I have been searching trying to figure out which JDM ITR transmission I have. I bought some turbos and 2 transmissions from my step-brother for $200. One was a b16 tranny off his del sol vtec. The other was a ITR transmission he had imported a few years ago. I have a gsr swap I did about a year ago and just threw in the ITR transmission but I can't figure out which one it is since so many have s80 on the casings.

From what I have read. Gsr's run 4,000 rpms at 80 mph. It appears 96-97 ITR's run at 4,800 rpms at 80mph and 5,000 rpms with a swapped out 4.7 fd. What does a 98+ spec ITR transmission run rpm wise at 80 mph??? Mine is running at 4,500 rpms at 80 so I am wondering if I might have lucked out and got a 98+ spec.

 

My guess would be your cluster/tach is off a few hundred rpm or your wheel tire size is making custer be off. and you prob have 96-97 itr 4.4fd

 

I forgt to mention I am getting my rpms from a autometer tach and my speed from my double din GPS.

 

http://teammfactory.com/gear-calculator

 

I do not understand you everyone says tire size matters. the VSS runs straight off the differential, BEFORE the tires. so your tach and MPH should always be accurate, but you maybe be going faster, slower then it says. But if you run 80 at XXXX rpm with a big tire, you will still run 80mph at the same RMP, whether the car is actually going 80mph or not.

 

This is true!!! Tire size is irrelevant when it comes to what the gauges should read.

I went ahead and calculated the top speeds for each gear for the gsr, Usdm ITR, and 98+ JDM ITR transmissions.

GSR



USDM ITR


JDM ITR



Now to go top out 3rd and see what speed I am at.... Or just reduce the redline limit in the calculator to show speed at 80.

 

at 62 in my 4.7, I'm at 34-35ish I do believe.

 

At 4000rpm's, a GSR should be doing 79mph.
At 4400rpm's a USDM ITR should be doing 81mph.
At 4400rpm's a JDM ITR should be doing 80mph.

So much for that thought process!!!

Thanks Doood for the resources to figure out my answer!!! Guess the only way to truly know is to count teeth on FD. Biggest speed difference is 3rd gear so I will prob take it for a spin in a few minutes after I flush the tranny fluid and refill, then see what I can come up with.

Thanks Flip. I will check in a few where I am at doing 62.

 

only reason I know what 62 is, is because i'm in khm. 100khm = 62mph lol

 

Well it looks like I have a 98+ ITR transmission. I hit 81 right as I was red lining 3rd.