Do you/have you raced one at that RPM? Cams are available to 8500 redline. Im getting mixed info which is why Im asking for people with experience racing one.
 

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Tri-Point engineering had Comptech build a few 25's for a few of their race cars (Mazda 3's). 270hp at 7800 w/ 220 lbs of grunt at 6400 hooked to a Xtrac 6-spd sequential box. Tri-point has a lot of history dealing w/ mzr motors as well as Mazda's.....Cams can rev to whatever, doesn't mean the motor will last.....
 

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Discussion Starter #7
Yes. I agree. Again though, did they turn it past 8000? Im stuck with available tire size/gear selection without buying a $5-8000 custom transaxle.

Im asking for anyone who has ACTUALLY turned it past 8000 and their EXPERIENCE.
 

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I have a couple that turn the 2.5 in the 7400-7600 range over 210hp to the wheels

When you say built what are you talking about ?

Tom
 

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Discussion Starter #9
Sigh... Ok by built it has a Ford Ranger crank with a keyed cam chain sprocket. Molinar Rods, pistons, rings bearings, ARP main and rod bolts. ARP head studs, Crane springs, retainers and cams. 12.5:1 compression. stock Escape intake, K&N Intake tube and filter, OBX header. It has the balance shaft delete, egr delete and VVT delete.
It made 211 hp on chassis dyno after tuning.

What I would like to know Tom, is HOW is your customer only turning 7800 RPM? That would be great! because this beast on a 1/4mile highbanked asphalt circle track hit the rev limit of 8000 before the end of the straitaway using the tallest Hoosier tire we can run using a 3.42 trans in second gear... Then motor shuts off and you have to cycle the ignition to restart it. In the corner....
 
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