[Speedy1975]

Originally Posted by 17CamaroZL1

Once I feel like I've ran as fast as possible on the factory rubber, I'll probably never run them again, unless I run a street tire event.

My slicks are just about shot after 200ish passes and I'm shopping the Mickey Thompson ET Street R tire as the replacement. Those are a very sticky drag radial that is street legal, so will work for street tire events

So I see a 10.94 in your sig (good video too), was that stock? So you did it?

[Fraxum]

Originally Posted by 17CamaroZL1

Fraxum, that sounds almost totally backward. A cool engine should pull less timing than a hot one. Sure. You need the oil and trans temps to be warm, but you shouldn't have to make sure they're at 200. The only issue I've ran into with temps being too low was when the trans was below 150 and it was slow to shift into 4th and caused the car to hit the rev limiter. If you're not cooling that supercharger down, you're going to be giving up some mph. I keep my hood up as much as possible between runs and while sitting in the staging lanes. Don't idle the car while sitting in the staging lanes either, because that will heat you up in a hurry. If you can't pull right up to the lane to make a pass, shut it off and pop the hood. Try to keep the sun off of the supercharger too. If you have good cool air, say 50 or less, and can lap right back around and run again, the car will stay good and cool and mph good for 5 or 6 back to back passes or more. When it's hot out, you'll see a mph drop on your 3rd pass. The supercharger should feel cool to slightly warm to the touch. If it feels hot when you touch it, you're leaving a good 2 to 3 mph on the table.

I know that sounds backward. But at the track:

#1 Off the street 6 PM 122 mph - DA 400 (6 PM)
#2 10 min later 121.5 mph - DA 400 (I spun on this run)
#3 45 min later 120.0 - DA 295
#4 2 hr 45 min later 120.5 - DA 121

Other than the Rotofab all stock. These MPHs are about the same before and after the RF. Some of my runs are in the high teens. Normally I leave the hood open, but my runs look about like this. That night I decided to leave it closed.

Track mode all nannies off.

I guess I just have a slow ZL1.

[17CamaroZL1]

Originally Posted by Speedy1975

My slicks are just about shot after 200ish passes and I'm shopping the Mickey Thompson ET Street R tire as the replacement. Those are a very sticky drag radial that is street legal, so will work for street tire events

So I see a 10.94 in your sig (good video too), was that stock? So you did it?

That's exactly the tire I was looking at once I find a wheel.

Thanks! That is bone stock down to the tire and I ran that last December. Felt like I may have left a little on the table. I had ran 129.5 mph earlier that night, but the track wasn't there yet. Then when I ran the 10, I knew it could be launched harder if the track was a little better. Even though a 1.71 60' is good, I very well could've been out past the 60 mark before I was wide open, where on a good sticky track, I can get it to the floor pretty fast. On top of that, the car feels like and shows evidence that it is getting faster as it racks up usage.

[17CamaroZL1]

Originally Posted by Fraxum

I know that sounds backward. But at the track:

#1 Off the street 6 PM 122 mph - DA 400 (6 PM)
#2 10 min later 121.5 mph - DA 400 (I spun on this run)
#3 45 min later 120.0 - DA 295
#4 2 hr 45 min later 120.5 - DA 121

Other than the Rotofab all stock. These MPHs are about the same before and after the RF. Some of my runs are in the high teens. Normally I leave the hood open, but my runs look about like this. That night I decided to leave it closed.

Track mode all nannies off.

I guess I just have a slow ZL1.

No such thing. Lol! Some might be faster than others, but there's no slow ones.

One of our fellow ZL1 owners has shown a .1 and 3 mph gain by removing his Rotofab. I'm sure there's a gain to be had with the right tune with it, but on the stock tune, it seems the Rotofab hurts the performance. Something to try on top of keeping the supercharger cool.

[Fraxum]

Originally Posted by 17CamaroZL1

No such thing. Lol! Some might be faster than others, but there's no slow ones.

One of our fellow ZL1 owners has shown a .1 and 3 mph gain by removing his Rotofab. I'm sure there's a gain to be had with the right tune with it, but on the stock tune, it seems the Rotofab hurts the performance. Something to try on top of keeping the supercharger cool.

Hmm, after installing the RF I did see an ET improvement of about 1/10th given the DA/60'. Maybe once the car adjusts to the RF maybe then there is a hit.

But this low mph thing has been going on for a while before the RF. I suppose I should start logging my runs. Do you know if the PDR with the Cosworth or PI Toolbox would be helpful?

Otherwise I guess I will buy another HP Tuners.....

[17CamaroZL1]

There's really not a lot of helpful info for drag racing in Cosworth. It does show minimum and maximum: tire temps and pressures, coolant temps, oil temps, trans temps, etc. I wouldn't say it's useless, but you'd be better off with hptuner or something for logging. That way you can see info that makes a bigger difference in performance like IATs, boost levels, ignition timing, spark retard, fuel, etc. That way you have a better picture of what's going on in different conditions and circumstances. I think it would be even more handy once you start swapping out parts. I've thought about buying hptuner just for logging purposes, and then when I'm ready to give up my warranty and start modding, I could see exactly how the car reacts to changes and I could try some simple tuning stuff on my own. I'd like to be able to dial back or even remove the torque management to see how much of a difference that would make at the strip.

One drag related thing that is kind of neat in Cosworth, is one page shows an aerial view of the track/strip that plots a line as you make the pass, and off to the side is a graph that shows your throttle input at any given time in the run. You can see pretty quick what a difference in grip does to how you operate the throttle. Just thinking about this makes me want to load up my PDR footage from last week and see how crazy my throttle graph looks from all the spinning and peddling I was doing.

[Fraxum]

Originally Posted by 17CamaroZL1

That's exactly the tire I was looking at once I find a wheel.

I went with MTT-3472 ET Street S/S, P305/45-17 as these have a sticky compound but have at least a little water run off if you get stuck in the rain. But at low pressure @100+ they will wander around a bit. Spooky when you are used to the on rails ZL1 feeling.

and Race Star 17x10.5 5x120 32 Offset 92 Drag Star Bracket Racer Metallic Gray Wheel
RAS-92-705253G

A pair $468.58 shipped.

I was going to go with black, but the grey was cheaper and sort of match the stockers. Later I want to go with black MRR ZR1 19" wheels and Toyos R888Rs in the back. Once you start modding these cars you need more grip than the stockers. One guy I met at Atco with a new ZL1 already totaled his ZL1 on the street after getting loose and meeting a guardrail. He was fine thankfully. With 800 miles on the clock his ZL1 was running faster at atco than my ZL1 with 6K miles. And I shared my launching techniques with him. Funny. He should tell me what he was doing.

Then you need this package
+ https://www.summitracing.com/parts/RCE-601-1428-10

Hint: When installing the RaceStar lugs lightly oil the outside of the lug barrels. 140 torque.

No worries about moving the drivers side rear wheelwell connector. I think Chevy moved it for us.

I like to keep the air pressure monitor with DRs:

https://www.gmpartsdirect.com/oem-pa...r-nut-13581557

https://www.gmpartsdirect.com/oem-pa...ensor-13598787

[big dave]

David has run 10s stock. I'm surprised others haven't done it also. When you consider that the Z06s have run 10.4s stock, the ZL1 shouldn't be far behind. Sure, there's a weight disadvantage, but I"m sure the 10 speed makes up some of that difference.

I've run 10.99 also at full weight.

[BMWM.D.]

Originally Posted by Fraxum

I went with MTT-3472 ET Street S/S, P305/45-17 as these have a sticky compound but have at least a little water run off if you get stuck in the rain. But at low pressure @100+ they will wander around a bit. Spooky when you are used to the on rails ZL1 feeling.

and Race Star 17x10.5 5x120 32 Offset 92 Drag Star Bracket Racer Metallic Gray Wheel
RAS-92-705253G

A pair $468.58 shipped.

I was going to go with black, but the grey was cheaper and sort of match the stockers. Later I want to go with black MRR ZR1 19" wheels and Toyos R888Rs in the back. Once you start modding these cars you need more grip than the stockers. One guy I met at Atco with a new ZL1 already totaled his ZL1 on the street after getting loose and meeting a guardrail. He was fine thankfully. With 800 miles on the clock his ZL1 was running faster at atco than my ZL1 with 6K miles. And I shared my launching techniques with him. Funny. He should tell me what he was doing.

Then you need this package
+ https://www.summitracing.com/parts/RCE-601-1428-10

Hint: When installing the RaceStar lugs lightly oil the outside of the lug barrels. 140 torque.

No worries about moving the drivers side rear wheelwell connector. I think Chevy moved it for us.

I like to keep the air pressure monitor with DRs:

https://www.gmpartsdirect.com/oem-pa...r-nut-13581557

https://www.gmpartsdirect.com/oem-pa...ensor-13598787

I did the ET Street R in the same size on those 10.5” Race Stars. The car was rock solid at over 130 mph. That was really my biggest fear, and I was surprised at how good it felt.

[Fraxum]

Originally Posted by BMWM.D.

I did the ET Street R in the same size on those 10.5” Race Stars. The car was rock solid at over 130 mph. That was really my biggest fear, and I was surprised at how good it felt.

Hmm maybe the Rs are better. And I was only at about 26 pounds.

[Fraxum]

Originally Posted by big dave

David has run 10s stock. I'm surprised others haven't done it also. When you consider that the Z06s have run 10.4s stock, the ZL1 shouldn't be far behind. Sure, there's a weight disadvantage, but I"m sure the 10 speed makes up some of that difference.

I've run 10.99 also at full weight.

I tried. I am no lightweight @ 225 pounds. I have run the ZL1 at least 100 times stock. I could do no better than a 1.74 60', mid 11.4s, and barely touched 126 mph once. And in air as good as -1,500 DA.

So either I suck at this, or my ZL1 is a slow one, or a little of both.

[BMWM.D.]

Originally Posted by Fraxum

Hmm maybe the Rs are better. And I was only at about 26 pounds.

I’m not sure. My friend runs the ET Street SS as his regular street tires on his ~580 whp Chevelle, and said they don’t hook all that well. And since I swap my tires at the track, I figured the R would be a better choice. It only felt a little floaty on one pass where I aired them down a few pounds. I kept them at 24 psi the rest of the time, and they were great.

Originally Posted by Fraxum

I tried. I am no lightweight @ 225 pounds. I have run the ZL1 at least 100 times stock. I could do no better than a 1.74 60', mid 11.4s, and barely touched 126 mph once. And in air as good as -1,500 DA.

So either I suck at this, or my ZL1 is a slow one, or a little of both.

I had super low expectations before I took my car out for the first time earlier this month. I’d seen a bunch of guys trapping low 120’s, and figured I’d be happy to match GM’s official time of 11.4 @ 126. Being that it was 100 degrees at the track the day before, and it’s at ~800 ft of elevation to begin with, I wasn’t expecting much.

Thankfully, the track prep was good and it cooled off late in the night. DA never got below about 1300 though. Still, somehow my first pass in the car was an 11.1 @ 129.x. That was after a bunch of idling in line to get in and get through tech. As the night cooled and I got a little more experience launching the car, I shaved that down to a 10.79 @132.7.

Now, my car isn’t stock. But what I’d done at the time isn’t known to make much power on the dyno. Headers are good for 15 whp or so from what I’ve seen. The Roto-Fab, who knows. I didn’t think the Mamo ported TB would do much either. Maybe the secret is in my amateur tuning, lol. I didn’t do much other than correct the MAF curve and get WOT fueling where I wanted it.

Maybe your car is down on power? I doubt it’s your driving, as I’m far from an experienced drag racer. I’ve been going to Famoso every now and then since my senior year of high school in 2000, but this was my first outing in 8 years. Anyway, best of luck on getting it figured out.

[Speedy1975]

If you really wanna get serious, a lot of it is car setup. By this I mean:

The right fuel
The right amount of fuel in the tank
The right tire/wheel setup
The right tire pressure (not too low and not too high)
Junk weight removed from the car (I've seen people go down the track with a cooler in the trunk!)
Warm fluids and a cool supercharger

I've seen as much as a 3-4 tenths gain with nothing more than the right setup.

I've got a couple more things to test on the Hellcat just to see what it'll do with tires/wheels/driveshaft (hoping for a 10.4x), then it's time to bump the power and shoot for 10.0.

[big dave]

Originally Posted by Fraxum

I tried. I am no lightweight @ 225 pounds. I have run the ZL1 at least 100 times stock. I could do no better than a 1.74 60', mid 11.4s, and barely touched 126 mph once. And in air as good as -1,500 DA.

So either I suck at this, or my ZL1 is a slow one, or a little of both.

I'm 260 so I know it can be done. This is the main reason why I thought many others would break that 10 second barrier. I'm sure the majority of the ZL1 owners are much lighter than I am. Seat time, good track prep, and great conditions will get it done. My money is on David (17CamaroZl1) breaking into the 10.8s real soon.
From what I'm seeing though, not too many ZL1 owners race their cars at the dragstrip. "Mexico" seems to be the more popular place to race these days.