Told them I had 45 year old small block springs.Told them I would like it to sit 1 inch higher in the front.Guess what?Dead on the money!I did shim the drivers front to get rid of the existing lean to that side.I cant believe ive been running this car with those springs all these years.It actually feels like it has something decent under the front now.Arb didnt make it friday so i guess it will be tomorrow.Looking forward to that.My car just always felt sloppy and spongy.
Thumbs up to Santhuff
rats4ever
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Told them I had 45 year old small block springs.Told them I would like it to sit 1 inch higher in the front.Guess what?Dead on the money!I did shim the drivers front to get rid of the existing lean to that side.I cant believe ive been running this car with those springs all these years.It actually feels like it has something decent under the front now.Arb didnt make it friday so i guess it will be tomorrow.Looking forward to that.My car just always felt sloppy and spongy.
ROWDY has stated the same thing about the rear anti-roll bar on his Chevelle too. And I know that he puts a lot of street miles on his car. We get so used to having to deal with trade-offs and compromises with these cars in a street/strip application. It often seems that the best things for the dragstrip aren't very good for actual street driving, and vice versa.
But I guess the rear ARB is one of those rare parts in this game that actually allows us to have our cake and eat it too. Good handling on the street without having to deal with having the extra weight in the front of the car from a front anti-sway bar, and without having to remove nor even disconnect it when we go to the track. And the cool thing is that the rear ARB isn't very hard to install either. Just drill four holes in the correct locations, and bolt it on. As long as you trace the marks for the 4 holes to be drilled in the correct locations, and you use a decent drill bit that won't walk, you can't mess it up.
Headed to the shop right now to get it up off the ground and ready for install.Hope it shows up tomorrow.Sounds like a pretty simple install.Do most of ya'll use a lca relocation bracket and if so,does it make a decent improvement in traction?
I have an aftermarket rear end housing that has the upper arm mounting ears that are 1.5" taller than the stock GM 12 bolt rears have, so I don't know if I'll need any LCA relocation brackets, but just in case I do, I have the relocation brackets that UMI Performance sells.
Yes it does basically. Both methods shorten the instant center ("IC") which hits the tires harder with downforce during the starting line launch. However because the upper control arms are shorter than the lowers are, it doesn't take as much of a height difference in the mounting locations of the upper arms to change the angle of the upper arms as much as the lowers would be changed.
Because of that, it's best to be more conservative with any height changes in the upper arm mounting locations, because it's more easily overdone than height changes with the mounting locations of the lower arms. In case you don't already know this, the instant center location is represented by two imaginary lines being drawn along the upper and lower rear control arms from the sideview of the vehicle, which extend forward until both lines intersect. it's where they both intersect with one another that the instant center (IC) locations is.
The shorter the IC is (meaning the closer it is to the axles) the harder the rear tires will be hit during the launch. But there is a such thing as them being hit too hard. Because usually the harder they're hit, the duration of that downforce "hit" also tends to be shorter, and the rear suspension and the rear tires tend to be more prone to bounce back up into the body of the vehicle, and then the rear tires lose traction after the initial hit. So that can be a bad thing too if you overdo it. Then you get into having to counteract that rebound effect with rear suspension changes usually accomplished with stiffer rear springs, and double adjustable rear shock settings. Such methods are successfull at times, but you can get to a point where the IC is just too short for the power delivery of the engine udner the hood. the greater the power level, the less of a need there is for the IC to be extremely short.
But keep in mind that the factory stock rear suspension mounting locations of these cars place the IC too far forward for any power level for obtaining good straight line traction off the starting line. if the car is so underpowered that it cannot spin the rear tires anyway, ten that doesn't matter. But the more you add power to the mix, the greater need you'll have to change the rear control arm mounting locations in order to obtain straight line traction. I know that I'm really "dumbinh it down" here, but this explanation is for anyone who didn't understand these basics.
x2 on the anti roll bar. One thing Billy, I
might have missed it. Isnt the problem with the lower reloction brackets is it can put your CG too high? Basically we want the IC short but also want to keep the CG low. Thats what I always thought you were trying to expain to me. Still trying to learn.
might have missed it. Isnt the problem with the lower reloction brackets is it can put your CG too high? Basically we want the IC short but also want to keep the CG low. Thats what I always thought you were trying to expain to me. Still trying to learn.
Yep, I think you're right Del. Low and short is the ideal. How short depends on various things, ( one of them being the power level you're at) but race car chassis experts I've dealt with always told me that keeping the IC low is a desireable thing.
I think from what I've seen at the track, keeping the IC short (considerably shorter than factory stock I mean) is more important than keeping it low.The reason for my speculation on that is the fact that I went to a track last summer to watch a guy I met there run his 1970 Chevelle. The car launched what looked to me to be as hard as, if not harder than any Chevelle represented here on this board (atleast from what I could see from videoes of other cars anyway, so take that FWIW).
Out of the launches I saw that day from the driver of this car, they were all wheels up launches, and he was running 1.3 short times too with his runs in the low 10's and high 9's on 10.5" wide bias-ply stiff wall slicks.They were Transbrake launches with a TH400 trans and a 12 bolt rear with 4.10 gears. He told me everything I wanted to know about his car, and he let me take a close look at it too several times. And what he uses for the rear are the UMI relocation brackets (although I think he had thier control arms too).
But the point I want to make was that he had the rear mounting location for the lower arms in the lowest hole, and the car is nose heavy (steel hood and bumper, and tall deck iron block to boot). The upper arm mounting points were in the factory stock locations so that would place the IC kinda on the high side, and that car launched hard and straight, and their wasn't any big national event at that track of any kind that would warrant any out of the usual nor extreme track prep either. It was just another saturday at that track on that day. So atleast with his Chevelle (a heavy tank at that with full interior and all stock body parts and full weight radiator too) he did very well (and continues to do so) with an IC that has to be placed pretty high. Ofcourse there's always many variables and every car is atleast a little bit different.
My main point is that having a high IC location doesn't have to be a negative thing. It can still work although many in the know seem to agree that a low IC is the ideal and should be the goal. I just think that IC length is more important than IC height.
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Which arms did you put on the car?I am considering a set for Jr's car this year.I was looking at upper and lowers from Dick Miller Racing or Global West.
The Santhuff springs are the best in the industry BAR NONE!!!!
Vinny
Unfortunately Bob, I haven't been able to see you race the green weanie in person, but from what I've seen in the vids, your car leaves great. I can only hope that some day my car will do the same. The guy I saw in person also has Santhuff springs in the front (I had forgotten to make mention of that before).My car leaves like a cadillac Billy and still gets 1.3 short times. Everyone tells me its pretty uneventful, picks em up, sets em down, just goes
His car seems to pick em up a little higher than your car usually does (but again, I'm merely going by the majority of the vids you've often posted) but atleast for that day that I was there, it never looked out of control on the way down, and I don't believe that he broke anything. I forgot what front shocks he is using. But he is also launching off the transbrake too as compared to your choice of footbrake. So I think that the T-brake method tends to point the car's nose up a bit higher off the line.
When i first saw how high the front end of his car was rising, I thought for certain that the launch would end in parts being crunched and sparks flying out from underneath the car, but there wasn't anything like that at all, and he kept on launching the car like that too. I must say that i was rather impressed that day. I really luv watching skinny tire cars like yours and his launch like that. It isn't very often that I get to see that regardless of what track I go to around here in the east.
OK, I didn't see any great need to make mention of this earlier in this thread, but since Vinny has chimed in here, I will explain that the 70 Chevelle that I've been describing here in this thread was in fact Vinny's red one with his son Vinny jr. behind the wheel. :yes:
Best launching skinny tire Chevelle I've ever had the pleasure of watching in person. With what looked to me like one darn good driver at the wheel too!!! :thumbsup::thumbsup: I sincerely regret that I didn't bring a camcorder with me that day.
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683 Posts
Thanks Billy,The front shocks are QA1 stocker R series single adjustable.
Vinny
Vinny
No Bob, your leaves like an angry cadillac!My car leaves like a cadillac Billy and still gets 1.3 short times. Everyone tells me its pretty uneventful, picks em up, sets em down, just goes
Jakes, and my car are what you would call uneventfull.:yes:
Both in the 1.3 60fts
http://youtu.be/Au6Lq7rH9Ak
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