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

[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.

[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?

[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]

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.

[charcoal01]

One of my friends was running a 5.29 gear with a 6200 chip at cocopah. I don't know why you're stuck on this 5500 number AS EVERYONE here with experience with crates tells you 6200 is perfectly safe. When I ran an open motor at cocopah I ran a 5.67 and when I ran barona I ran a 6.20 and probably would have run more if I had the gear. I'm ona crate now, run a 5.14 and probably would run a 5.67 or .83 if I ran barona again so whoever hold you the gear isn't much different doesn't know what they're talking about.

At barona you're literally completely on the gas for about a total of 3 seconds per lap, so 1) if you do hit the chip it's going to be so short ofa time it's not going to hurt a thing and 2) if you don't have enough gear to get off the corner your whole lap is screwed up because your corner entry speed is going to be slower, your weight transfer will be less and so on, causing you more handling problems then you even realize.

You're arguing against people who know and run these cars, some with great success, some of us even run the same tracks (BTW I have multiple top 3's at your track in only a few races and was track champion in cocopah last year), learn to take advice from people with success in this sport or you'll always struggle.

Let us help you get your gearing correct for your track and then we can help you set the car up properly. Oh, the car is built with the underslung bar where it is for strength on your particular chassis, so removing it and not replacing it somewhere else will severely weaken it.

[Confused?]

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

You haven't been racing on dirt for years either. Read yourself another book about these cars. Seems to be working for you. Hopefully you may learn a little humility through this process. Only then will you be able to understand what's happening.

Enjoy your venture.....

[rob burgoon]

You haven't been racing on dirt for years either.

Wrong again. Y'all need to calm down.

Folks, if you're threatened by my asking questions and not blinding following suggestions, you should probably find another thread.

Your advice may be good, but if you say stuff that sounds like you don't know what you're talking about, I'm probably not going to follow it right away, no matter how long you've been racing.

If you can explain WHY a change would work, then I'm more inclined to take you seriously.

Rev limits and risk to engines have a potentially large impact on my budget, so I'm not likely to start taking chances there until I have the car handling well and need a torque boost.

Thanks to those that are contributing in good faith, but several of you guys need to take a deep breath and stop taking this thread so personally.

[rob burgoon]

I think it was past the end of IMCA season and those were "topless mod" non-IMCA races.

Yeah, in that video it was a lot of push then loose. Last few times it was more like "loose everywhere" in the dry. Most recently it was a little loose but kinda okish with decent tires on the back. If I had a test on friday and had to decide on changes right away, I'd probably add more bite, put new tires on the back, and see if I could mount the camera near the tach. Perhaps bring some old near bald tires to put on the back to check what wheelspin feels like.

[rob burgoon]

wow you got a weird way of trying to accomplish things that's for sure.

you can add air to the rear tires to feel wheel spin, lol.. It may take 10 psi or more on those tacky tracks if your still running that lugging gear

I just watched the under car video again. Are you guys thinking that the pulsing sound on the straights is lugging?

Most of the cars do that. Either its the rear pogo-ing or it's just bumps in the straight. You can hear it in last week's race vid.

https://www.youtube.com/watch?v=5k2C...V5H_iSmfNO8mzg

Rarrr-rarr-rarr down the straights.

[rob burgoon]

to watch you try and race, not so much...

You're safe, I wasn't in that race video. That race was shot from the stands by some guy that records all the races at barona.

[JustAddDirt]

good luck with your dirt experiment.
I have a feeling with the way you are going you will be going back to the Mazda on a road course pretty quick.
I don't care what you do either way, but when basically everyone here is telling you the same thing....change the gear, you might want to try changing it.
you can bet if I was a dirt guy going to a road course and struggling, I would be listening to as much information as possible from people that run well. Trial and error, there is no exact science to it
I will continue to watch this nice information session of a post, and see were it goes.

[rob burgoon]

good luck with your dirt experiment.
I have a feeling with the way you are going you will be going back to the Mazda on a road course pretty quick.
I don't care what you do either way, but when basically everyone here is telling you the same thing....change the gear, you might want to try changing it.
you can bet if I was a dirt guy going to a road course and struggling, I would be listening to as much information as possible from people that run well. Trial and error, there is no exact science to it
I will continue to watch this nice information session of a post, and see were it goes.

Listening, yes. Following all, no.

I believe the oldtrackchamp's suggestion about the bite was right on the money. I listened to that, liked the idea, followed it (partway), and the car got better. I will try increasing the bite further.

I also believe you guys are right about the 850 lb spring being too much. I couldn't feel the change, so I'm not shy about changing it back. I'll try that change in the second half of a test day at some point in the future, to avoid making too many changes at once.

I think you guys are right about the LR rail being too high, but that's a non trivial change. I need a pipe bender or to weld some sort of extensions to the tubes to make that happen. That, or just find a shop and write a check.

I don't think you guys are right about running a 6-6.2 rear end (at least at 5500rpm). I'm not going to drag the 6.2 gear across the garage, swap gears, pack up, drive to the track, try it, and drive back, risking the waste of a test day just because some guys on the internet say that running from 3-5k rpm will blow up my bottom end.

Much simpler to just log the tach and do the math.

Right now my car is getting better and I don't feel stuck, so I'm trying the stuff that sounds good first.

Gear changes will come later.

[Bcollins82]

The problem you are facing is that you need a setup "package" so to speak... you want to change one little thing at a time. You wont be happy with the results. And what works for one situation doesn't always work for another. Take for example your RF spring... changing it back to a 650 from an 850 right now won't help you. You have to have the "package" together with LR travel, spring rates, bar angles, weight distribution, frontend alignment and geometry, tires, and most importantly shocks. Because without the timing the correct shocks provide, its all for naught... You have people here trying to tell you FROM EXPERIENCE what works, and why. If you want to bury your head in the sand and pretend that your car is close, then that's completely up to you. But expect some backlash when someone that doesn't understand dirt cars starts asking questions without using the information being given. You can continue to try and run that car like that, but I can tell you that in 2010 I was determined I was going to make my cars fast without hiking up a ton. Just Add Dirt drove one of them... ask him how well it works... lol it seriously lacked drive and sidebite for the reasons I have given you already. I learned from my mistakes, and were all just here trying to help others that will listen. Good luck

[rob burgoon]

Asking questions should never generate backlash.

[Bcollins82]

Asking a question didn't create backlash.. arguing, disregarding the advice, and answering back with things like "you cant be serious?" probably will... lol And as far as what RRR is trying to sell you on, I hope it has a RF shock with insane low speed rebound numbers and a LR with tons of compression to help get it over on the RF and keep it there. Because with the low HP you are dealing with its already going to need help getting up and over. Thats why I put the 175 LR spring as an option, to help get the car to pop up easier. Im not saying what he's selling cant work, just that its not your "typical" chevelle clip 4 link mod spring combo. At least not in the last 10 years... The numbers I gave you arent "trick stuff" by any means. It's just a typical starting point for a chevelle clip 4 link car. If you want help further you'll have to post more info/pics...

[rob burgoon]

I see this as technical discussion. If anyone sees it as picking a fight, that's not what I'm after. I'm trying to learn the why, not just the what.

I honestly have NEVER heard of lugging ("jerk; hesitate; strain") happening in the powerband near the peak torque. I did some searches, haven't found mention of this as a thing to watch out for, except for cases of extremely wrong gearing. I asked someone smart and they suggested that there might be some kind of crazy resonance frequency thing going on with the rear axle able to rotate in these cars. I also checked video of the old alc engine running the 6.2 gear, and it pulsed down the straight too, just like most of the people I race against. Right now I honestly think the folks talking about lugging are either using lugging as hyperbole for "gearing somewhat too tall" or are trolling the new guy for giggles. Hence "you can't be serious".

But yeah, I appreciate help given in good faith, I'll post setup detail and pics later, the car is in the air right now, need to put wheels back on and get pics on the ground.

[RRR_Products]

Asking a question didn't create backlash.. arguing, disregarding the advice, and answering back with things like "you cant be serious?" probably will... lol And as far as what RRR is trying to sell you on, I hope it has a RF shock with insane low speed rebound numbers and a LR with tons of compression to help get it over on the RF and keep it there. Because with the low HP you are dealing with its already going to need help getting up and over. Thats why I put the 175 LR spring as an option, to help get the car to pop up easier. Im not saying what he's selling cant work, just that its not your "typical" chevelle clip 4 link mod spring combo. At least not in the last 10 years... The numbers I gave you arent "trick stuff" by any means. It's just a typical starting point for a chevelle clip 4 link car. If you want help further you'll have to post more info/pics...

Then the cars running the fastest times at that track must be doing it wrong.

[Bcollins82]

Then the cars running the fastest times at that track must be doing it wrong.

Sounds like there's room for improvement...

[RRR_Products]

This track is usually tacky feature time unless the 4-6 feature and usually a cushion where the heavy rf works well. Last race a 550 lf and 750 rf against a 550 550/500 ran identical times feature time. Only when the track slicks off the lighter sprung car wasn't as free to the center from entry. Otherwise most have struggled in the tacky with lighter sprung front end and being consistent was an issue. It's more of a point and shoot track that diamonding is fastest unless it slicks off feature time and no cushion. But shock valving is a huge roll in this as well. Rob on a tacky track 16.5 is front runner time and dry black slick 17.5 you're walking away. If you want to get into every detail I have the corner/section times and speeds for the set ups that have worked at this particular track. You won't find many drivers going into this kind of detail like I think you're looking for. If you recall the asphalt data logging you've done I'm sure we can relate on this subject.

[charcoal01]

Nobody that I can tell suggested a 6.2 great ratio. That is in the ball park for an open. 5.43 or 5.67 would probably get you close.

Royce, I would hardly describe that track as a point and shoot. The corners are almost as long as the straights and there is no banking. Maintaining corner speed is the name of the game there.have you actually turned any laps there?