I dont know how to estimate this, or what information is needed. About what speed would a 3600 lb car going about 10.5 in the 1/4 mile finish? how fast if the car went into the high 9's? im trying to find out if the ratio i picked is too hig or too low. sorry if this is in the wrong section. thanks
According to those calculators my converter slippage is 38%, sounds awfully high to me, o No: what do you guys think. Wonder why they can't come up with a formula to figure torque using 60 foot times, I realize that getting % of tire slippage would be a problem. Just went back and refigured my MPH with a 30% converter and picked up nine miles per hour in the quarter, what's considered good for the slippage rate on a converter. My converter was built by Joe whats-is-name down the street, I beginning to wonder if it would run better with the stock converter back in it.
well is pretty close to what i actually run in my 64 Special 3800 lb 455 SPTH400 3.42 with a 26" tire My best time has been 12.86 at 106.78 MPH witch takes aprox 363 HP to the road aprox 450-480 at flywheel :TU: the rest of the numbers work out as well as in the speed and ET based on my weight and rpm coooooooooooool :laugh: :laugh: Ken
10.50's would be around 126 - 128 mph. There is some variation depending on how your car is set up (my car has never had much mph for the ET it runs). Vehicle weight has nothing to do with the relationship between ET and MPH; it only affects how much horsepower it takes to run that ET. A 9.85 pass is going to be around 134 - ish mph. K
i dont know what my slip is, if i called coan, they should know right? im going to make a thread to find some tires in The Hides for now. if i get a ratio of 3.5 and 28" tires, my top speed (without converter slip) is 142, meaning i have a max potential of about 9.7 but since that would drop down alot because of slip, i need to call coan.
10% or less is a good number to shoot for in a heavy buick with lots of torque.My guess is 125-126 with your ET goal,a little more gear will actually help the slippage as well as increase performance so it is a bit of a bonus. :beer
If 10% is a real good number for slippage then my 38% sucks pretty bad. I'd probably be better off with the stock converter in the car than with what I have. Course helping the slippage problem, while helping the MPH might not help the ET, could even make it worse. I really don't think my converter works very well.
buy a nice coan. so 10% and under is good. im still thinking of 3.50's and 28" tires, my only problem is finding thick enough tires for my rim... 16" rims suck for tire selection. i have only been able to find some baja tires, those would look weird on a muscle car. im shooting for a tread width of about 11.75".
I have two Coan convertors, an 8-inch 5600 stall and a 9-inch 5500 stall. I just ran my numbers through the calculator and came up with 9.5% on one and 10% on the other. I'd say Coan makes a good product. :TU:
Coan makes a great converter I know, but a little out of my price range. Does anyone know what the stock 455 converter stalls at?
Dave, not trying to tell you where to spend your money but, converter is one area that I learned you get what you pay for. I had a few different converters in the past from some other vendors (won't mention names) and the Coan by far is a superior product and worth every cent. Just my .02
I agree with you completely Jim, but you don't understand the situation. Been unemployed for 11 months and have a daughter getting married in a month, I can barely scrape enough money togeather to go race the car. In fact I haven't been to the strip this year.
I have spent the last couple of years working with converters both at the line and down track. If you find a company that will work with you on a couple of changes in he converter at no charge you can get them to really work good. The worst part is you need to take them in and out several times to get them on the money. If I have a converter that slips 10% It will be going back not even a second thought. I have two converters that I run with my GSE stuff neither of them slip worse than 6% and the best one is only 4.9%. I have also on the good converter gone to a ported stator which is better for a foot brake car they have told me. It transitions better in the middle they say I don't know but thats what they say. All I know is it was worth a solid tenth in the sixty over the other converter. if you work with a converter company and not throw a fit at them when it's not perfect right out of the box they will usually do what ever it takes to get it right. Converter technology has made leaps and bounds in the last couple of years. It used to be unheard of to have a converter stall at 5400 and have 4.9% slip at 6900 but they can do it if they try. I know that to be fact.
Dave, i have a nice stock 69 wildcat (430-TH400) converter sitting in my garage. Worked fine when i took it off, never made any measurements to check slip % though. so yeah, now the search is on for tires...
What kind of tires are you looking for?? white letter?? i know BFG and mickey thompson make 16" drag radials. but they're black wall.
What kind of tires are you looking for?? white letter?? i know BFG and mickey thompson make 16" drag radials. but they're black wall. also try www.tirerack.com
Dave are you sure you are entering the number correctly? 38% slip is like going down the track on ice. I have a trap rpm of 4800, tire height 26", rearend 3.31 trans is 1 to 1 and trap speed is 104.4. I should be going 112.17 so my slip is 7.48% PS: Call Bob and Geoff at Finish Line Motor Sports and have them match a convertor to your set up. You won't regret it. :TU:
wall doesnt matter to me, as long as theyre tires. ill check them out, but incase i cant find them, where did you see them?
