small 1/4mile oval tips, transitioning from road racing

[rob burgoon]

It's obvious that you already have your mind made up. Keep going as you are and when you get tired of getting lapped in the first part of the feature, maybe you will listen to some of the advice on here. Remember, YOU are the one that is new to modifieds and dirt tracks, not the people trying to help you.

Haven't been a lap down in years. Nice try though.

[Confused?]

It's obvious that you already have your mind made up. Keep going as you are and when you get tired of getting lapped in the first part of the feature, maybe you will listen to some of the advice on here. Remember, YOU are the one that is new to modifieds and dirt tracks, not the people trying to help you.

[rob burgoon]

You're not taking into account the fact that lower hp generally needs more gear. You can keep believing that you only can run that 4.7 gear and you're going to keep struggling. Having an improperly geared dirt car can cause just as many issues as poor setup. Sportmod guys using 602's at cocopah run 5.14's and up and cocopah is almost twice the size of barona. You are spinning your wheels because something isn't right in your setup, you could probably get wheel spin with a set of 4.10s at that track.

My counter argument is that at 80-90% of the lap around barona in dry conditions, a 600hp engine might as well be a 350hp engine when your ability to put down power is limited by small tires and slippery conditions.

How high are your sportmods overrevving the 602? Sportmod: 6,200/5.14=1206rpm. Me: 5,500/4.7=1170rpm. So I'm in the ballpark for cocopah. When I was looking into going to cocopah last winter, a friend told me the gear change between cocopah and barona wasn't large.

Maybe I'll install my gps logger to show real mph and rpm and settle this gearing disagreement one way or the other.

But to make progress here, let's assume for the moment that my gear is too tall and I'm spinning my tires hard. Fine. So the result of a gear change is more engine braking on the rear axle, and more torque everywhere.

Neither engine braking nor some extra torque are likely to change the handling of my car dramatically. Can we focus on changes that will?

I'll take some photos of the car's suspension with it on the ground.

Regarding dropping the under tube, if you're chain limited, is the under tube just there for stiffening the rear frame rail? Any shortcuts for someone who doesn't have a pipe bender?

[rob burgoon]

I agree with charcoal01
Not to mention, lugging of an engine is worse than hitting the chip. You will probably end up spitting a rod out the side of the block, or a broken crank.

Lugging? At 3,000rpm? On a 602 crate? You can't be serious.

[JustAddDirt]

I agree with charcoal01
Not to mention, lugging of an engine is worse than hitting the chip. You will probably end up spitting a rod out the side of the block, or a broken crank.

[charcoal01]

You're not taking into account the fact that lower hp generally needs more gear. You can keep believing that you only can run that 4.7 gear and you're going to keep struggling. Having an improperly geared dirt car can cause just as many issues as poor setup. Sportmod guys using 602's at cocopah run 5.14's and up and cocopah is almost twice the size of barona. You are spinning your wheels because something isn't right in your setup, you could probably get wheel spin with a set of 4.10s at that track.

[RRR_Products]

Rob revving 5500 will be just fine. Especially on a dry night there. If the car is too tight though it may be tougher to drive on a tacky night and may struggle. Also I know what spring set up works well at your track and the valving to get you in the ball park.

[rob burgoon]

All i have to say is, don't ask questions if you aren't willing to listen to good advice. I'm done. JMO

I'm sorry you feel that way, but asking for advice does not oblige me to blindly follow all that is given.

I have several books on dirt track setup and they disagree with each other on fundamental issues. The trick with the books is figuring out who knows what they are talking about.

[oldtrackchamp4x]

All i have to say is, don't ask questions if you aren't willing to listen to good advice. JMO

[rob burgoon]

2. You need to change the gear. I have 20 + years of dirt car experience, I know when a car needs a gear change.
you can say we are talking crazy talk, that is fine if you do not want to listen, that is your choice, we are just trying to assist. You might want to go ask some front runners what gear ratios they are running. By listening to your video, the competitor's are probably in the 5.67-6.0 range. Listen to their cars, and listen to yours. big difference in RPM's, and acceleration off the corners.

I feel like there is still some sort of misunderstanding here. My competitors are running claim engines. They can rev to nearly 8,000 rpm. I am the only person in my class using a 602, and I have chosen to believe GM when they say to set your limiter at 5,500.

With a 5,500 rpm limit, of course my car is going to sound different. It should.

I reach the limiter once in a while at the end of the straight. Unless you want me bouncing off the limiter down the straight, my gearing sounds correct. If my rears are spinning (I doubt they are), won't shorter gear ratios add torque and make the wheelspin worse?

[JustAddDirt]

rob burgoon

you are asking for assistance with a car. several have chimed in to offer advise. I being one of them.
1.You have an older car that was never designed to move like newer cars do. you need to have the option to go to 5" of drop on the lr. Frame will need to be altered to accommodate that. With that being said, you are basically lifting the LR tire off the racetrack when car does roll over with side bite.

2. You need to change the gear. I have 20 + years of dirt car experience, I know when a car needs a gear change.
you can say we are talking crazy talk, that is fine if you do not want to listen, that is your choice, we are just trying to assist. You might want to go ask some front runners what gear ratios they are running. By listening to your video, the competitor's are probably in the 5.67-6.0 range. Listen to their cars, and listen to yours. big difference in RPM's, and acceleration off the corners.
3. I would suggest you ask someone local for help, that has knowledge of dirt cars, and setups. Someone there is bound to assist you. even one of the frontrunners will probably help you. Just got to ask.
4. I would suggest a chassis seminar, if available in your area.
5. If you can upload photos of what the a arm angles (low front view),and some photos of the attitude of the car just sitting there from front and back, that will help us help you as well.

[charcoal01]

I'm sorry, for some reason I always screw that up. Shorter is the direction, not taller. Just a for instance, sport mods running a 602 at cocopah run almost the same gear as the a mods running open motors do.

[rob burgoon]

Many times I've dropped my total rpm by adding a taller gear, why? Because you're able to control wheel spin better and keep tires hooked up. I went to barona with my open motor ina mod and ran a 6.2 gear. You should be in the high fives at least.

Everyone here is saying my gearing (4.7) is too tall, not too short. You're telling me I need to go taller. High fives is shorter, not taller.

[Bcollins82]

Just checked droop on LR, 3 inches of droop travel.

Thats not enough IMO... 4.5 to 5 is a good starting point. Make your limit chain adjustable, and don't just remove the underrail, replace it with one that is bent for clearance. Throw the original setup book in the garbage. Set the ride heights like I explained before, Take the spring out of the RF and cycle the suspension to be sure a 2" body shock will clear at full travel or you will junk shocks after you make the car travel. Youll probably want to add a couple degrees of camber to both sides (more pos on LF, neg on RF) since the car will roll more. Change the RF back to 650, LF to 750, LR 175 or 200, RR 225. Jbar in bottom hole on pinion, 5" of rake from center of pinion bolt to center of frame mount. A brake floater works well on this style setup if you arent using one already. Go up to 30 or 40 lbs of LR bite, add a couple percent of left side, and another percent rear. Post the rest of your full setup and include as much info as possible. Shock valving and location, bar lengths and angles, rearend square or trailing, wheel offsets, pullbar info including spring, and if possible a pic of each side the rear suspension LR pics at static and droop. There are a lot of great guys on here that will help if you are willing to give the info, and listen to what is being said.

[charcoal01]

Many times I've dropped my total rpm by adding a taller gear, why? Because you're able to control wheel spin better and keep tires hooked up. I went to barona with my open motor ina mod and ran a 6.2 gear. You should be in the high fives at least.