[Tom C]

A GT-R with AAM resonated mid-pipe, generic 93 octane Cobb tune and HKS drop-in filters ran at the track rental last Friday at MIR. The first run was done (accidentally) without being in any R modes. The car ran 12.2X @ 116.1 mph. The car was cooled down for about 40 minutes and ran again with R R R (no launch control). It ran 11.64 @ 121.99 mph. On the next run (40 minutes later) the car ran 11.55 @ 122.17mph (no launch control). I wouldn't have thought that R configuration made that much of a difference on the traps. Any ideas why?

Tom

 

[Neil Switzer]

The transmission in R mode is much more efficient, but without the full timeslips it is difficult to establish where exactly you made up your time.

By the way, we can tune your car remotely and you should pick up at least 5mph.

 

[Dano]

Two main reasons for this is quicker shifts and more freedom before traction control quicks in in "R" mode.

 

[Goonthree]

It shouldn't make that much difference and basically impossible. The R mode is not going to be equivalent of 60 Hp over 11 seconds. Many have run a little slower. Let the car cool 40 minute and run without R mode, it will not be 6 mph slower.

 

[GTB/ZR-1]

Probably cool down, cooler temps & RRR mode combination.

 

[Church]

My car is no faster in R mode than it is in auto non R or Manual non R. It's all the same in my car.

 

[jamie]

It shouldn't make that much difference and basically impossible. The R mode is not going to be equivalent of 60 Hp over 11 seconds. Many have run a little slower. Let the car cool 40 minute and run without R mode, it will not be 6 mph slower.

I was also at MIR at that rental last Friday with my Cecil tuned GTR with HKS resonated midpipe and ran a best of 10.7 at 129 as the temps were too hot for any really great runs. I rarely shift my car and leave it in auto and RRR and it seems to always run the best numbers in that setup. On that day I thought I would give manual auto mode a try, leaving it in manual and RRR off and it ran almost identical times as Auto and RRR. I also decided to try the canned Cobb 93 stage 2 and I also ran that in the same 2 modes as well and ran a worst of 11.31 at 122+mph and a best of 11.22 at almost 123mph so I would have to think the discrepency in times and mph had more to do with driving and the way the car was leaving and maybe some temperatures that caused the differences, not the RRR mode.

 

[Dano]

I think every car is going to be a little different. If I didn't have it in R mode in my 09 the traction control would intervene too early and kill any sort of run. Sometimes it would even kick in without any lights flashing on the dash. R mode was more lenient. Never tried it with VDC off and I still haven't tried it with my 2012.

 

[Tom C]

I was also at MIR at that rental last Friday with my Cecil tuned GTR with HKS resonated midpipe and ran a best of 10.7 at 129 as the temps were too hot for any really great runs. I rarely shift my car and leave it in auto and RRR and it seems to always run the best numbers in that setup. On that day I thought I would give manual auto mode a try, leaving it in manual and RRR off and it ran almost identical times as Auto and RRR. I also decided to try the canned Cobb 93 stage 2 and I also ran that in the same 2 modes as well and ran a worst of 11.31 at 122+mph and a best of 11.22 at almost 123mph so I would have to think the discrepency in times and mph had more to do with driving and the way the car was leaving and maybe some temperatures that caused the differences, not the RRR mode.

Here is the thing... the non-R mode run was in the late morning...before the temps started creeping up into the 70s. The R mode runs were in the early afternoon. So I would have thought that that morning run would have trapped higher (all things being equal) with the better air. Is there an adaptive software with the GT-R's transmission (like on some of theother cars I have owned)? Maybe the car was being babied too much lately and after the first run the transmission software adapted. Would that make sense?

For those that were asking about the slips.. I believe the 60' times were 2.05s on the non-R mode run... and 1.99 and 1.96 on the R mode (non-LC) runs. The 1/8 mile traps were 91.8mph (non-R mode) and 97.1mph and 97.8mph on the R mode runs.

Tom