Went to the drag strip

[Blackbelt]

Took my 91 to Fontana 1/4 mile drag racing track 2 times in the last month. Best of 12.5 @ 113. Wondering if 4.10s will help me drop some time?

Also what's best some has gotten these things to 60ft on regular street tires? I was having a heck of a time trying to get this car to 60ft

[WARP TEN]

Took my 91 to Fontana 1/4 mile drag racing track 2 times in the last month. Best of 12.5 @ 113. Wondering if 4.10s will help me drop some time?

Also what's best some has gotten these things to 60ft on regular street tires? I was having a heck of a time trying to get this car to 60ft

There has been a lot of discussion about the question of 4.10s vs. 3.45s in drag racing. I would simply suggest that as a general matter, the slightly quicker acceleration of the 4.10s is probably more or less offset by the need to shift into fourth gear with them. With the 3.45s you can get through the 1/4 mile in third. But I loved the 4.10s on the street around town. BTW, 12.5/113 is a great time suggesting you have some performance modifications on your car. My '95 with Haibeck's 510 package and a 4.10 ran a 12.4/116 at Beech Bend with Marc driving it and no power shifting. When I drove it was slower. Below is a picture of me racing Marc's '93 then (photo courtesy of Gunny). Needless to say, he won.

As to 60 ft times, Marc always said the best way to get off the line quickly was to bog it a bit at first, launching around 1600-2000 rpm as I recall. I'm sure there will be other sound opinions on that here as well.--Bob

[Blackbelt]

Thanks Bob. I am happy with the performance of it. I'm thinking 4.10s, aluminum flywheel and some drag radials and I can get at least some 12.3s out of her if not a little more. One of the runs I trapped 116 but it was slower run.

Car has porting, headers, exhaust and chip. Would love to get heads ported one day. For what it is it runs really strong.

Best 60 foot I could get was 2.0 I really think street drag radial would allow me to better that and get faster runs as she sits. I'll try soon.

[jss06c6]

My experience in my 2006 Z-51 was that MT Drag Radials took almost a second off my 1/4 mile time. Best I could do putting 428 HP to the pavement on street tires was 12.85 at 117. Could never get below 1.95 60 foot time. Changed to MT's and immediately ran a 12.02 123 and 1.72 60 foot. Ran 17 lbs in the MT's. Six speed manual.

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[BYEBYE2U]

4.10 n even 4.33 will slow down the tires enough to hook easier....n multiply the car's power accordingly
I could not come out higher than 2500 rpm without hazing my Good Year F1s on my bone stock 95Z
My 65 Supercharged Chevelle LOVES BIG GEARS :)

[Ccmano]

There has been a lot of discussion about the question of 4.10s vs. 3.45s in drag racing. I would simply suggest that as a general matter, the slightly quicker acceleration of the 4.10s is probably more or less offset by the need to shift into fourth gear with them. With the 3.45s you can get through the 1/4 mile in third. But I loved the 4.10s on the street around town. BTW, 12.5/113 is a great time suggesting you have some performance modifications on your car. My '95 with Haibeck's 510 package and a 4.10 ran a 12.4/116 at Beech Bend with Marc driving it and no power shifting. When I drove it was slower. Below is a picture of me racing Marc's '93 then (photo courtesy of Gunny). Needless to say, he won.

As to 60 ft times, Marc always said the best way to get off the line quickly was to bog it a bit at first, launching around 1600-2000 rpm as I recall. I'm sure there will be other sound opinions on that here as well.--Bob


Bob, Reading many of your recent posts, I’m starting to get the impression you are really pinning to get back into a ZR-1. C7 Z06’s like yours are amazing cars as are the 2 C6 Z51’s I’ve had since my first ZR-1. They just seem to lack the soul that the ZR-1 has. One of those things that’s hard to quantify. Do you think you will ever do it?
H
:cheers:

[Bob Eyres]

Blackbelt- I'd say you were doing pretty good. Others may differ, but I think at least 4.10 gears is the way to go in the 1/4 mi. (and on the street).
Your thinking on drag radials, gears, light flywheel is correct. It will give you at least half a second in the quarter with the mods you already have.
The thinking that you can "cut a better time using stock gears, and only use three gears in the quarter" is incorrect. Did you ever see or hear of a drag racer with a four speed put a lower numerical rear gear in, so that he only had to shift twice at the drag strip to "save time". That's silly.

Dissect your best numbers. #1 - You've cut a 2.0 60ft. on street tires, so you know how to drive. #2 - Your car will trap at 116mph, which means it has around 425hp. at the crank. #3 - Your best run of 12.50 with street tires and stock gears tells me that with the above equipment, and practice to put these numbers together you're in the elevens. :dancing

Your porting is ok, but the heads are where the power is. (witness Haibeck's 510hp- 350c.i. cars and Pete "the Greek", banging on the tens with a stock block 350 c.i. car.) It's the way this puppy breathes.

I've never cut an eleven second time, and that's mostly because my engine is stock, no porting, only bolt-ons (see below).

Good Luck, and wait for a cool night. They love the cold air. :eek:

[mike100]

Former owner of #1673...The Watson headers with the longer primaries may have cut faster trap speeds than the OBX mid length units you are running now....I forgot to bring that up when we were brainstorming earlier...also maybe gps check the speedo accuracy at higher speeds and raise the rev limiter accordingly if it can't get thru the 1/4 without hitting the cutoff. I think the GY tires are shorter than the oem gatorbacks diameter-wise.

But as also discussed, this particular LT5 seems to have cam timing that is strong in the mid range punch compared to others I have driven that feel top-endy...no two are alike.

[gtcollins@maxnet.co.nz]

Hi here is couple of time slips from some racing I have done this year the road tires race I was leaving the line at 4000 rpm I slip the clutch as I don't want to break a axle the track is very well prepared and I get no wheel spin when l heat the tires they get traction and push the car forward while pushing on the brake pedal
V
The other time slip is from another track and I am using Hoosier quick time drag radials when I heat the tires they spin and don't push the car forward on take of the tires spun up and the back went side ways before taking of 12.56 is my best time so far I'm still learning how to get the car of the line I have made the injector bosses small I haven't removed them completely I also have a aluminum flywheel and headers which I made I hope this helps 72907291

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[WARP TEN]

Bob, Reading many of your recent posts, I’m starting to get the impression you are really pinning to get back into a ZR-1. C7 Z06’s like yours are amazing cars as are the 2 C6 Z51’s I’ve had since my first ZR-1. They just seem to lack the soul that the ZR-1 has. One of those things that’s hard to quantify. Do you think you will ever do it?
H
:cheers:

Hans, you are right that the ZR-1 has soul, and I do miss them. Every time I go to a Corvette show I think about the ZR-1. My new Z06 is beautiful, very fast (GM's numbers say 0-60 in 2.95 seconds), a great car to drive on long trips or around town and the technology improvement over our '80s-based technology is enjoyable. But the '95 was very special, one of the last built in the last year of production, and quite rare--with attrition, probably one of only 400 or so '95 ZR-1s left in the world. There was rarely another one at the shows. And it really had the best looking engine I have ever owned in an American car. I often won best in class trophies. So yes, I do miss the car in many ways. Unfortunately, at this stage in my life I have only enough room for one toy car in my garage--and not much of that, as it is a two car garage with a lift. In my dreams...Bob

[rush91]

Every time I go to a Corvette show I think about the ZR-1. My new Z06 is beautiful, very fast (GM's numbers say 0-60 in 2.95 seconds), a great car to drive on long trips or around town and the technology improvement over our '80s-based technology is enjoyable. But the '95 was very special, one of the last built in the last year of production, and quite rare--with attrition, probably one of only 400 or so '95 ZR-1s left in the world. There was rarely another one at the shows. And it really had the best looking engine I have ever owned in an American car. I often won best in class trophies. So yes, I do miss the car in many ways. Unfortunately, at this stage in my life I have only enough room for one toy car in my garage--and not much of that, as it is a two car garage with a lift. In my dreams...BobAll you have to do is sell one of those BMWs lol.....then it's a 2 Corvette garage! I never see any Z's in my area, and I love it :)

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[WARP TEN]

All you have to do is sell one of those BMWs lol.....then it's a 2 Corvette garage! I never see any Z's in my area, and I love it :)

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Sorry, can't sell mine--Corvettes don't do too well in a foot of snow. If I sold my wife's there probably would be more room as I would very quickly find myself single. But with lots of extra expenses. :eek: --Bob

[Paul Workman]

Blackbelt- I'd say you were doing pretty good. Others may differ, but I think at least 4.10 gears is the way to go in the 1/4 mi. (and on the street).
Your thinking on drag radials, gears, light flywheel is correct. It will give you at least half a second in the quarter with the mods you already have.
The thinking that you can "cut a better time using stock gears, and only use three gears in the quarter" is incorrect. Did you ever see or hear of a drag racer with a four speed put a lower numerical rear gear in, so that he only had to shift twice at the drag strip to "save time". That's silly.

Dissect your best numbers. #1 - You've cut a 2.0 60ft. on street tires, so you know how to drive. #2 - Your car will trap at 116mph, which means it has around 425hp. at the crank. #3 - Your best run of 12.50 with street tires and stock gears tells me that with the above equipment, and practice to put these numbers together you're in the elevens. :dancing

Your porting is ok, but the heads are where the power is. (witness Haibeck's 510hp- 350c.i. cars and Pete "the Greek", banging on the tens with a stock block 350 c.i. car.) It's the way this puppy breathes.

I've never cut an eleven second time, and that's mostly because my engine is stock, no porting, only bolt-ons (see below).

Good Luck, and wait for a cool night. They love the cold air. :eek:

Agreeing w/ you Bob, from personal one-on-one experience drag racing YOU!

Or motors were comparable; both in the "510" range, but you had pulled about 2 car lengths @ the quarter. BUT! That said, you were loosing ground quickly in the second 1/4 mile (WANNAGOFAST) 1/2 mi. run.

I ended the 1/2 mile at ~144.25 (IIRC) in 4th gear, and you crossed the 1/2 mile at 138.xx as I recall. (However, you did had enough lead to finish ahead of me at the half mile mark.

I concluded from that, that beyond 1/4 mile the taller gears take over. And, Pete's numbers seemed to agree.

Ami's car has 4.10s and cams. There's no doubt it rips around the highways and byways with more authority. But, I always feel I need to be shifting (again, and again) or else constantly winding it out.

I'm not as hot to trot for 410s as I once was. But, maybe 373s or 390s???

[Hog]

Just felt like crunching numbers.
3.45 gears at 2000rpm in 4th is 44.8mph or 91.5mph in 6th

Going to 3.73's from stock only raises rpm by:
150rpm in 4th gear(1:1), 2000rpm is 91.5mph in 6th
3.90's raises it by 250rpm in 4th, 2160rpm is 91.4mph in 6th
4.10's by 375rpm in 4th, 2260rpm makes 91.5mph in 6th
4.30's by 500rpm in 4th, 2490rpm is 91.4mph
4.56's by 645rpm in 4th, 2645rpm is 91.5mph,

6000rpm nets:
With stock 3.45:1 gears
50.2mph in 1st, 74.7 in 2nd, 104.3mph in 3rd, 134.5mph in 4th, 179.4mph in 5th and 272.5mph in 6th

with 4.56 gears
40mph in 1st(2.68:1), 56.5mph in 2nd(1.80:1), 78.9mph in 3rd(1.29:1) 101.7mph in 4th, 135.7 in 5th(0.75:1) or 207.7mph in 6th(0.49:1)

If you get low enough rear gearing, you can 1st to 3rd shift or 2nd to 4th without getting the sensation of lugging so much. The factory wanted the LT5s to be shifting from 1st to 4th directly under light throttle. Bah!

If doing a gear swap, you certainly want to be able to tell a difference. I wouldn't go any higher than a 3.90:1 from the stock 3.45:1 ratio, but probably not and lower than the 4.10 on a driver. The more aggressive the cams/higher peak power rpm, the lower the gear IMO. Of course rear tire height will also have to be factored in.

That ZF-6 allows you to have cake and eat it too! Great trans.

[Pete]

Hi
Just a couple things i notice on your timeslips.
You are hauling butt second half you are picking up 30 MPH from 1/8 to 1/4.
Are you short shifting 1st and 2nd gears?
I think with the mods you have you should be running closer to 88-90 MPH in the 1/8.
I tried 4.10's i did get better 60ft but whatever i gained at 60 ft i lost with the extra shift.
I prefer 3.45's because i like my highway.
4.10's are fun if you like to blaze the tires at will.
I would rather loose a tenth on 60 ft and keep my MPH most races on the street are from a roll MPH will always win.:cheers:

Pete




Hi here is couple of time slips from some racing I have done this year the road tires race I was leaving the line at 4000 rpm I slip the clutch as I don't want to break a axle the track is very well prepared and I get no wheel spin when l heat the tires they get traction and push the car forward while pushing on the brake pedal
V
The other time slip is from another track and I am using Hoosier quick time drag radials when I heat the tires they spin and don't push the car forward on take of the tires spun up and the back went side ways before taking of 12.56 is my best time so far I'm still learning how to get the car of the line I have made the injector bosses small I haven't removed them completely I also have a aluminum flywheel and headers which I made I hope this helps 72907291

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[gtcollins@maxnet.co.nz]

Hi I'm changing at 6500 rpm the only mods I have is chip injector bosses trimmed down aluminum flywheel and headers which I made next season I will try changing gears at different rpm levels

Thanks for the reply I would like to get the times down to 12.3
Regards Glen

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[Blackbelt]

Lots of good stuff guys! Long term I'd love to get the heads ported and get some upgraded cams.

Short term I'm gonna try getting a stickier tire on the car. My question is what are you drag guys running for wheel / tire combos? I'd imagine a drag pack with the correct offset for our cars is kinda rare?

Can I just grab a 17 x 11 a mold reproduction wheel.and run a drag radial on it? How stupid will that look on our car? Any suggestions would help. If prefer to have separate wheel set up for the rears at least so I'm not breaking down wheel & tires all the time.

[gtcollins@maxnet.co.nz]

Hi I am running a molds and Hoosier 315 35 17 tires here's a photo of the car with the tires on it

Regards Glen 7298

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[Pete]

Next time try 6900/7000 and keep an eye on your MPH in the 1/8.
Lets us know the outcome.
Is your Tech/RPM correct?

Pete




Hi I'm changing at 6500 rpm the only mods I have is chip injector bosses trimmed down aluminum flywheel and headers which I made next season I will try changing gears at different rpm levels

Thanks for the reply I would like to get the times down to 12.3
Regards Glen

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[gtcollins@maxnet.co.nz]

Hi Pete our racing season is over so I will have to wait until next season starts to try changing gears at a higher rpm thanks for the input
Regards Glen

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