Boost + hard launch + RXT Twin disk = problem

[rainmaker]

I'm getting pretty consistent 1.5x 60' with my M/T DRs (PP 19's) which I'm happy about. The problem I'm having is when launching hard and shifting around 7,600 - 7,800 RPMs, I'm having an intermittent problem where I hit the clutch, bang the next gear, and the tach just swings to redline. Its not like the clutch is slipping, more like the car is in neutral. It seems to happen primarily on the 2-3 shift. The clutch is not sticking to the floor, but I suppose its possible the pedal is not returning all the way back and I'm not noticing it. On the last occurrence, it happened on the 2-3 shift (engine quickly revs to redline), and then I banged the 3-4 shift and the engine quickly rev'd to redline again. I shifted to neutral and aborted the run and just coasted until the turnoff. The clutch works fine after that and holds power. I have the McLeod RXT with the billet steel FW and JPC clutch line. Its like the clutch is sticking. I just removed the stock spring assist and I'm going to try hitting the track again tomorrow. Any ideas? The clutch feels and performs great but this is a deal killer.

Sponsored

 

[jrsimon27]

Maybe your are not letting go the gas pedal??

 

[rainmaker]

Maybe your are not letting go the gas pedal??

No, I'm not power shifting, just speed shifting (well, trying too).

 

[Sam@Coastal]

Same problem I've had with a few of the McLeod units. They are sticking at high RPM. I would contact McLeod and see what they are willing to do for you.

 

[phunk]

I think I had it happen last night. I got a bit of wheel spin through second gear, but not so much I had to let out, I slam it into 3rd gear, and the engine goes straight to redline as if I am melting the tires off, but the car stayed straight as an arrow. I might have to keep my GoPro filming the next few times I drive because if I had been watching the speedo I would know for certain if it was clutch or tire spin.

 

[z06psi]

Sub'd on this one.

 

[Guard5.0]

Interested. Haven't noticed this yet on mine.

 

[smokinzx14r]

Had the same Problem with my Exedy clutch and fly wheel ... I also had the braided steel clutch line and the MGW shifter .. I did everything possible not to have this problem but still had the problem ... I now own a 2015 GT with a Automatic trans ..

 

[rainmaker]

Same problem I've had with a few of the McLeod units. They are sticking at high RPM. I would contact McLeod and see what they are willing to do for you.

Thanks Sam. I reviewed my previous logs and I can clearly see the RPMs jump and my MPH doesn't increase at all. I hit the track again today after removing the assist spring and the clutch didn't stick but I was shifting between 7,000 - 7,200. I wasn't able to make a clean pass shifting at higher RPMs because the track was slick, just the lower rpm pass below. I'll call McLeod and also see if I can do some more testing to determine if its completely random, occurs above a certain RPM, or if removing the assist spring helped eliminate the issue. BTW - do you know if anyone is making a plug & play 2-step for the 15-16 cars yet?

 

[rainmaker]

Had the same Problem with my Exedy clutch and fly wheel ... I also had the braided steel clutch line and the MGW shifter .. I did everything possible not to have this problem but still had the problem ... I now own a 2015 GT with a Automatic trans ..

The clutch feels great and the trans shifts like butter so I hope I can figure it out. If not, then I think I'll eventually just find someone who is making a kit to put a TH400 in the car.

 

[phunk]

BTW - do you know if anyone is making a plug & play 2-step for the 15-16 cars yet?

Let me know if you find a good 2-step solution. Although I wonder if that might trigger a misfire DTC. I cant stand the stock LC.

 

[sonic]

N2MB makes the 2 step and has the no lift feature. I have it and works great. if needed I have the wire pins and locations for installing on the 15. The owner has not updated the site for the 15 yet.

 

[sonic]

http://www.npcompleteperformance.com/wotbox

 

[Reds197]

I have the same clutch with a TVS. I have ran 1.52 sixty foots with zero issues. I launch around 5k with slicks and shift at 7700 RPM . I would contact McCleod and see what they say. This is the best clutch I have ever had.

 

[rainmaker]

I have the same clutch with a TVS. I have ran 1.52 sixty foots with zero issues. I launch around 5k with slicks and shift at 7700 RPM . I would contact McCleod and see what they say. This is the best clutch I have ever had.

UPDATE - I spoke with McLeod today and they seemed a little surprised about shifting in the 6,600 - 6,800 RPM range. Anyway, they did not use that as any type of excuse and after listening to me fully describe the problem they stated that it sounds like some type of hydraulic issue, not a problem with their clutch. They recommended using their p/n 14-301 hydraulic TOB and also switching to Wilwood EXP 600 High Temp Dot 4 brake fluid. I'm going to try switching to the EXP 600 and see if that helps. If not, I'll pull the clutch and inspect it and take pics, and I might try switching to their TOB.

Sponsored