Need help with tire calculation for MPH
Thread Starter
Race Director
Joined: Nov 2000
Posts: 11,221
Likes: 899
From: CA
2017 C5 of the Year Finalist
St. Jude Donor '08
Need help with tire calculation for MPH
I know there is a formula out there, but can someone give me the EXACT difference in MPH between the following tires. I have a Quaife 373 dif with a built RPM M6 tranny with G-force 5th and 6th gears.
I now run a Nitto NT-01 315/30/18 tire, and want to know what my actual MPH will be at 6600 RPM in 6th with this tire, and then with a Toyo R888 305/35/18 at the same gear and RPM.
I've seen my Speedo hit 199 MPH in 6th at 6600 RPM with the nittos before, but don't believe that was quite accurate.
I'll be heading out to the runway next month, and would like to kiss 200 on radar...
Thanks in advance for the help!!
JB
I now run a Nitto NT-01 315/30/18 tire, and want to know what my actual MPH will be at 6600 RPM in 6th with this tire, and then with a Toyo R888 305/35/18 at the same gear and RPM.
I've seen my Speedo hit 199 MPH in 6th at 6600 RPM with the nittos before, but don't believe that was quite accurate.
I'll be heading out to the runway next month, and would like to kiss 200 on radar...
Thanks in advance for the help!!
JB
Tech Contributor
Joined: Apr 2007
Posts: 10,924
Likes: 77
From: Forney Texas
I'm assuming you have the .70 6th gear from G-Force.
If that is the case, not accounting for any tire height expansion at high speeds, you need to achieve 6670rpm to hit 200mph on the Toyo's and 6925rpm for the Nitto's.
I show the Toyos are 26.3" and Nittos are 25.35" tall.
Speaking of running the mile, did you hear about the latest official record set by Ray Hoffman of Midland TX in his 1900RWHP Heffner GT? 266.9 going straight into a 18mph headwind.
This stuff's gotten crazy!
Good luck bro!
If that is the case, not accounting for any tire height expansion at high speeds, you need to achieve 6670rpm to hit 200mph on the Toyo's and 6925rpm for the Nitto's.
I show the Toyos are 26.3" and Nittos are 25.35" tall.
Speaking of running the mile, did you hear about the latest official record set by Ray Hoffman of Midland TX in his 1900RWHP Heffner GT? 266.9 going straight into a 18mph headwind.
This stuff's gotten crazy!
Good luck bro!
Thread Starter
Race Director
Joined: Nov 2000
Posts: 11,221
Likes: 899
From: CA
2017 C5 of the Year Finalist
St. Jude Donor '08
I'm assuming you have the .70 6th gear from G-Force.
If that is the case, not accounting for any tire height expansion at high speeds, you need to achieve 6670rpm to hit 200mph on the Toyo's and 6925rpm for the Nitto's.
I show the Toyos are 26.3" and Nittos are 25.35" tall.
Speaking of running the mile, did you hear about the latest official record set by Ray Hoffman of Midland TX in his 1900RWHP Heffner GT? 266.9 going straight into a 18mph headwind.
This stuff's gotten crazy!
Good luck bro!
If that is the case, not accounting for any tire height expansion at high speeds, you need to achieve 6670rpm to hit 200mph on the Toyo's and 6925rpm for the Nitto's.
I show the Toyos are 26.3" and Nittos are 25.35" tall.
Speaking of running the mile, did you hear about the latest official record set by Ray Hoffman of Midland TX in his 1900RWHP Heffner GT? 266.9 going straight into a 18mph headwind.
This stuff's gotten crazy!
Good luck bro!
I saw that Crazy GT, I'd just be happy to touch 200, don't need to go beyond it.
Thanks again!
Tech Contributor
Joined: Apr 2007
Posts: 10,924
Likes: 77
From: Forney Texas
I don't remember your power level, but close 800rwhp is what it takes with all the other variables in line such as wind. I am wanting to go out there one day and see what mine does. There's a lot of difference between beating on a car through a few gears and for an entire mile and that kinda worries me, but I think I'm going to have to find out.
Melting Slicks
Joined: Aug 2002
Posts: 3,295
Likes: 40
From: East Coast fl
You'd need to know exact trans gear ratio to be sure.
Standingmile:This is the funnest form of straightline racing I have ever done. It's a blast. Nothing like 3/4 5th gear pull. Get your fueling right for sure.
Standingmile:This is the funnest form of straightline racing I have ever done. It's a blast. Nothing like 3/4 5th gear pull. Get your fueling right for sure.
Thread Starter
Race Director
Joined: Nov 2000
Posts: 11,221
Likes: 899
From: CA
2017 C5 of the Year Finalist
St. Jude Donor '08
I don't remember your power level, but close 800rwhp is what it takes with all the other variables in line such as wind. I am wanting to go out there one day and see what mine does. There's a lot of difference between beating on a car through a few gears and for an entire mile and that kinda worries me, but I think I'm going to have to find out.
You are right, making a quick rip to 140 or 150, vs WOT for one mile to 200 MPH are two very different things, although I'm more concerned about running out of gear before I get to the end of the mile, then not hitting 200.
Thread Starter
Race Director
Joined: Nov 2000
Posts: 11,221
Likes: 899
From: CA
2017 C5 of the Year Finalist
St. Jude Donor '08
I run an Areomotive Eliminator pump with their new fuel pump controller (it works off a progressive RPM ramp that allows you to lower volts to the pump under lighter throttle, so as not to churn up/overheat fuel) with a custom duel tank feed. The FPR then returns to a Cooler mounted up front before it dumps back into both tanks...
Melting Slicks
Joined: Aug 2002
Posts: 3,295
Likes: 40
From: East Coast fl
I run an Areomotive Eliminator pump with their new fuel pump controller (it works off a progressive RPM ramp that allows you to lower volts to the pump under lighter throttle, so as not to churn up/overheat fuel) with a custom duel tank feed. The FPR then returns to a Cooler mounted up front before it dumps back into both tanks...
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St. Jude Donor '08
