F41 Suspension performance
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Joined: Mar 2004
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From: Atlanta GA
F41 Suspension performance
Anybody know how many G's a factory F41 car would pull on the skidpad? I've got a '71 big block with an F41 + under it, and I'm trying to get a ballpark figure of what it'll do.
Le Mans Master
Joined: Dec 2003
Posts: 5,727
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From: Fremont CA
I have it on my 72LT-1 and without all that "iron" over my fron tires, my car has returned 1.3-1.4G's of latteral acceleration on my Valintyne Research G-Analyst (I would give the calibration errror of 0.2G's to this equipment.) The biggest difference was the Hoosier RS03 275/50/15 tires, they flat out STICK! I would say 0.8-0.9G's on sticky street tires (I also run 2.25 degrees negative camber in the front/2.00 degrees negative rear.)
Race Director
Joined: Apr 1999
Posts: 11,520
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From: CORVETTE 77 385 C.I. TEXAS
If you cut the front end weight to that of a SB, it can do well.
The LT-1 & 77 w/ FE-7 could handle very well. See 77 Facts on my website on sus. (FE-7).
Superfast80 website may have something on the LT-1 handling. http://www.corvettearchive.com/
The LT-1 & 77 w/ FE-7 could handle very well. See 77 Facts on my website on sus. (FE-7).
Superfast80 website may have something on the LT-1 handling. http://www.corvettearchive.com/
Last edited by Ganey; Nov 3, 2004 at 10:05 AM.
Safety Car
Joined: Oct 1999
Posts: 4,101
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From: NorCal
Tall Order
Wow, hard question! There are way to many variables, besides the two you mention, to come up with even a guess. Weight (both sprung and unsprung), tires, suspension setup, modifications, surface condition, etc.. all have a major impact. Seat of the pants feel says it's not going to be that great on my stock 'vert with F-41 because of the BB weight in front, but good tires would probably be the best thing I could do to improve it. My kid just picked up a G-tech pro, so I may play with that when I get a second and pass along the results. Good luck.
Hans
Hans
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From: Atlanta GA
To be more specific, I'm running 550 front coils, 360 rear composite, 1 1/4" front 7/8" rear sway bars, Bilsteins on all four corners, poly bushings, VBP strut rods, and I've got (but haven't installed yet) the VBP front spreader bar, poly diff mount, and crossmember reinforcing kit.
Eventually, I'll add aluminum heads/intake, water pump, etc., to lower my weight up front, and move to 17" wheels, but at the moment I'm running a fairly stock LS5 with iron heads and 15" rallye's with 225 front, 255 back.
I'm curious though as to how much of a difference the suspension upgrades have made: I can certainly feel a difference, but I'd like to know how competitive this setup is against other cars.
Eventually, I'll add aluminum heads/intake, water pump, etc., to lower my weight up front, and move to 17" wheels, but at the moment I'm running a fairly stock LS5 with iron heads and 15" rallye's with 225 front, 255 back.
I'm curious though as to how much of a difference the suspension upgrades have made: I can certainly feel a difference, but I'd like to know how competitive this setup is against other cars.
Drifting
Joined: Feb 2002
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From: Berlin
For a pure steady-state skidpad test on a smooth road, tires, ride height, alignment, and weight are much more important than the type of spring your car has. Out of those, the tires are definately the most important factor. Also, the design of tire is much more important than its size. Put on good modern tires, and you'll easily be in the ballpark of modern sports cars.
As a note, skidpad tests are a relatively small component of what gives a car a good handling feel, and F41 will make a significant difference there.
As a note, skidpad tests are a relatively small component of what gives a car a good handling feel, and F41 will make a significant difference there.
Instructor
Joined: Sep 2003
Posts: 173
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From: Apple Valley MN
I wish i knew what they did on a skidpad too. I also have the 550 lb front coil springs and 360 lb rear fiberglass leafspring. No shock upgrade. but have 17 inch rims with 275 width tires and man does this thing dart through traffic when you want it to
Instructor
Joined: Jul 2003
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From: eaton rapids mi
Originally Posted by DropTopBigBlock
Anybody know how many G's a factory F41 car would pull on the skidpad? I've got a '71 big block with an F41 + under it, and I'm trying to get a ballpark figure of what it'll do.
Don't know if this will answer your question but here's a link to a test that was done to 4 vettes in 1971. "According to Duntov, production cars can range all the way from 0.75 to 0.85G on the skid pad" as quoted from the article.
http://corvette.caranddriver.com/arc...p?articleid=54
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Le Mans Master
Joined: Dec 2003
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From: Fremont CA
Are you sure you have a 7/8" rear sway bar? The factory bar is 5/8" for a big block F-41. The front F-41 bar is 1 1/8" and while I have seen 1 1/4" diameter bars, I wouldn't run one, I would be concerned about ripping out the bar mounts with that big of a bar on my Vette. Your tires need help too if you only have a 225/15 front and 255/15 rear, the Vette has around a 50/50 weight distribution and you should run 255's all the way around especially with a heavy big block. I alternate between running a 7/16" rear bar and none depending on conditions that I am running my car while racing. The rear bar can "kill" response and feel for what the car is doing while at the races while it "feels good" on the street in most situations. The problem with many suspension modifications is you never approach the limit while driving on the street and have no idea what is really going on untill the day you "overcook" a corner and find the back end stepping out at the worst possible time. You need to go to a local autocross race and drive the car to it's limits and find out what the suspension does at the limit (I think the Vette Brakes 360LB rear spring is too stiff too!)
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From: Atlanta GA
It's a 7/8 rear bar: I wanted to bias the car to oversteer as opposed to understeer, which is why I went with the bigger bar.
Considering this tendency, do I still need to be running the same size tires all around? I was considering going to 255 front, 275 rear to accomodate that, and try to get maximum rear-wheel traction for acceleration as well.
Other than the strength of the mounting points, any reason I shouldn't run the 1 1/4 car up front?
Good advice on taking the car to the track; I live up in the mountains, and while I do drive fairly agressively, I'm not willing to push the car to its limits on a public road.
Considering this tendency, do I still need to be running the same size tires all around? I was considering going to 255 front, 275 rear to accomodate that, and try to get maximum rear-wheel traction for acceleration as well.
Other than the strength of the mounting points, any reason I shouldn't run the 1 1/4 car up front?
Good advice on taking the car to the track; I live up in the mountains, and while I do drive fairly agressively, I'm not willing to push the car to its limits on a public road.
