clutch slipping at Drag Strip, dec 2015 query? new clutch time! OS Giken!!!

[2mad]

Very nice for a temperamental slippy clutch *12.85 at 107mph, 0-60ft 1.87secs* hope you sort it Jim

[jimGTS]

im happy to roll on this clutch until it gives me any grief on the road.

i pulled half a dozen 1.8-1.9x 60ft times and power seemed to hold fine up the whole strip aside from 1 "slippy" run (and that run i still beat a R33 GTR, ha). clearly must of just been the way i was slipping it to give me issues.

[Kongaroo]

Great times Jim - well done

What method did you use for the launch to get those 60ft times?

[jimGTS]

Hi dude, cheers

5-6k dumps pretty much. Not side stepping, just enough I was happy with.
You can just about make out the Rev counter in a couple of these runs.

https://www.youtube.com/watch?v=N8fjmKmFfJA

[QUOC2008]

Or best just get a carbonetic clutch you won't have any problems with that clutch slipping or any issues at all apart from it being a noise y clutch.

[Al-sw20]

Why do you waste time using the handbrake? Your launches are good otherwise. Looks like there was plenty of grip that day.

[jimGTS]

I only use the handbrake to keep the car still.
I have had occasions there where I've rolled back slightly. The track is very slightly up hill I believe.
I just feel more comfortable knowing I'm not going to trip any of the staging lights before I'm ready to go.
Im confused why you think it wastes time? These runs ignore reaction times.

It was a very warm day, 25+c, i assume this helped?
double edged sword i guess. warm day good for tyres, but not great for intake temps.

i think theres another tenth or 2 to be gained, maybe, but im pretty happy really.

[Al-sw20]

To me it just seems like another step that you could make a mistake with, costing you a clean run. Fair call though if your car does roll back for whatever reason, the staging area must still have a slight gradient down to the water trap.

I'd much rather have a hot day with great traction, than a cold slippery track. A cold day might give you a couple more mph at best. Every 0.1 you can pull off the 60ft will give you 0.2 at the end of the track.

My best ever on my first '91 turbo was 12.7 @ 109mph, my last '90 turbo was 12.8 @ 110mph. I had a stock clutch on the last car so had to baby it off the line. Try and get some more mph out of your car, you could be running 12.4 if you can get some more mph out of it.

[jimGTS]

So does this count as a 12.8 then no one ever seems to go to 2 decimals, ha.

But thanks.

I still have some room for more boost, I'm running between 1.1 to 1.2bar. I could possibly up this a little, add a little meth to my water injection tank. Keep det at bay.

Maybe a little burnout before hand.

Another 1.8 60ft, or less, and bit more boost, in theory I could maybe go a bit quicker.
My best run was with a 1.87 60ft, but best I had was a 1.80, that alone could net me a 10th or more before more boost.

All theory though

[Al-sw20]

Yep it's getting it all perfect in one run. With more boost and then torque off the line, you could possibly even dip into the 1.7s if you had enough grip.

That is how drag racing becomes addictive. It becomes more about challenging yourself to get the best out of your car.

[2mad]

So does this count as a 12.8 then no one ever seems to go to 2 decimals, ha.

But thanks.

I still have some room for more boost, I'm running between 1.1 to 1.2bar. I could possibly up this a little, add a little meth to my water injection tank. Keep det at bay.

Maybe a little burnout before hand.

Another 1.8 60ft, or less, and bit more boost, in theory I could maybe go a bit quicker.
My best run was with a 1.87 60ft, but best I had was a 1.80, that alone could net me a 10th or more before more boost.

All theory though

Meth meth meth Jim ... you wont regret it

[strawman]

i had this issue recently and i finished up changing the clutch for a new genuine toyota and a fidanza flywheel (assuming it was worn on 80000 miles)
Turned out that the clutch i took off was in ok condition.
The reason for it was the clutch fork ball joint was bone dry and full of road grime so it wasnt moving about and clearing properly.

Greased all that and its now alot easier on the foot too! as well as the annoying clutch creak has gone.

just a thought.........

[2mad]

Thats a very good thought .. if engagement and disengagement is compromised that could cause a problem .

[jimGTS]

A new pb to add but not a huge change.
Some methanol and an extra 0.05-0.1bar
(So 1.25bar peak)


12.82 at 109mph


I couldn't get off the line like last time, the above was with a 1.99 60ft time.
Had I repeated the launches from a month back I'm sure I would be in the 12.6-12.7 range now.

This again was on a hot 25c+ day.

No clutch slip issues at all.

[2mad]

Every tenth helps shame your launches weren't the same as last time.. love meth 50/50 wouldnt run a car in anger with out it

Hope you smash it next time Jim

[Al-sw20]

I managed 110.8mph on the stock gen2 fuel system. I did have 110 RON gas keeping things together though with the ct20b pushing 1.35 bar

[2mad]

slip/biting point = same thing, when pulling off the line is all i meant.

how else can you pull away, the clutch has to engage to get you moving.

On the sprints and hill climbs we just rev the engine and drop the clutch, no slipping at all then control the wheel spin with the throttle

Hard launch .. i think this is the best way too


Why ? clutches are expensive and a pain to swop out

[jimGTS]

https://www.youtube.com/watch?v=81UkaxR7WJg

[2mad]

12.82 @ 109mph vid was a hard launch .. very nice

[mr2toby]

Great times Jim. It's very addictive! What camera and mount are using to capture the racing?