Warning! Non Buick question. I have a friend (honest) who is building a full on (no roll cage) Pro Street 65 GTO. He isn't much of a poster on forums so I offered to ask you guys to see if you can help me (him) with some good links for setting up his rear end suspension. I'm not sure of the exact specs but it's a 4 link with coil overs (he will be running 18 inch Hoosier radials (which look very trick actually) and has all the usual (read confusing) mounting points. The guy who built it is a local respected chassis builder who set it up so it would work 'ok' and he would have to tune it from there according to what happenned when he first drove it. It's a BBC (hey, he sold me the Electra so he's not all bad) with multi stage Nitrous which should unleash a good amount of power. His ET calculator puts him into 9.5 second 1/4's if he can sort out his chassis and I really don't want him to loose control when he gives it the boot first time out. Where is the best source of info on the net for how to setup a Pro Street 4 link rear? Is there a book he can buy which you can recommend? Are there some general theories and 'best practices' Also, while I've got your attention. He wants to 'exactly' why he shouldn't block off the water bypass from his water pump to the intake manifold (BBC). If anyone can help maybe we can show him why joining a forum is such a good idea.
I've never used this before so I don't know how good it is. The only 4-link I've ever installed came with all the intersect points already figured out. From what I understand only a handfull of the hundreds of possible combinations are actually useable. http://www.etcracingprograms.com/images/software/4linkwiz/4link.htm
Thanks Alan. A bit pricey at AU$200 but it seems like a good piece of software. Anybody else have any suggestions? Is there a site that explains about how to achieve the correct instant center?
Sounds Risky...."No Rollcage,Radials,Possible 9sec ET's" I would definately sneak up on a combo like this,alot of easy/moderate passes to shake the car down. As long as the car goes straight,you can get aggressive with the launch,the car will probably spin the radials before it really makes any wrong moves on the starting line. Video tape would help. A good baseline on instant center is about 38". If the chassis guy set it up,he probably gave your buddy a good starting point.As long it goes straight,he can tune from there,as no two cars are the same. Will the local track let him run faster than 11.99 w/o a cage? Below 9.99 w/o a chassis cert.?
Chassis Book A great chassis book was written by Dave Morgan, called "Door Slammers: The Chassis Book". Cost is $30 and most Barnes and Nobles or even Jeg's carries it. Great reference guide for anyone who races. Tom Rix
Gary, you raise some excellent points. First off, let me say that he doesn't intend on racing the car at all. He's the sort of guy who doesn't feel the need to impress anyone or win anything so he isn't going to race the car or put it in any shows (althought with the amount of detail he put into it he could easily win several awards - I keep teling him but he just isn't interested) he builds his cars for himself and drives them mostly at night out of town...way, way outback. He won't be driving it during the day because if the local authoritoes caught this car on the car at all they would probably impound it. Rest assured though that he has attended to every detail and has left no mechanical component untouched and it is immaculate. He just wanted to build a fat tyred GTO and got carried away - it's been 10 years in the making. An example would be that he has managed to fit those massive Hoosiers under there and from the inside it looks stock all the way down to the rear seat which is still in the car and looks (and might even be) unmodified. I'm not sure that he gets on very well with the chassis guy any more and we live in a relatively small town and we don't have the option of going to another chassis guy because, well...there isn't one. He has totally dissasembled the car several times over several years. He wasn't happy with the (black) paint job 3 times and sanded it all off to start again. The same with the chroming of his bumpers; 3 times he got them to strip it back and start again. He's even managed to get refunds or reworks most of that time. He's got the patience of a... (choose your saying). This will be an awesome car. In fact I'm the one who calculated the ET for him as he wasn't interested in numbers at all. Not your average guy at all but an incredible fix it/restorer guy who will tackle any task with total precision and a 'there is only way - the right way' type of attitude. The only thing that he is concerened about it getting the chassis set up correctly and he is almost ready for it's maiden voyage into the back roads. Tom, thanks for the name of that book, we'll try to track one down. He's got all the measurements except vehicle weight at all four corners and won't be able to do that until he gets the car finished enought to roll out of the shed and down to a weigh station. He is aware of the need to calculate the center of gravity and the instant center but isn't quite sure how to go about it which is why he needs a good book or some software to calcualte it and he won't move the car one inch until he is satsified that the car won't lurch in some uncontrollable way. Never met anyone like him before. So, Gary are you saying that as long as everything is set up the same on both ends of the chassis (which it is) then it will launch straight? The only thing that chassis tuning will do is aid bite off the line? What effect does changing the instant center have and how do we calculate 38 inches?
