Bracket Talk
Winter Project

This topic can be found at:
https://drr.infopop.cc/eve/forums/a/tpc/f/80760912/m/1817057196

October 01, 2019, 10:55 AM
ski_dwn_it
Winter Project
Ok for this winter I decided to FULLY half back the corvette. Right now its semi done with a 4 link / wishbone squeezed into the existing rear frame which limits my tire dia/width. That was fine with the SB434 but now with the BB555 I have to retard the timing to keep it consistent -which it is very - but I need a project. The best the car has gone is a 1.2460ft but I usually race it around 1.39 60ft for consistency. If I keep it turned up it will vary if the track starts going away.

With that said, help me pick the wheel/tire package most common or guide me on selection. I want to do it once and right. Looking back wish I would have just done this right from the getgo, but that was 12 year ago when I semi did it.

Want to go 32X14 or 32x16...figure at this point bigger is better. Opinions welcome. Going to get Weld Magnum or equiv. I don't want beadlock unless there is a definite reason why. Never ran them or screws to this point and haven't had an issue.

Give me your thoughts on backspacing and best slicks for this type car. Car is 3350 without me in it. 555CI motor on alcohol. Runs 5.7X@123MPH or 9.0s/teens@153MPH. That is leaving easy - with 19* retarded and ramping back in over 2 sec.

Thanks.



Configuration: 3350#, 582 C.I.,

60 - 1.24
1/8 - 5.53@ 126MPH
1/4 - 8.73@ 159MPH



3700#+210lb driver, FULL interior, through mufflers, 10.5 tire.
60'-1.333 (IN 4000ft DA! Joisy Math excluded; 1.25sec using JOISY MATH.) Wink
1/4 - 9.60@144MPH

October 01, 2019, 12:54 PM
Canted Valve
You will get some first hand advise. Believe I would also looks closely at the big chassis shops. Chris Alston and Quarter-Max comes to mind.


Illegitimi non carborundum
October 01, 2019, 01:26 PM
Mike Nitzsche
Tips I can give you. I do everything in round tube, so if you planning on using square stuff this won't really apply. 1) Make sure the tubs are as high as you can mount them. Yours will be in the back window I believe. 2)I put my frame rails narrower than the 4 link to provide clearance for the anti roll. 3) Use wheels with the least amount of back spacing to make removal easier. 4) Most backhalves require remounting drivetrain and redoing trans tunnel/firewall to achieve proper driveline angles, so be prepared. As far as beadlocks go, I have them on both my cars and truly feel they double tire life.
October 01, 2019, 01:42 PM
CURTIS REED
I was going to mention Mike's #3 but another benefit to the smaller backspacing is that shorter rear width is lighter.



____________________________
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2018 Div4 Goodguys Hammer award winner
October 01, 2019, 03:53 PM
rs72z
quote:
Originally posted by Mike Nitzsche:
Tips I can give you. I do everything in round tube, so if you planning on using square stuff this won't really apply. 1) Make sure the tubs are as high as you can mount them. Yours will be in the back window I believe. 2)I put my frame rails narrower than the 4 link to provide clearance for the anti roll. 3) Use wheels with the least amount of back spacing to make removal easier. 4) Most backhalves require remounting drivetrain and redoing trans tunnel/firewall to achieve proper driveline angles, so be prepared. As far as beadlocks go, I have them on both my cars and truly feel they double tire life.


Without derailing this thread, do you bend the tubing up and over the axle or do you go with a straight tube off the cross member to the shock cross member and then another straight back to the body?
October 01, 2019, 05:21 PM
ski_dwn_it
Thanks for the posts. I'm planning on and looking at the s&w 4 link frame setups. Likely round and definitely chromoly since the rest of everything in the car is moly. I can bend my own stuff but don't want to reinvent the wheel either.

My main concerns are really the wheels and tubs. Everything else I have a good grasp on. Problem is I need to order wheels and tires before everything else to mock it up. That is the guidance I'm looking for.

Definitely want the wheels to come off easily. My buddies is a pita and you have to deflate the tires, and wrestle with them for 10 minutes. Don't want that.

Going with fab
9 moly also.
October 02, 2019, 09:35 AM
Mike Nitzsche
quote:
Originally posted by rs72z:
quote:
Originally posted by Mike Nitzsche:
Tips I can give you. I do everything in round tube, so if you planning on using square stuff this won't really apply. 1) Make sure the tubs are as high as you can mount them. Yours will be in the back window I believe. 2)I put my frame rails narrower than the 4 link to provide clearance for the anti roll. 3) Use wheels with the least amount of back spacing to make removal easier. 4) Most backhalves require remounting drivetrain and redoing trans tunnel/firewall to achieve proper driveline angles, so be prepared. As far as beadlocks go, I have them on both my cars and truly feel they double tire life.


Without derailing this thread, do you bend the tubing up and over the axle or do you go with a straight tube off the cross member to the shock cross member and then another straight back to the body?


Straight. Tin usually fits better and there are theory's its stronger.
October 02, 2019, 09:53 AM
Mike Nitzsche
https://flic.kr/p/2hp9SjP
October 02, 2019, 10:30 AM
ski_dwn_it
Mike have more photos. Love looking at this stuff for ideas. Thanks
October 02, 2019, 11:01 AM
Mike Nitzsche
https://flic.kr/p/2hpbwpQ
October 02, 2019, 11:02 AM
Mike Nitzsche
https://flic.kr/p/2hp8LEL
October 02, 2019, 11:03 AM
Mike Nitzsche
https://flic.kr/p/2hpaEaf.
October 02, 2019, 01:19 PM
rs72z
quote:
Originally posted by Mike Nitzsche:
quote:
Originally posted by rs72z:
quote:
Originally posted by Mike Nitzsche:
Tips I can give you. I do everything in round tube, so if you planning on using square stuff this won't really apply. 1) Make sure the tubs are as high as you can mount them. Yours will be in the back window I believe. 2)I put my frame rails narrower than the 4 link to provide clearance for the anti roll. 3) Use wheels with the least amount of back spacing to make removal easier. 4) Most backhalves require remounting drivetrain and redoing trans tunnel/firewall to achieve proper driveline angles, so be prepared. As far as beadlocks go, I have them on both my cars and truly feel they double tire life.


Without derailing this thread, do you bend the tubing up and over the axle or do you go with a straight tube off the cross member to the shock cross member and then another straight back to the body?


Straight. Tin usually fits better and there are theory's its stronger.


Thanks Mike!!
February 12, 2020, 07:52 AM
ski_dwn_it
Update:










February 12, 2020, 11:09 AM
vetman
Sweet! Nicly triangulated. I like to keep tire clearance at 2" on center of tire for safety. Mine only has 3/4 at sidewall.Not a problem unless you exit track to fast after 1st round loss lol.


The difference between ignorance and stupidity. Ignorance is lack of knowledge. Stupidity is the inability to learn. Don't be stupid
February 12, 2020, 11:25 AM
vetman
Oh ya I see beadlocks!


The difference between ignorance and stupidity. Ignorance is lack of knowledge. Stupidity is the inability to learn. Don't be stupid
February 12, 2020, 10:07 PM
Hotrod Corvette
What are you doing for a trans mount?


Burt

I'm So Proud To Be An American And Not A Democrat...

February 13, 2020, 07:02 AM
SuperPro54
Great project!!!! keep the updates coming.
February 13, 2020, 07:27 AM
ski_dwn_it
quote:
Originally posted by Hotrod Corvette:
What are you doing for a trans mount?


I had a bolt in solid axle conversion I sold for these cars for years before this upgrade.
I used the Cbeam that was stock hold the trans. No loss of ground clearance and it Worked for last 12 years since the bolt in setup. Plan on keeping it the same. Works as a good driveshaft housing/guard also. All aluminum so its super light also for the size/length/protection it provides.
February 13, 2020, 07:44 AM
ski_dwn_it
I ended up running tubes ot the front frame. I made 2" tubes that extend down from the crossmember right below the 4 link brackets and then ran a tube the whole way to the front of the car to the front frame. So the lower bar on the 4 link is essentially pushing on the front frame member. In order to do this and keep it where I can put a seat back in the car and maintain the little ground clearance I have...I had to cut the floor in the area just infront of the crossmember below the seats, and install the bar where it raises up out of the floor and passes just under the brake peddle up inside the car. The bar essentially is between my feet at about 2" off the floor in order to hit the lower part of the front frame in one straight shot from the back to front. It is actually quite comfortable having the bar there to hold the heel of your gas pedal foot. This addition - while I did not want to really go that route intruding on the inside of the ****pit, really stiffened things up and gave me piece of mind that nothing was going to be flexing. Now the 4 links are basically tied to the front frame in a direct compression situation with that bar. I plan on putting two outrigging bars at midpoint to the frame 1/2 way up. these could be also used if extended inward for a crossmember. But for now they will be used to eliminate any midway flex the bar might want to do under load.

While I am not a professional builder - this project is very fun and I am happy with the results.

The best trick for measuring the tube to tube length I have come up with is using an extendable magnet pickup tool (like an antena)...extend it until it reaches tube to tube and that is the distance for the fishmount. yeah you can try using a tapemeasure but often times you can not see on the perfect plane to read it accurately. This above method works perfectly. Like a huge feelers gage. Pull it out, mark the tubes and cut your fishmouths.

I am using a hole saw and a bridgeport mill for coping the tubes. That makes it pretty nice also.