UK 2019 GT Manual - Dragstrip woes

[Braski]

If your on a stock tire just do a quick burn out to dust them off. Don't bother launching any higher then 1250 rpms unless your willing to smoke your clutch by riding it out. Also try shifting into 2nd sooner so your not blowing them off in 2nd which will result in wheel hop. Without riding the clutch you should still be able to get down to a 2.1 60' just basically launching on idle. I agree these s550 manual cars are tough to launch. Slicks will be your best friend at the track but if you want to kill the wheel hop on the street your going to have to start upgrading the IRS!

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[Braski]

OP what tire is on your car btw?

 

[cib24]

If your on a stock tire just do a quick burn out to dust them off. Don't bother launching any higher then 1250 rpms unless your willing to smoke your clutch by riding it out. Also try shifting into 2nd sooner so your not blowing them off in 2nd which will result in wheel hop. Without riding the clutch you should still be able to get down to a 2.1 60' just basically launching on idle. I agree these s550 manual cars are tough to launch. Slicks will be your best friend at the track but if you want to kill the wheel hop on the street your going to have to start upgrading the IRS!

Thanks. The car feels like it has no power below 3000 RPM in any case, so launching off idle is really slow. I've tried it 4 or 5 times and each time I get no wheel hop and it all feels good but then my 60 foot is 2.5. I will give it a go again next time to see if I have better success.

Maybe it's the revised MT82 ratios from 2018 onwards plus a 3.55 rear? The gearing in 1st and 2nd is just a little too long?

Shifting in 1st gear at 7200 RPM into 2nd drops the RPMS to 5400 and doing the same into 3rd gear drops the RPMs to about 5500 RPM.

The stock tyres are Michelin Pilot Sport 4S.

I also get no wheel hop in 2nd at all. A brief tyre chirp and that's it. Only bad hop in 1st.

Launching on the street is less important. We don't have many straight roads here so there is limited scope for traffic light drag racing as everything is a roundabout (traffic circle).

Revised gearing below:

 

[Burkey]

I can't figure it out. I had 11 runs today and only 3 were "ok" 2.3-2.4 60 foots. The other 8 runs had 2.5-2.7 60 foots mainly because I had issues launching or while in 1st gear. I basically run into 1 of 4 issues almost every time:

1. Very bad wheel hop
2. Car bogs down due to being too gentle off the line, and then mega wheel hop
3. Excessive tyre spin in 1st and 2nd gear
4. Shift into 2nd gear and the car falls flat on its face

Both weekends its been 45-50 F outside with a 20-25 mph headwind.

My default procedure is to put the car in drag mode, turn off launch control, hold the traction conrol button for 10 seconds to turn ESC off (Advancetrac in the USA).

I run 22-23 PSI in the tyres as per recommended on via searching.

I have tried 5-6 second linelock burnouts prior to staging. I have tried 1-2 second burnouts. I have tried zero burnouts.

I never dump the clutch, always slip it and ride it until about 4500 RPM in 1st.

I can't seem to leave the line with any real aggression because I usually get wheel hop, and if I don't get that with an agressive start (still a terrible 60 foot at 2.3 seconds) then the car kept falling flat in 2nd gear. The times it didn't fall flat I was 4 mph faster in the 1/8th and 5 mph faster in th 1/4.

I'm at a loss other than putting slicks on it. I think any wheel hop solutions will just put morestress on the half shafts and probably snap them if I try to leave hard.

I had a 2000 4.6L Mustang GT in High School when I grew up in the USA and I could consistently get 2.0-2.1 60 foots on bald Kumhos in that car. This car is a completely different animal and I'm really frustrated with it.

There’s no doubt that adding grip “should” add stress. The issue here is that the stress of wheelhop is far more significant than what the addition of grip will bring.
As a prime example, a friend of mine recently broke his 2000hp rated DSS halfshafts. He’s never launched the car on the strip and has only ever used a street type radial and it doesn’t even have half of the rated power of the axles.
The car was wheel hopping at the time the breakage occurred.

The other thing is that a bias ply acts as a cushion. You won’t be able to make it slip. It won’t generate hop. It will however allow the rim to wind-up a little inside the tyre, taking some of the brunt of the shifts.

I’d suggest that you’re highly likely to break an axle if you continue to create wheelhop on the strip.
The video below is a 5k clutch dump on MT ET streets. Stock clutch. 800hp shafts.
The car almost stalls off the line. Grip is INSANE.

 

[Braski]

Thanks. The car feels like it has no power below 3000 RPM in any case, so launching off idle is really slow. I've tried it 4 or 5 times and each time I get no wheel hop and it all feels good but then my 60 foot is 2.5. I will give it a go again next time to see if I have better success.

Maybe it's the revised MT82 ratios from 2018 onwards plus a 3.55 rear? The gearing in 1st and 2nd is just a little too long?

Shifting in 1st gear at 7200 RPM into 2nd drops the RPMS to 5400 and doing the same into 3rd gear drops the RPMs to about 5500 RPM.

The stock tyres are Michelin Pilot Sport 4S.

I also get no wheel hop in 2nd at all. A brief tyre chirp and that's it. Only bad hop in 1st.

Launching on the street is less important. We don't have many straight roads here so there is limited scope for traffic light drag racing as everything is a roundabout (traffic circle).

Revised gearing below:

Yup, trans and rear ratio are not making it any easier on you. Try a slick and let her rip!

 

[cib24]

There’s no doubt that adding grip “should” add stress. The issue here is that the stress of wheelhop is far more significant than what the addition of grip will bring.
As a prime example, a friend of mine recently broke his 2000hp rated DSS halfshafts. He’s never launched the car on the strip and has only ever used a street type radial and it doesn’t even have half of the rated power of the axles.
The car was wheel hopping at the time the breakage occurred.

The other thing is that a bias ply acts as a cushion. You won’t be able to make it slip. It won’t generate hop. It will however allow the rim to wind-up a little inside the tyre, taking some of the brunt of the shifts.

I’d suggest that you’re highly likely to break an axle if you continue to create wheelhop on the strip.
The video below is a 5k clutch dump on MT ET streets. Stock clutch. 800hp shafts.
The car almost stalls off the line. Grip is INSANE.

Thanks. This makes complete sense to me.

I'll be honest I've had about 3 runs where the wheel hop was really had up to 5000-6000 RPM, 1/4-1/2 throttle and letting out to save the car. I wouldn't be surprised either if I got under the rear of the car to see the diff had moved.

I have the BMR CB005 to install eventually with my 4.09 final drive. Given its a manual should I also be looking at lower control arm bearings and diff poly bushes?

I'm okay breaking a half shaft. The fucker has pissed me off enough and that way the girlfriend won't question why I need upgraded shafts

 

[cib24]

Yup, trans and rear ratio are not making it any easier on you. Try a slick and let her rip!

What is the recommended rear wheel size and rear tyre size for slicks? I don't think I can buy the slicks very easy here in the UK, but I assume it's either Hoosier or MT ET Street R-Bias tyres.

18x9?
18x9.5?
17x9?
17x9.5?

 

[Braski]

What is the recommended rear wheel size and rear tyre size for slicks? I don't think I can buy the slicks very easy here in the UK, but I assume it's either Hoosier or MT ET Street R-Bias tyres.

18x9?
18x9.5?
17x9?
17x9.5?

I've ran both and they both hooked awesome but the mt are more stable. I have 17x9.5 rears and 18x5 up front.

 

[cib24]

I've ran both and they both hooked awesome but the mt are more stable. I have 17x9.5 rears and 18x5 up front.

Thanks. So, a 17x9.5 wheel fits over the rear brakes on a GT PP1 spec car? Do you mind disclosing the offset of your wheels and any special studs or lug nuts required?

What size MT ET R-Bias tyre did you run?

 

[Braski]

Thanks. So, a 17x9.5 wheel fits over the rear brakes on a GT PP1 spec car? Do you mind disclosing the offset of your wheels and any special studs or lug nuts required?

What size MT ET R-Bias tyre did you run?

If you search my build thread "project midnight" all the info should be in there!

 

[Ghost50]

I found myself nodding in agreement and sharing your frustrations when reading this thread.

I was in the same boat as you. I’m a PP1 MT82 car except I’ve got the 373’s.

Prior to any mods I took it out to the local strip here and wanted to see what it could do. Each time I found myself driving home frustrated.

My best stock run was a 12.87 at, if I recall correctly, 116mph. The night I managed this it was really humid and the DA correction said I would’ve been at a 12.4. Who knows how accurate that is but at 86% humidity (I live in Houston) it isn’t the most ideal conditions to run lol

That night and the previous trip I made out there all were the same as you; wheel hop and spin. Which meant lousy 60’ times.

The wheel hop was violent. I tried launching from idle, launching at 3500 and slipping the clutch, launching at 4000 and dumping the clutch and every other combo possible and nothing mattered.

I never unplugged the nanny plug but did race in drag mode with advancetrac turned off.

Driving home that night I told myself I wouldn’t put it on the track again until I stiffened the suspension up. So I added everything in my signature.

Since the additions I have not made any runs yet but I plan to take it out next month. I want to take advantage of March and April here before it gets stupid hot and humid.

I can’t wait to see what it does. Later this year I’ll buy a drag pack with slicks and might put 4:09’s in it.

That launch that Burkey posted was awesome.

Good luck to you! Can’t wait to see what the cradle lock out and slicks do for you.

 

[cib24]

If you search my build thread "project midnight" all the info should be in there!

Thanks! I had a look through and roughly figured it out. I think your rear wheels have a ET43.5 offset but I wager I will be okay with ET38 which is a typical 17x9.5 offset for the Japanese car scene. Brands like Einkei or Rota copies are far easier to get over here than anything like Race Stars or Welds.

Last question to all - MT ET Street R Bias seem to have a slightly stiffer sidewall than Hoosiers, and therefore I shouldn't run into any scary handling issues by leaving the stock radial 275 width Michelin PS4S tyres on the front wheels?

I did a lot of reading and the guys that suggest against it are all running 130, 140, 150 mph in the 1/4 and also running 15" wheels in the rear with very large slicks. Since this won't be my situation I assume I should be okay just changing the rear wheels and tyres with bias ply slicks?

 

[cib24]

I found myself nodding in agreement and sharing your frustrations when reading this thread.

I was in the same boat as you. I’m a PP1 MT82 car except I’ve got the 373’s.

Prior to any mods I took it out to the local strip here and wanted to see what it could do. Each time I found myself driving home frustrated.

My best stock run was a 12.87 at, if I recall correctly, 116mph. The night I managed this it was really humid and the DA correction said I would’ve been at a 12.4. Who knows how accurate that is but at 86% humidity (I live in Houston) it isn’t the most ideal conditions to run lol

That night and the previous trip I made out there all were the same as you; wheel hop and spin. Which meant lousy 60’ times.

The wheel hop was violent. I tried launching from idle, launching at 3500 and slipping the clutch, launching at 4000 and dumping the clutch and every other combo possible and nothing mattered.

I never unplugged the nanny plug but did race in drag mode with advancetrac turned off.

Driving home that night I told myself I wouldn’t put it on the track again until I stiffened the suspension up. So I added everything in my signature.

Since the additions I have not made any runs yet but I plan to take it out next month. I want to take advantage of March and April here before it gets stupid hot and humid.

I can’t wait to see what it does. Later this year I’ll buy a drag pack with slicks and might put 4:09’s in it.

That launch that Burkey posted was awesome.

Good luck to you! Can’t wait to see what the cradle lock out and slicks do for you.

Thanks for the words of encouragement. I wasn't expecting miracles out of the box but have been really frustrated with how the car has been performing.

I suppose I can't discount the 45-50 F degree weather outside this time of year as that means everything is cold, so grip won't be the same when it's 80-90 degrees outside in the summer.

My wheel hop has been very violent too and I'm going to start with the CB005 and slicks, but I think I may need to consider poly diff bushing inserts and LCAs eventually. Hopefully never half shafts but I wouldn't be surprised.

I've also got a set of 4.09s and a Torsen diff to install but I'm going to hold off and stay on the 3.55s until I can consistently launch. I hope the slicks will allow a 1.7-2.0 60 foot in this colder weather and in summer possibly better....hopefully. Otherwise, I'm going to stop drag racing this car as it's too frustrating when. Every BMW, Audi, Merc, R35 and Tesla at the strip launches so much easier and better.

 

[Burkey]

Thanks! I had a look through and roughly figured it out. I think your rear wheels have a ET43.5 offset but I wager I will be okay with ET38 which is a typical 17x9.5 offset for the Japanese car scene. Brands like Einkei or Rota copies are far easier to get over here than anything like Race Stars or Welds.

Last question to all - MT ET Street R Bias seem to have a slightly stiffer sidewall than Hoosiers, and therefore I shouldn't run into any scary handling issues by leaving the stock radial 275 width Michelin PS4S tyres on the front wheels?

I did a lot of reading and the guys that suggest against it are all running 130, 140, 150 mph in the 1/4 and also running 15" wheels in the rear with very large slicks. Since this won't be my situation I assume I should be okay just changing the rear wheels and tyres with bias ply slicks?

My advice is to be VERY careful with your selection of wheel. I made the mistake of using something fairly cheap. From memory they’re 17x 9 with a +35 offset.
The offset isn’t ideal (+40 would fit more easily under the guard) but that wasn’t the problem.
I simply use my airbags to an advantage, pumping them up which gives a higher spring rate and takes some negative camber out of the static position. You won’t have that luxury.
The issue for me was the internal diameter of the rim barrel. Clearance was “only just” (I’m talking literally cigarette paper clearance). To cure this, I took a flap disc to the most outer portions of the brake caliper, removing maybe 0.5mm of material. No rub on the rim barrel so far.
Call it a cautionary tale.
Best of luck with it!

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