Who's right

[pontiacgp]

We tested the race car last nite and ran 6.00 rear gears. Had great lap times but the owner/crew chief thinks we hit the 6400 chip too soon and wants to switch out the gears to a 5.83. That should drop the revs by about 150 but I say leave the 600 in and run a 1/2" larger rear tires with a 2.75 stagger, there is not much banking at this track. I think the car will do better in traffic and restarts with the 6.00 but the rest of the team seems intend to try the 5.83 at practice on race day and see what we get. My money is on the 6.00..... 🙂

and it's nice of the track to have our car on it's website to advertise the race....

http://flamborospeedway.net/

 

[mac61891]

I read your post and have had a guy in my home town ask me similar questions about his race cars even though, I have very very little race experience. He was refered to me by a racer that I think just wanted him gone. I don't know. But, I thought I might weigh in anyway. The change the owner is talking about is about 3% gear change as you already know. The tire change that you are suggesting would offer about a 2% overall gear change. The car would be slightly faster with the rear change which is what he wants. Your change would be slightly slower, but have just a touch more pull in restarts. It works out to such a small amount, that with traffic, you may not notice. So, I guess, honestly, you are both right to some extent. Your stagger change would make it turn in better, hands down.

 

[pontiacgp]

You're about right with your calculations. The track is 3/8 mile and not much of an outside groove so my thinking is if we are stuck on the outside we'll be quicker out of the corner and should be able to get back down on the straight. If we are in front even if someone has a little more speed it won't be enough to get by us. Funny thing is we ran this car last year with the 6.00 gears and it never hit the chip like it did last night. We ran this track for a few years in the thunder car class so we know the track. We had the thunder set up with light springs big bar and the car could go deep into a turn on the outside and pass a few cars just entering the corner..

 

[Randy_W]

From years of racing karts, a few hundred laps in my Firebird road racer and a lot of boat racing I made this observation. All things being equal, a vehicle will almost always be more efficient with bigger gears and bigger tires/props than the other way around. So I agree with you.

 

[pontiacgp]

thanks for your input Randy and even more so for agreeing with me... 🙂

feel free to hijack the thread with pictures of your karts, firebird and race boats...

 

[Fox80]

After 16 years of circle track this caught my eye, on dirt we always had similar debates, the track I ran last year was a high bank, high speed 1/2 mile. The common gear was a 6.00, if I ran a 6.50 I would hit the 8,200 chip at the end of the straights when the track was heavy and fast, but once the slick came in I would rarely hit it, but on restarts and off corners I was far faster than the rest of the lower gear guys. Running on the chip is not hard on a motor, and can be used as a tuning tool, I broke a five year old track record by changing the chip to 8,500 for a perfect track when I started on the pole. With 12 wins last year out of 15 nights I say I'm right more gear always works better, lol imo

 

[woody31]

i would run a steeper gear vs a tire stagger change,,,any day of the week,,you can always adjust to track conditions with your right foot,,,either no chip or a 8750 chip,,have turned a i,m,c,a, motor over 7000 with a 650 gear,,,good luck with your ride,,looks nice,,,

 

[pontiacgp]

thanks...but if you start adjusting with the right foot a 100 laps is rough on the driver and it burns the tires. Plus this is a fast division and you can't play like that and expect to win. Currently we have a 3.25 stagger and there is no chirping but I think less of a stagger will plant the car better coming out of the without tightening it to much much in the center of the corner. The other problem is we test in the nice heat of the afternoon but we race at night so the car is always tighter during the race. We have to get it right cause there are no pit stops so we lose our position if we come in under a yellow or green. As far as the chip goes we rung a sealed 604 crate so there is no advantage to run a chip higher than 6400 and we don't have a budget to replacing blown engines

 

[Randy_W]

double post

 

[Randy_W]

I can't speak much to stagger as most of my 4 wheel racing was on road type courses, used it a little in karting. But I can say with little reservation that using bigger number gears and taller tires gains you efficiency vs shorter both. As an example, my Z29 Donzi running twin 540's gained 4 mph by switching from 1.32 drive gears to 1.5, even running the same props! With a prop tune we gained 7 miles an hour on the straights in brackish water. That's an 8500 lb offshore boat.