1/8 mile gearing?
 

My combo: 463/400rwhp/11.72/1/4,3800lbs race weight. Made peak hp right around 5400. I raced 1/8 mile for the 1st time last note, with the 3.73's I am shifting right before the traps. Seems like all the tracks are going 1/8 mile now. What kind of rear gears are you 1/8 mile racers running? Anyone have a calculator link that might help? Thanks -Jim

Jim did you run at Lagrange or reynolds.

Hey, I ran last night at Atlanta Motor speedways Friday nite drags, they run 1/8 mile. I ran at Reynolds a few weeks ago. Reynolds has Saturday braket racing(1/8) mile, I like running there but it is 110 miles one way. 1/8 mile feels strange, it just feels funny shifting to 3rd and then the race is over. I have a set of 4.10 gears I might swap in. I lost last nite to a 70's era Vette with a 502 by about a car, the 4.10's might make up that much? I found out later the guy had run in the final the week before. -Jim

BTW, I am a lot closer to lagrange, it is about 50 miles. Lagrange runs 1/8 mile too I think. -Jim

We ran my sons 81 bird a couple years ago with 1100 x 29 Hoosiers with 4.56 gears and shifted @ 5400, went throught he traps @ 5600. That's with a th350 trans and a 406. Last year we went to 5.13s and shifted @ 5800 and throught the traps @ 6100 or 6200. We picked up 2 tenths going to the 5.13s The car runs mid 7.20 with my son driving and mid to low teens with me, but 60 fts better with him. I'm putting the engine and trans in a 96 bird now, and will be using the 5.14 but going with 32" tall tires. IF I ever get it done for him.

I am runnig a TH400 w/10" Continental, stalls about 3600, solid cam, pulls well to 6000. I already have some 4.10's but I am thinking for the 1/8 I should use about 4.56's? I plan to stick with the trans/converter/28" tires for time being at least. Just looking at the situation, unless someone opens a 1/4 mile track nearby, I will be racing the 1/8th(I really prefer the 1/4). Should I try the 4.10's or buy the 4.56's? How much would be gained by going from 3.73's to 4.10's or to 4.56's? You opinions are appreciated. -Jim

If it's a track only car, I'd gear it to run the track you race at. Dought if you would see much differance going from 3.73s to 4.10s. But 4.56s are a bit much for the street. I run a 5.43 with 32" tires and a th350. I shift at 6200 and trap 6400 with my Grand Am. I broke the side out of the case last Sunday, destroyed the 9" ring and pinion. I'm going back with a 5.67 or a 6.00 and a pro case this time. Haven't made up my mind yet

DiamondJim, In the September 15, 2006 issue of DRM (IHRA mag), there is a chart that gives a conversion of 1/4 mile to 1/8 mile gear ratios for maximum performance. It doesn't list 3.73s, but it does list 3.70, and it says the best replacement for the 1/8 would be 4.63. If I were you, I would go for the 4.56s or, if you want to press it, 4.88s.

Thanks WD, I was already leaning toward the 4.56's. Now for the next question, for my low hp car which gear set should I use? I have been running Richmond street gears and they are the cheapest(165 at Summit) but I see US Strange has what they call Pro Street gears for 238 bucks, OR should I upgrade to the Pro Gear? The Strange gears say they are 8620 steel but the Richmond doesn't say what it is. Thanks -Jim

I ran richmond 4.56 street gears in a 8.5 10 bolt, with 29x1100 hoosiers with no problems. But I have also seen guys destroy 8.5s and 12 bolts. Depends on how they are setup. My biggest problem was axles. The case on my ford 9" let go last Sunday, not the pinion support. So they can all break. I would go with the 4.56s also.

I have Moser axles, tubes welded to housing, Ford bolt on ends. I am running Richmond street 3.73's now, that is probably what I will get for the 4.56's, unless the US Strange would be a lot stronger. -Jim

racing gears are made from a softer material to handle the sudden shock of taking off the street gears are made of a more durable material for long life (harder) , we use a set of 4:56 richmonds street gears in our 8.5 housing( T/A girdled) under a 3500 pound car with 650 hp big block other brand motor launching at 35-4200 off a trans brake and they lasted 4 years ( till someone decided to change the yoke out and didn't replace the crush sleeve) I would call US gear and see what they recommend .

gearing
 

Jim,
Unless you are loking for optimum performance, I wouldn't change the gears. If you are going to bracket race it doesn't matter as long as you are consistent. I won yesterday running 7.82 - 7.86 for 7 rounds with 1.77-1.78 60's on a hot track all day. Just find a set up the car likes and will be consistent with. I run 3.73 gears behind a 406 in a 3400 # car, shifting at 5200-5400, and I shift into 3rd gear at about 500' or so, hard to tell cause by the time I am there I am looking for the other guy.:heh:
Mel

Thanks Mel. The Friday Nite Drags deal is run heads up 1/8, that is the reason I am considering the gear change. I lost last Friday(by about a car) to a guy that ran in the championship. It is kind of goofy but fun, the starter drops his hands like Pinks! The race is run on the pit road at Atlanta Motor Speedway. I am running Domestic, (Mufflers/etc). There is a Hemi Dart there that is fast, the guy that beat me has a 502 Vette. Also the next 2 closest strips to me have gone 1/8 mile, I really don't drive my car more than a few miles on the road, so the gear change will be OK. -Jim

And oh yea, CONGRATULATIONS ON YOUR WIN!!! -Jim

Street Drags
 

Jim,
Thanks! We run the street drags the same way on Tues. nights. I went out one time and ran. It is fun, we do ours off the flag also with 6 heads up classes, including bikes. I mainly went out to let my son ride with me down the track, we made two nitrous passes. On one of the nitrous passes we ran a friend of his in a late model SS Camaro, and pulled him by about 300'. My son really got a kick out of that and we had a good time. Going to steeper gears may also create traction issues. Either way the main thing is to have fun and enjoy your car!
Mel

Thanks Mel, traction will be next, I was spinning out of the hole Friday already, lowered my MTETDR's to 16 lbs and did a John Force crowd pleaser burnout and hooked pretty good. Only 3 trips to the track and the tires tread are about 1/2 gone! I am running 2 air bags/no-hops/HO Racing rear sway bar/adjustable uppers, etc. I will probably install an anti-roll bar this winter and remove the sway bar. The guy with the 502 Vette that beat me told me he had 5000 in suspension mods so my changes are a bargain-LOL. I hung with him all the way down the track, the 4.56's should leave him in my mirror(I hope). I sure wish I had installed a 9" rear, all this gear changing stuff would have been a piece of cake! Oh well, live and learn. Have a GREAT day! -Jim

Jim, what ET and MPH are you running with the current combination? I've went 7.20's at 95 mph on our local 1/8th mile track. Just happend to be pitted beside a guy running a gutted out Nova with a high compression 454, 4.56 gears, loose converter, etc, and he was only running 7.10's at 93mph. He liked to crapped himself when he wandered over and found out we were running a pump gas 455, q-jet/iron intake, full exhaust, 3.42's and a tigtht 10" converter......and DOT's!

I really don't think you'll pick up much with the taller gearing, and it could make the car even harder to hook? Then of course, you'll really be revving hard when you find your way to a 1/4 mile track......Cliff

Cliff, no 1/4 mile tracks left around here. You can run sportsman at one but it stops at 12.0. Usually run 7.30's/7.40's in 1/8 at 93 or so. There are some really fast cars hooking the MT's I am running, we shall see. I am saving my 3.73's, I will have 3.73's,4.10's and 4.56's, (4 series carrier). If we had a good 1/4 mile track I would get a 3 series carrier and run 3.42's but the 1/4 mile tracks are disappearing! I can run the Friday nite deal and then run Sat afternoon if I feel like it, both 1/8 mile. I know my suspension will have to work to pull this off, we shall see. I almost feel like putting in 3.23's or 3.42's and test your Powerglide theory! BTW, do you shift to 3rd in the 1/8? My 2/3 shift is about 200 ft before the end. Thanks -Jim

I agree with Cliff on this - I changed to a 4.10 from a 3.73 for the 1/8th mile stuff and slowed down a small bit... The car likes to torque it's way down the track, since we also have a great 1/4 mile track nearby I am going back to the 3.73 because I think it will run better on both tracks...

3.23-4.10 got my 60 ft times down from mid 1.80's to mid 1.60's a later change to 4.56's brought me down to 1.52 best (and more consistant) 60 fts. 4.56's cost me mph in the quarter over 3.23 or 4.10's.(a 29.5- 30" tire would have helped lots) I was running McCreary(now American Racer) soft compound "DOT" dirt track tires 285/60-15(about 28.5" diameter @11" tread) I drove the 4.56's to the track(40+ miles one way) on the back roads and at 55 mph was a bit annoying(My 100 watt stereo sounded like a transistor radio) but mileage was about the same. The biggest portion of my 1/4 mile gains were in the eigth mile. I'll see if I can find my notes for actual #s and post them.

"BTW, do you shift to 3rd in the 1/8?"

Yep, it really doesn't matter when I shift into 3rd gear. I can actually bypass 2nd gear completely and it has very little effect on ET/MPH. Typically for bracket racing I'll shift around 5000rpm's, even though the engine pulls strong to at least 5800rpms (rev limiter).

The real key to running quick is the launch. Have you ever watched a Pro Stock car make a perfect launch, then break something a couple hundred feet out......and COAST thru in the low 11's at about 100mph!......Cliff

Yea, it is kind of depressing to watch the Pros break 200 feet out and still run a better time than I do-LOL. I know a few guys with combos similar to mine(but lower gearing) pulling 1.5X's 60's to my mid 1.6's. I also know I have my work cut out for me! -Jim

Jim, over the past few years I've widdled 60' times from 1.90-2.0's down to 1.60 to 1.67. For my car, the tires make more difference than anything else. I've tried all sorts of traction devices, welded in sub-frame connectors, added drag shocks, removed the front sway bar, installed an adjustable pinion snubber, etc. The tires are the KEY to hooking up, no doubt about it. If the tires don't try to bite, all the bolt on devices in the world ain't gonna help. As I kept getting better tires, we immediately saw improvements in traction, and 60' times, THEN I could fine tune the traction devices to even further improve 60' times.

The reason that I have so much trouble is that we hit the tires with near 600ft lbs torque, and only have room for tires with about 9" of tread, 27-28" tall. A set of 12" wide tires would quickly improve everything, but I refuse to jack the car up, or start hacking away at it, to get them to fit. I also LOVE the stock look, and refuse to have a bunch of junk hanging under my car. I'm trying to keep the "stock" look, and go really fast, which has proven to be quite a challenge......but we are making good progress!......Cliff

one question? what the tread on those dirt track tires look like after a run they should look like 1000 grit sandpaper across the tire you might have too soft a tire .

Stimpy, me? BTW, hows Ren? I used to watch Ren and Stimpy with my children, loved the show. Cliff, not much more I can do but move to the anti-roll bar. On the front I have stock worn out springs,I have removed the front sway bar and put on 90/10's, on the rear I have Lakewood No-Hops and boxed lowers, adjustable uppers preset per Dick Miller Racing, air bags(10 left/15right), Lakewood 50/50 drag shocks on rear, 275/60/15 MTETDR's. Depending on track prep and who I run after, I can hook pretty good. -Jim

Stimpy the first set I ever used there was no compound choice. The second set I was given a choice and chose soft. My burnout was reduced to a light hazing of the tires to clean them then stage immediately. Had no issues but had to run rim screws or tire would slip 1/2 turn. Even though they werent wrinkle wall slicks they did "wrinkle". Bias ply tire very light 13-14 psi for my combo. 20 psi more comfortable on highway. Got a couple thousand miles out of a set. http://www.americanraceronline.com/
Download catalog and See catalog page 6 for tire sizes tread pattern GG on page 8 was what I was using. Guy that bought my car switched to 275/60 ET streets and never hooked anywhere near the McCreary's. He since tubbed the car 4 link etc. MT street pros(big) not 60 footin significantly better for the money he's tied up.

Jim, we've ran quite well on the MT Drag Radials, but they require WAY too much burnout for my liking, and are slam worn out. I check them closely today when I bolted in the new Mosier axles, and they are GONE. No cords showing yet, but they are thin. Some say they work better once the tread is gone, we'll find out this Friday?

I may be buying tires next weekend at Norwalk. I'm going back to the bias ply version. They weren't nearly as stable on top end, but required little if any burnout, and lasted over 3 seasons. The radials are gone after half a dozen outings....but they did serve us quite well, we won most the races we entered with them.......Cliff

The McCrearys were very inexpensive compared to the other brands. Dont know how the prices compare since they became American Racer. If they are still around when I finish my project they will likely be a tire choice if their prices are reasonable.

They are still around and very affordable. I went from 1.92 60's to a 1.71 with the change of tires from a 295/65/15 BRG Drag radial to a 280/60/15 tire. I run 4.10 gears and have gone 11.65 with just slapper bars with my old motor.

Robert

I was sixty footin 1.52's with the 285/60-15's only 11.70's though due to 4.56 gears being out of rpm way before the lights and on the 6800 rev limiter a few hundred feet. I liked those tires. Got introduced to them at a dirt track and noticed how hard they were hitting the throttle and not spinning on dirt. Got me thinking if you can hook up that good on dirt how good would they be on concrete. I found out. Back when I bought my last set about 10 years ago they were only $100.00 a piece with tax. Wonder what they go for now?

Why not put more converter in it?

I race half track 90% of the time, but 1/4 mile racing is what my car is geared for...

I knew of them during my street racing days in the late 80s and early 90s. Alot of fast cars on the street were using MCCrearys and I remembered them. I picked mine up last year for about $125. Still a very good deal for what they do.

I never quite got my car dialed in and got to run the 1/4, but I think I would have gone low 11s as my car was running the 1/8 in 7.71 at 92mph. That is a full 3/10s faster in the 1/8 than what my fastest 1/8 mile time was when I ran an 11.65 in the 1/4.

Robert

You know, I thought about that. I can buy the gears/install kit and have them swapped for 435 bucks. All 3 places around here that bracket race (Atlanta Dragway, Silver Dollar, Atlanta motor Speedway) are all 1/8 now. I trailer my car anyway now because it is just too hot to drive a Black car with no A/C on a 3 hour round trip. A good converter alone is more than I will have in swapping the gears, plus I would have to spend most of a Saturday installing the converter(or pay someone). I am saving my 3.73's for the future. I am anxious to see how this works out. -Jim

The 4.56's will help you dodge the golf carts easier when your driving around Peachtree too. Loose convertor might lead to overheating if you get caught in traffic. (In 1980 there was no traffic there, sure has changed over the years, glad I never accepted a few job ops there.)

Hey Bruce, sounds like you know the place. 1980? You wouldn't recognize it now, I think there are more golf carts than people and more police officers than carts-LOL. I usually go over near you to get away from it all(Lake Guntersville), I had an aunt in Franklin Tenn., use to fish that whole area. You a big orange fan? -Jim

The kids are orange fans I have no allegience to sports teams. I was in your neighborhood about 15 months ago. I've been there frequently over the years. Sure has changed. I work for Pitney Bowes taught quite a few classes down there over the years as a field instructor. Was a time when you had 1 bar there. People new me by name and what I was going to order. I remember when you HAD to go thru Tyrone to get there. Yeah it sure has changed.