[2023_ZL1-AUTO]

So, it seems I have no luck with my drag pack setup(s). My new Vitesse's, I had the wheels checked with no tires check for balances and they are good! But, when the tires are mounted and they Road Forced balance them. They have to rotate the tires on the wheel 5, 6, even 7 times, just to get to a crappy road force # of 36+ to 47+.

My car has a bad vibration, at slow speed it's not so noticeable, but the faster I go the worse it gets. I've had the rear-end and front-end alignment done after replacing the factory suspension with BMR parts and doing the 15" conversion. So that's not the issue. I've confirmed yet again, it's not the car itself by putting my factory wheels and tires back on and driving the car. It drivers darn near perfect with no noticeable vibration.

So my questions is: Those that run a drag pack/drag radials: Do you have vibration too, and do you just put up with it?

Maybe I need to ditch these MT ET Street R's and go with Hoosier D2's?. But, on the 17" wheel, the size options are limited. I'm not quite ready to go with 15's yet since I will need to buy, yet again more wheels to do so.

This wheel journey I've been on... I should have immediately did the 15" conversion back a year ago, and I'd not be sitting on 3 complete set of wheels. UGH !

Thanks in advance for any info!

[KingLT1]

Been there done that. Hence why I ride on 20" wheels with a 555r2. Drag packs simply sacrifice too much quality and comfort on the street. Maybe of I was in my 20's still. Best bet is to put a harder tire back on it and go with some sort of traction management setup ... smooth boost boost by gear or motec.

[Dynamical]

Yeah it’s definitely a trade off IMO. I just went from the stock run flats to Nitto R2 and Nitto fronts. Stock tires were a better ride. I have run MT ET ST R 305/45/17 to and from the track almost 300 mile round trip. That’s definitely a compromise for the street lol. I ran the MT SS on my F bodies years ago 24/7. It wasnt too bad. I appreciated the performance more than anything.

[swisstyphoon]

I’m honestly starting to think MT ET Street R consistency is a bit hit or miss lately.

I ran into very similar issues on my setup. One of my ET Street R’s needed a huge amount of weight on one side and had visible wobble/runout even after multiple re-mount and rotation attempts. The wheel itself checked out true on the balancer.

You could even visibly see the tire moving side to side while spinning on the balancing machine.

At higher speeds the whole car would shake badly — over ~120 mph it honestly didn’t feel safe anymore.

What’s interesting is that the second tire was noticeably better, which makes me think it’s not just “normal drag pack vibration” but more tire-to-tire inconsistency.

I recently switched to ET Street S/S for class rules and even there I’m seeing one tire behave much better than the other.

So no, I don’t think you’re crazy or alone with this issue.

[KingLT1]

Originally Posted by Dynamical

Yeah it’s definitely a trade off IMO. I just went from the stock run flats to Nitto R2 and Nitto fronts. Stock tires were a better ride. I have run MT ET ST R 305/45/17 to and from the track almost 300 mile round trip. That’s definitely a compromise for the street lol. I ran the MT SS on my F bodies years ago 24/7. It wasnt too bad. I appreciated the performance more than anything.

What tires came on yours stock? Imo the Nittos are a much better ride than the stock good year run flats that came standard on my SS.

Originally Posted by swisstyphoon

I’m honestly starting to think MT ET Street R consistency is a bit hit or miss lately.

I ran into very similar issues on my setup. One of my ET Street R’s needed a huge amount of weight on one side and had visible wobble/runout even after multiple re-mount and rotation attempts. The wheel itself checked out true on the balancer.

You could even visibly see the tire moving side to side while spinning on the balancing machine.

At higher speeds the whole car would shake badly — over ~120 mph it honestly didn’t feel safe anymore.

What’s interesting is that the second tire was noticeably better, which makes me think it’s not just “normal drag pack vibration” but more tire-to-tire inconsistency.

I recently switched to ET Street S/S for class rules and even there I’m seeing one tire behave much better than the other.

So no, I don’t think you’re crazy or alone with this issue.

MT has been inconsistent for years...I know some don't even attempt to balance them.

[Joshinator99]

When I was on 17” ET Street R, I was able to have them road force balanced and they were smooth as silk. But after going to the 15” conversion, you can’t really balance them since weights in the barrel would hit the rear calipers… so it definitely shakes at the top end of the track… wish I could go back to 17’s honestly.

On the street I run 20” 315/30/20 R888R on OEM 1LE wheels. No problems at all…aside from potholes lol

[Dynamical]

Originally Posted by KingLT1

What tires came on yours stock? Imo the Nittos are a much better ride than the stock good year run flats that came standard on my SS.



MT has been inconsistent for years...I know some don't even attempt to balance them.

My LT1 came with square setup 245/40/20 Goodyear eagle f1 asymmetric 2 rof.
Yeah, that's what I thought too. I was surprised the ride doesn't feel as smooth as stock setup. Maybe I need to have them rebalanced by a better shop. They hook better for sure though.
The only other thing I can think of is the stock sidewall is a little taller. 27.7 vs 27.2. Overall it's not bad.
Originally I wanted the MT S/S like I used to run years ago but I saw the negative comments so ended up with Nitto r2. I used to run the S/S 15 years ago lol. No issues back then that I can remember

[2023_ZL1-AUTO]

On my factory wheels I have Nitto R555R's front and back.