1994 convertable z28 drag suspension

At the moment I'm doing a LT4 motor swap. The lower end is built and has 190 AFR heads, Cant remember the cam specs but I know theyre Comp Cams, ported intake, BBK throtle body, shift kit, 2800 stall converter, 3.73 gears, and a NX nitrous kit 150 shot.
The motor is going into a 1994 convertable with stock suspension. The last guy that had it in is 1996 hardtop ran 12.5's on motor and mid 11's on the spray. My question is motor wise I belive it should see low 12's easy mabey high 11's with the right suspension so what suspension do you recomend I go with to get the most from this motor? Thanks

Well, I'm basically about to do the same thing, swap the stock stuff with some LE ported heads, ported LT4 intake, .597/.583 lift with 114 LSA 236/242 cam..should put out some good numbers...same combo on a friends 383 stoker netted 446 rwhp NA...but mines a stock 350 bottom end in a convertible '95 TA.

Anyway, I started with the suspension first, just put on a spohn torque arm as the stocker flexes and puts added stress on the tranny..the Spohn one relocates the torque arm to the tunnel brace.
The tunnel brace on the convertible is different than the coupes, its an "X" brace connecting the tunnel brace to the tranny brace.
I did this for two reason, get the stress off the tranny, and give me more room under the tail shaft for my dual exhaust (to be put on later) more clearance.
Now this setup does not use the X-bracing, but I modified the Spohn tunnel brace and made my own X-bracing thats on the convertibles...any extra bracing helps and I think it also helps in distributing the rearend noise a little too cause once the torque arm connects directly to the floorboard, you will hear more noise.
The torque arm makes a big difference already in reducing wheel hop to zero.
I have also already put on a modified pan hard brace and adj pan hard rod...this wasn't for a drag setup though, but was again for clearance of the true duals to get over the axle and the adj pan hard for the wider tires coming soon so I can ceneter the rearend if needed...so you may not need that stuff.

Next is SFC and boxed LCAs..in a few weeks.
I'll post up what I did with the X-bracing in a sec with some pics if it will let me.
Here's the post http://web.camaross.com/forums/showthread.php?t=395345

Well, I'm basically about to do the same thing, swap the stock stuff with some LE ported heads, ported LT4 intake, .597/.583 lift with 114 LSA 236/242 cam..should put out some good numbers...same combo on a friends 383 stoker netted 446 rwhp NA...but mines a stock 350 bottom end in a convertible '95 TA.

Anyway, I started with the suspension first, just put on a spohn torque arm as the stocker flexes and puts added stress on the tranny..the Spohn one relocates the torque arm to the tunnel brace.
The tunnel brace on the convertible is different than the coupes, its an "X" brace connecting the tunnel brace to the tranny brace.
I did this for two reason, get the stress off the tranny, and give me more room under the tail shaft for my dual exhaust (to be put on later) more clearance.
Now this setup does not use the X-bracing, but I modified the Spohn tunnel brace and made my own X-bracing thats on the convertibles...any extra bracing helps and I think it also helps in distributing the rearend noise a little too cause once the torque arm connects directly to the floorboard, you will hear more noise.
The torque arm makes a big difference already in reducing wheel hop to zero.
I have also already put on a modified pan hard brace and adj pan hard rod...this wasn't for a drag setup though, but was again for clearance of the true duals to get over the axle and the adj pan hard for the wider tires coming soon so I can ceneter the rearend if needed...so you may not need that stuff.

Next is SFC and boxed LCAs..in a few weeks.
I'll post up what I did with the X-bracing in a sec with some pics if it will let me.
Here's the post http://web.camaross.com/forums/showthread.php?t=395345

Do you plan on getting subframe connectors also?

Here's what I plan on getting to start with:

SFC001 boxed subframe connectors 169.95 TA001 adj. torque arm 329.95
TCA001 tubular lower control arms 119.95
CAB002 control arm relocation brackets 119.95
PHR002 adj. panhard rod 129.95
Edelbrock Strut Tower Brace

Stiill having a hard time finding a good shock, strut, springs setup.

Yep, I plan to install some BMR tubular subframe connectors in a few weeks...BMR was the only place I noticed that had convertible specific subframe connectors...I think Spohn's website specifically says their will not work on convertibles...and BMR has 2 different ones, one for coupes/t-ttop cars, and one for verts.
Also installing Spohns new boxed lower control arms at the same time.

Looks like you have everything covered on the rearend. I wasn't sure about front struts either, I know alot of folks claimed the KYB AGXs were no good for drag racing since they cannot be adj much more softer than stock, but the rear ones I have feel great, and I have KYB shocks of some sort or another on almost all of my vehicles and they definitely made a difference in ride so I went ahead and got the AGX's for the front but have not installed them. I wanted a stiffer ride anyway so the drag racing setup did not concern me and the car will be daily driven. Keeping the stock springs for now..

Rob,
I don't know which is better BMR or Kenny Brown Double Diamond subframe connectors, but just to let you know, KB does make them for convertibles too. I have them on both of mine. ;)
Ram

Rob,
I don't know which is better BMR or Kenny Brown Double Diamond subframe connectors, but just to let you know, KB does make them for convertibles too. I have them on both of mine. ;)
Ram You have a link? I looked on the website and I couldnt find them.

Rob,
I don't know which is better BMR or Kenny Brown Double Diamond subframe connectors, but just to let you know, KB does make them for convertibles too. I have them on both of mine. ;)
Ram
I just went on what I could find mentioned on the boards and on BMR and Spohns websites since they were the most popular. Not much info out there for the verts, I didn't have any preference when I started looking, and really still don't know after getting most of what I needed. Don't know which would be better, my guess is all of them do their job well if they are the weld on type. I have the BMRs, but haven't installed them yet, they are definitely some heavy mothers.

A buddy of mine had a 30th SS Convertible that ran 8.60 @ 160mph, with a 1.30 60-ft time. He had a set of MAC subframe connectors, that he installed when the car was almost brand new. He never found it necessary to use anything else (although the full cage probably helped stiffen the chassis quite a bit). The "double diamonds" are going to create problems with selection of a torque arm, and with the installation of an X- or H-pipe exhaust, if that's what you choose.

I would strongly recommend the Spohn parts.... the 30th SS mentioned above simply did not hook until Steve Spohn crawled under it. In the end, almost everything on the car was from Spohn Performance. The one thing Spohn does not make is an SFC for any of the LT1 4th Gens.... he has an LS1 4th Gen design, but the fuel line routing is different on the LT1's and the LS1 SFC will not clear them.

I found the convertibles really don't need too much in the way of anything different than the coupes. He even used my stock Formula springs in the back. At leat one part of my car has run "in the 8's" :)

Injuneer, what problems would the kbdd's present for torque arm and x-pipe selection? I'm seriously considering getting them. I have plans for duals in the future as well as a new crossmember and adjustable torque arm from bmr. Lastly, are the convertible sfc's available in a bolt-on format as opposed to weld-ons?

Does KB still exist? I thought they had disappeared? In any case, there are tubes that run from near the ends each subframe to the plates that bolt to the g-load brace pads at the DS tunnel. Those tubes can interfere with true duals, or with an X-pipe. I haven't personally done a KBDD install, but just knowing what they look like it would seem they could interfere with the exhaust.

I don't thing the KBDD's would interfere with some torque arms, but might interfere with others. The Spohn TA mount bolts to the same g-load brace pads, so you might have an issue with bolt length trying to bolt the TA mount and the KBDD's to the same pads. With a Madman TA, there would likely be an interference, since it needs a tube run across the bottom of the car from one SFC to the other. Not sure how the BMR would work, but I think that one requires some sort of front connection that could interfere.

Courtesy of Thunder Racing:

http://ww.thunderracing.com/catalog/summaries/s49_large.jpg

I was considering the BMR replacement brace and just attaching their adjustable torque arm to it, but it says it won't work on a convertible. Judging by the picture in your post, I can't see where there would be too much of a problem running duals with those sfc's. I'd just have to keep the pipes tight. The replacement crossmember looks like it would be the real problem. If I could get a double-hump style crossmember like the 5.0 mustang guys use that would be even better for my setup, but I'd still need a mounting provision for the adjustable torque arm because I'm not running the trak-pak.

As for kenny brown, their website is still up and working but it seems they're more geared towards '05 Mustangs. I just wanted a bolt-on sfc that seems more heavy-duty than the BMR sfc's. UMI has some three-pointers, but they don't fit a convertible. A shame, because the bolt-ons would have been the ticket. If I've missed something feel free to let me know.

I've got a 95 Vert, and here's the underside of it.. I used BMR sfc for a vert, and a Sphone TA that attaches to the tunnel brace. I modified the tunnel brace by welding on the extra "X" bracing like the original vert brace had. But with TA attaching to the brace, there's a ton more road noise inside the car.
http://hometown.aol.com/onebadwskier/images/95-full-underside.jpg

2QUIK6, the three-point sfc's attach to the stamped tunnel brace. If I could get a double-hump crossmember to replace it, I'd be set. I could probably negate the increase in road noise by using some neoprene or rubber as a gasket of sorts between the brace and the floorpan. If I could also mount the adjustable torque arm to the crossmember with a polyurethane bushing like BMR uses, hopefully the road noise wouldn't be so bad. As a last resort, I could use sound deadening mat under the carpet. If I'm way off base, let me know.

2QUIK6, the three-point sfc's attach to the stamped tunnel brace. If I could get a double-hump crossmember to replace it, I'd be set. I could probably negate the increase in road noise by using some neoprene or rubber as a gasket of sorts between the brace and the floorpan. If I could also mount the adjustable torque arm to the crossmember with a polyurethane bushing like BMR uses, hopefully the road noise wouldn't be so bad. As a last resort, I could use sound deadening mat under the carpet. If I'm way off base, let me know.
I would think the 3-pt sfc would just bolt to the same holes the tunnel brace bolts to no matter what tunnel brace you had as long as the holes match up, just need longer bolts, the tunnel brace would be on the bottom either way with the sfc sandwiched between it and the floor pan.

I had the poly bushing in the TA and also tried putting a piece of tire rubber between the tunnel brace and the floor pan and it didn't help much. Seems like all of the road noise and drive train noise just permiated thru. I ended up removing the Sphone Adj TA and the tunnel brace it connected to. Put the stocker TA back on and fabricated a custom tunnel and X-brace to accomodate true duals. If I ever snap the tailshaft, then I'll be forced to deal with the noise, but this is also my wife's daily driver and she didn't like the noise either so she started putting the miles on the 30th anniv..another reason I went back to the stocker :)

Havent seen this thread in a while. That motor was a scam lol. Anyways I went with BMR sfc's, relocation brackets, adj panhard rod, adj LCA's, C/E rear shocks w/ stock rear springs, Global West torque arm (not installed) and qa1's front single adjustables and springs 300# in the mail and bfg 315/35/17 drag radials in the rear. Shooting for 1.5's or better with my 383. As for the double diamonds I dont see the point of them when they can get in the way more than they help.