So by now, most everyone here knows that I'm planning to drive my street/strip car out to Bonneville for the USFRAs World of Speed event in September. I'll be trying for the 130 MPH Club and if that goes well, we'll take a shot at the 150 MPH Club (details at "Help support the Bonneville dream T-shirts" thread, in the classifieds)... I've been there many times - mostly as a crew member on the #151 Salt 'n' Peppers Nash (built by Vern Tardel and Ron Fry). That car was powered by a blown injected flathead on alky - since it was blown, it didn't care about atmospheric pressure. My carbureted car, on the other hand, will need some tuning to run at Bonnevilles 4,000' altitude - where the corrected altitude can exceed 7,000'! I live at 1,200'. So question one is: 1. Once I get my new engine dialed in at 1,200', what's the general rule of thumb for jetting and timing at higher elevations - Bonneville, in particular? I know there's a few old salts on here, plus lots of Colorado guys - how 'bout it? Suspension tuning is another concern. Mine works fine on asphalt at 127-130 MPH, but salt is so different - when I drove the Nash at B-ville, I found slippery "slushy" spots, dry "frictiony" spots (that slowed the car dramatically), and some gnarly ruts that really tossed the car around. Here's what I'm working with: 2"X4" mild steel frame, with 10 point 'cage. 86" wheelbase. Front suspension is Opel GT (Corvette style IFS, w/ cross spring), with 90/10 3-way adjustable shocks. Car has an iron smallblock up front, so is nose heavy. Rear suspension is utility trailer parallel leafs, with front halves bolted together, a pinion snubber and 50/50 shocks (I'm currently fabbing an anti-roll bar). Rear tires are 10" wide Z-rated Yokohamas - fronts are 5" versions of same. I'm planning on adding some (removeable) weight to the bottom edge of the framerails. Other than that, I'm clueless on approaching the suspension tune-up. Remember, I come from a street/strip background. So: 2. What am I overlooking on the suspension set-up? Maybe you can tell - I'm having an absolute blast preparing for this deal!Which brings us to our final question: 3. Why aren't more people doing this?! The salt flats aren't going to be hosting speed events much longer, the way things are going. I can't believe the BLM and the salt companies ever allowed it in the first place, but nowdays..... So I'm gonna try again this year (went in '96 and got rained out), just so I can say I ran my car at the Bonneville salt flats. A lot of my heroes ran there, too... Thanks in advance for any advice you guys can share with me. And I'll do my best to pass it on... Scotty
The biggest thing that stands out is the 90/10 shocks. If they are true 90/10 shocks they are made to get the front end up in the air quickly hold it up in the air as long as possible. That is not a good thing for high speed runs. The other thing I would check is weight distribution. What are your individual corner weights, front percentage, side percentage, and cross percentage?
Thanks, Racyredhd. Front shocks are 3-way adjustable - right now, they're set on 90/10. Before hitting the road to B-ville, I'll change 'em - I can choose from 50/50 (sounds like the logical choice) or 60/40. I haven't scaled the car. Don't know anyone with scales and frankly, wouldn't know what to do with the info. Any suggestions?
I would think that you would want to run the shocks a 50/50 to keep the car stable. things happen fast in a short wheel base car. If you really want the car set on kill you would get some Penske or Ohlens shocks and get them set up to actually hold the car down on the suspension. That way you get the air from getting trapped under the car. As far as scaling the car get the car just as it would go down the track, driver and fuel included. You will want to get as close as possible to 50/50 left to right, and around 52-53 percent front, and the same on cross weight (LR + RF as a percentage of total car weight) to make sure nothing is bound up. Make sure your frame heights are the same left to right. You probably already have the nose down a bit. If not already,you will want the nose down. What you are trying to do is make sure that you havent jacked you frame and suspension out of whack getting your corner weights right.
Thanks. Plenty to think about here. You know, I worked as a chassis fabricator for years, but just built knuckledraggers that never had this much thought put into them. It's about time I stepped up and made sure the car has every chance of doing what I want it to do, eh? I'll start networking to find a set of scales I might borrow and use them to tell me where I really need to put the new weight - better than crossing my fingers and using the dartboard...Hey, get me: I'm already inspired, on the first reply to this thread! O/T UPDATE: Just got my shirts in the mail! Nate did a great job - they look great and showed up on time and everything. To all who bought one - thank you so much! You guys are all salt heroes! To Nate: You sir, are a ruler!
From one knuckledragger to another, I might not ever make it to the salt, but thanks to you I do have a crew shirt. Good luck. Find some 10.5 tire guys they're always scaling their cars.
Hey Dave - Thanks for buying a shirt! I hope it goes for a hair raising ride this summer in your race car! If nothing else, it oughta make for a decent pit rag... Um, yeah - I'm just thinking of who I can hit up for scales...If nothing else, I'll be at the track this weekend and am bound to run into someone there. Kinda embarassed that I've never done that before, but better late than never, right?
I know about Speed Week and World Finals but what is the september event at Bonneville? Is there a website to learn more? Thanks, [email protected]
to answer your third question, why arent more people doing this. I cant speak for everyone. I havent done it because of time and money. I dont have the disposable income to pull it off, and I have job that I cant get away from for that much time at once. Before I hang up my helmet for good I want to run Bonneville and race Pikes Peak. After seeing the thread on Bill Collins, I have as much as 30 years to get it done.
I HOPE I have 30 years, but I don't KNOW that, so I'm gettin' while I still can...I still have one more thing on my list and it just happens to be Pikes Peak! We'll see about that one... If I lived in Texas like you, I'd be all over that paved course down there - maybe not as historical (yet) or unique as B-ville, but a lot easier to run on! I wish we had something like that here - although when Craig Breedlove was testing the last Spirit of America, he did so at a small dry lake here in Oregon. I've been asking around since then, but I don't know how he did it - if he got permission at all - since nobody's run on it since the '30s. But I digress...Back to the topic(s) - any more engine/suspension tuning advice from someone who's done it? Any other HAMBers going to World of Speed???
Jangleguy isn't alone here. Any and all info is appreciated. Loads of good stuff so far. Anyone know of a magical degree of rake for the salt? How low is too low?
Scotty--52/48 is about right--If you have time make some hefty weight bars and figure out a way to bolt them in the trunk. Remember--weight is not a bad thing. Dial in as much caster as you can, and as far as Engine pararmeters go--you can safely run 38 total degrees--and take some leaner jets--On a good day up there it is about 3,000 feet corrected altitude--but on a really hot, still day in the late afternoon the corrected altitude can go to 6,000. And it can still be wicked cold early in the morning...Of course if I was there, I`d have my Autographed Gosson Bros Sraitjacket errr T Shirt to keep me warm....
I am Tinbender remembered the castor. Personally I would shoot for 6 degrees positive, but that might be a bit much on the street with manual steering unless you have popeye arms. Another thing I would suggest is a good engine oil cooler. Long high gear runs put alot of heat in the oil. Make sure that everything has locknuts, loctite, cotterpins and safety wire. You would be absolutely amazed at what can fall off of a car after a couple of minutes of the engine at full song.
Hey!! Red head,I`m married! You can`t insert that thing there!! (heee hee) Scotty-- don`t forget to run your Tire pressure up a bit. Especially the Front. With the short wheelbase, It`s a good candidate for a spin.Spinning is O.K., but digging in and going on your head could ruin your whole day....
No scales yet. Breedlove tested at Alkali Lake, somewhere over by Klamath Falls, I think - looks tiny on the map, so don't know how fast they went there. Legend has it, guys used to run there in the '30s (according to my dad, who had a bad memory, so)...
My plan is to bolt 1"X3" steel straps to both sides of the rails (down low), as far back as possible, once I'm scaled and know where I need it to balance things out. Is that right? Caster is set and unchangeable on my Opel GT front end (welded in). Haven't measured it in years, but I'd guess about 7 degrees of rake (will check it this weekend). I know I'll need leaner jets, but I'd like a ballpark figure now, so I can buy an assortment within that ballpark (and don't get me started on todays ballparks!). Please excuse my ignorance, but what happens with timing at elevation? Doesn't more advance increase risk of detonation in higher elevations? I'm ascared of detonation...
PS - You guys rule! Thanks. Especially Kiwitinbender, who could easily rule an entire county. At least part of a county.....
I agree with the 52/48 front/rear balance. Cross scaling is important, the car needs to be square. Be sure you snub the front down as tight as possible, you need to maintain the same attitude in the timing lights as at the starting line. When adding ballast, between the axles is best especially in a short wheelbase car. Look me up when at the Wos. Good Luck, DW
Hey thanks Dan. What kind of car should I be looking for at WoS? Have you been doing this a while? Tell us a little about your experiences running there, okay?
Here are a few questions that I have, and I think they are right inline with Jangleguy's request. What are your feelings on a Pyrometer gauge for monitering exhaust gas tempratures? This would be a simple way for a salt newbie to keep tabs on their timing.... and what about a wide band A:F ratio gauge to go with it...knowing if you are rich or lean could save you a bunch of cash...not to mention tuning time. I will state up front that I know there are alot of variables in using both the EGT and the EGO sensors...but they are such valuable tuning tools for somebody that is running in a new environment, I felt obligated to bring them up. So for the pros...do you think these would be a good addition to a car that heading for the salt for the first time? thanks, reed
Jangle guy you'll want to lean your carb(s) a bit and drop your timing back a scosh but really if you dial in at 1200 feet you're not a ton of jets away anyway. Just get a standard track pack and you should be alright. If you're really worried about it take the old beasty up around Ontario in the high desert and dial it in up there. Its not that far from home and you should be real damned close when you get to the salt.
Lets hear comments on not running a suspension... Solid axles seem to be getting more popular. On advice of some pretty speedy guys, we're eliminating a suspension on our bellytank altogether. I know we're way over 3 questions now, but this is a very interesting discussion.
Dan's been at it awhile. He knows whats what. I wouldn't worry about detonation as long as you use race gas. If you've got a small motor run a lot of lead. Don't be too conservative on your tune, you can't go back next week to run the tune you should have the first time. I'd get rid of the fat rear tires also. Have fun.
Louis--Briz is building a new Pit Car that will crack you up...hopes to have it there--I will be there, probably in the A Bone if I don`t have to sell it first. Scotty--28 RPU is right as far as tune goes. See if there is someone at the meet running a similar combination and ask them for advice--ask them to read your plugs after a clean shut off pass--I`m sure you can do it but it never hurts to get another opinion.....
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