I know there are some programs to calculate this all but just need a bit of info regarding et/mph/rpm change seen in when downsizing.

In general i believe the et's should come down, mph as well, but rpm's on the top should come up some but roughly how much for each?

Currently running a 26" Hoosier QTP on an evo9 trans w/ evo8 4th crossing the traps at 8200 rpm but was wondering what i can expect to see if i were to switch to a smaller diameter tire say a 24".

Thanks

 

I wouldnt want to go with a smaller tire...the 26's and the ones to have IMO. All your gonna do is cut the gear ratio down and you'll be going throught the traps at a higher rpm. and have to shift again, depending on how high you want to rev it.

 

Figuring with the 26" tire and 3.73 gear ratio (unsure of gear ratio)
170.11 mph

With the 24" tire an 3.73 gear ratio
157.03 mph

Those are the MPH where you will run out of gear. I just got done with that class last session so if you need and of the formulas, just let me know and ill send them to you. They are fairly easy to figure out.

 

quicker et slower mph

 

Thanks Brian.......do you happen to know approx hom many more rpm's you turn crossing the line vs the 26" tire?

 

Not exactly, but I know I lost 2 mph. I believe the rpm increase was a few hundred. I dont datalog, so cant give you eact numbers. It was worth it for what I was trying to do. The differences were noticeable...

 

have fun shifting into 5th

 

Nobody shifts to 5th and look at his set up. Mike at AWD went 8's @ mid 150 mph on a 24' tire. These built motors will turn 9500

 

I shift to 5th.

 

Shifting to 5th will kill your ET and MPH period. I have run everyone of my evo's on stock valvetrain to mid 8k without one issue. Now that I have a built valvetrain mid 9k rpms are no problem. This info is based on evo 8's 4th gear. Anyways, a 5th gear shift is suicide....

 

I know, when i took the 35r setup out I was still on the stock evo 9 trans. I wasent gonna spin the stock engine to 12k.

Fathouse

 

Poo-c.