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We have been working hard during these few months to test different methods of tuning software, different methods of turbo upgrades, etc for the R35 GTR. The Greddy turbo kit was first installed on our GTR few months ago and have reached torque numbers of over 738. Our customer Hing's GTR was also making over 750 in torque with the very same kit. Both vehicles were tuned with the Haltech unit. From what we've encountered was this mysterious "NO SHIFT" issue from 3rd to 4th gear. We've been working with Haltech to resolve this issue on a daily basis. We feel the TCM is definitely the reason behind this shifting issue once you reach high torque numbers.

SP Engineering GREDDY TT RACE MAP (HALTECH)


Hing's GREDDY TT RACE MAP (HALTECH)


We have recently introduced our Stage 1 SPE750 package and Wayne's R35 was next in line. Haltech was also used which produced torque numbers of 782 and encountered this "NO SHIFT" issue as well. Keep in mind the more power and torque we've made on race map this occurs on every setup we've tried. Running the power levels on pump gas levels did not have any issues at all.

Wayne's SPE750 Stage 1 RACE MAP (HALTECH)


Recently we've completed testing the COBB software on Waynes GTR. We wanted find a solution to this NO SHIFT issue in order to acheive reliable and powerful packages for the community and to factor anything out at this point. 91 pump gas was first in line and achieved power gains of 680 awhp and 676 Torque. 109 race fuel was next in line and achieved power gains of 720 awhp and 709 torque. From what we've learned, this "NO SHIFT" issue will ALSO occur using the COBB AP once you've reach high torque numbers shifting between 2nd and 3rd gear.

Wayne's SPE750 Stage 1 91 Octane VS 109 Octane (COBB MAP)


This definitely proves the TCM is the reason behind the problems we've faced. I am also aware COBB is working on a TCM program which we are definitely counting on. Haltech is also working hard to find a solution as well. We have definitely acheived the limits of the TCM before any additional power can even be made and hope there will be a solution shortly in order for us to break the 1000 awhp mark.

- Eugene @ SP Engineering

 

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Discussion Starter · #3 ·
wow thats lots of power, what about the tranny?
Too much power for the TCM. Regardless if you rebuild your transmission, reinforce it. You will not be able to shift at this point until the TCM is cracked 100%.

-Eugene @ SP Engineering
 

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what clutchs are in these transmissions? if they are stock have you thought of upgrading or do you think its not needed? TCM is getting some headway but alot of testing has to be done and alot has to be figured out, but looks like everyones working on it.
 

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Discussion Starter · #6 ·
what clutchs are in these transmissions? if they are stock have you thought of upgrading or do you think its not needed? TCM is getting some headway but alot of testing has to be done and alot has to be figured out, but looks like everyones working on it.
We definitely have plans on upgrading the transmission, however we have not seen any reason yet until these problems are solved. Clutch does not slip at all on our GTR's. The transmission will not shift to any high TORQUE numbers over 700 right at redline as you are about to engage into the next gear. If clutch slippage was the issue, the Haltech would of seen it.
 

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Can these not be tuned to produce high hp numbers, but low torque
numbers? Like Switzer? This is how they tune their kit so that
people can leave the tranny alone and not have shift issues as well.
Just wondering because I'm an not 100% sure of I know
if I am right or wrong.
 

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Discussion Starter · #8 ·
Can these not be tuned to produce high hp numbers, but low torque
numbers? Like Switzer? This is how they tune their kit so that
people can leave the tranny alone and not have shift issues as well.
Just wondering because I'm an not 100% sure of I know
if I am right or wrong.
Yes you can easily detune a vehicle. Lower the boost and keep it on pump gas only. 91 oct map has no issues which we offer with our stage 1 kits. As we all would love to run higher boost, more power, we will have to wait for the guru's to complete the TCM program.
 

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Yes you can easily detune a vehicle. Lower the boost and keep it on pump gas only. 91 oct map has no issues which we offer with our stage 1 kits. As we all would love to run higher boost, more power, we will have to wait for the guru's to complete the TCM program.
Im very impressed with your modified turbos!! they make very very good numbers! actually the best to date


When the tranny gets cracked , all hell will break loose!

so a recap of what is going on here.. AMS, Boost logic, SPE , Jotech, ALL these 1000whp projects Including Chucks car.. are pretty much useless UNTIL the tranny is cracked... intresting..

so all the peeps involved with these big HP projects have to stay on the sidelines...I guess we wont see a 9 sec GTR untill we get this solved!
 

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so a recap of what is going on here.. AMS, Boost logic, SPE , Jotech, ALL these 1000whp projects Including Chucks car.. are pretty much useless UNTIL the tranny is cracked... intresting..

so all the peeps involved with these big HP projects have to stay on the sidelines
I was thinking the same
 

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SPE has been working hard day and night to figure out this no shift issue while most of the people on this forum just gets 'over hyped' by all these 1000awhp builds. It's so funny how most tuners that has not reached the stage that SPE has achieved thinking they can get away with 1000awhp without any issues.

It has been proven FOR MONTHS that there is an issue with the TCM not being able to shift at high torque capacity GTR's. SPE bolt on turbos definitely has made its way to be the be the BEST bolt on sports turbo upgrade for ANY R35 GTRS that's able to SUSTAIN 1.8 bar of boost efficiently on 91 octane pump gas. I dare to challenge ANY R35 GT570 kit on the freeway run, I don't care who tune who's car and who run 10 sec times, I am up for a challenge on a highway run to prove the SPE turbos are the best TO DATE.

Btw, Eugene, please have Alex call me tomorrow, I think I have figure out what's happening with this no shift situation, because on my drive home tonight I made new revealation on the freeway. I am 70% sure now why we have no shift issue. I will be contact Nathan @ Haltech to reveal my findings.
 

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Can these not be tuned to produce high hp numbers, but low torque
numbers? Like Switzer? This is how they tune their kit so that
people can leave the tranny alone and not have shift issues as well.
Just wondering because I'm an not 100% sure of I know
if I am right or wrong.
high hp with low torque = slow times. This is a band aid to the real solution. Our R35 is not a HONDA by any means.
 

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As greddy is being installed. I am keeping my boost at 1.2 to 1.3 max.

Until all clear of what can be done
yea i am at 17psi. I do get the occasional clutch slipping on my car, but we just data logged that and i should have that fixed shortly. seems my clutches slip more at partial throttle then full throttle.
 

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When the tranny gets cracked , all hell will break loose!

so a recap of what is going on here.. AMS, Boost logic, SPE , Jotech, ALL these 1000whp projects Including Chucks car.. are pretty much useless UNTIL the tranny is cracked... intresting..
so all the peeps involved with these big HP projects have to stay on the sidelines...I guess we wont see a 9 sec GTR untill we get this solved!
Yes. There have been other issues that have come up and been solved during the development phase of many of the products. Problems have come up been solved, and then a new issue arises. Most of the consumers will never hear this stuff.

I have said from the start that the engine is the easy end of this car, the transmission is the issue. However in the future, nearly every single car will have a dual clutch variant. Expect to see them nearly everywhere due to efficiency and emissions testing.
 
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