Trying to run NO subframe bushings, lowering the engine back down to compensate?

[BritishGreen68]

So here's what im doing lol.. Im trying to get my camaro as low as possible. I removed the subframe bushings and bolted it directly to the body to try and keep the sub from hanging down so far under the car, as well as lower the car a little more. Im running a T56 with sbc, and as we all know the T56 barely fits as it is. So, my plan is to notch the cross-member for the oil pan, and modify the frame/motor mount stands to lower the engine back down to where it normally is in relation to the body, so the tranny will clear the tunnel. Anyone else tried this? Tips tricks comments?? I don't want to cut up my tunnel...!
Issues Im seeing are headers, of which i will just run shorty's, steering column is flaming river so the u joint deal is already taken care of, and clutch linkage is easy.. should I bother doing all this?:faint:

[coolwelder62]

Sounds like your oil pan & trans now might hang below the lowest parts of the frame.Any hard driving and you might have a problem grinding some drive train parts on the pavment.Good luck.

[ProdigyCustoms]

Done it many times. Raise the transmission tunnel. Do not lower the oil pan lower then the crossmember

[elitecustombody]

Frank, how is the noise,rattles,vibration? I'm thinking of doing that on my 69 bird or should I just channel it?:unibrow:

[ProdigyCustoms]

No different then using solid bushings or welded in frame connectors.

I like to build all my stuff frame as rigid to the body as possible and let the suspension do the work

[Vegas69]

IMO, you need to cut the tunnel to get proper u joint working angles. When I say proper, I mean 1-2 degrees of working angle front and back. As low as we run these cars moving the engine down a little isn't going to gain the clearance needed in the trans tunnel to get a driveline angle that works well. With the high driveshaft speeds we are all after(5th gear at 100mph)smaller angles become critical for silky smooth operation. I wish I would've raised my tunnel. Otherwise, it's simply a compromise on u joint angles and vibrations of some kind will exist as your driveshaft speed increases. I'm still messing with mine to this day. Cutting my tunnel may still happen down the road.

[BritishGreen68]

IMO, you need to cut the tunnel to get proper u joint working angles. When I say proper, I mean 1-2 degrees of working angle front and back. As low as we run these cars moving the engine down a little isn't going to gain the clearance needed in the trans tunnel to get a driveline angle that works well. With the high driveshaft speeds we are all after(5th gear at 100mph)smaller angles become critical for silky smooth operation. I wish I would've raised my tunnel. Otherwise, it's simply a compromise on u joint angles and vibrations of some kind will exist as your driveshaft speed increases. I'm still messing with mine to this day. Cutting my tunnel may still happen down the road.
Ok, well sounds like I need to just raise the tunnel, that's good advise on the motor hanging lower the the crossmember as well. I actually had a diveshaft angle problem before all this, and always had a vibration on decel so i guess plan A is to get that squared away this time.. for some reason i always cringe when I cut up old sheetmetal, but its not like im ever going to put it back to 100% stock so what the heck..
Hey Frank, those Billet Specialties wheels I got through you are beautiful, I need a g link now. You got one laying around???:unibrow: :D

[Vegas69]

The problem is, when you lower these babies the driveshaft angle rises towards the rear of the car if you try to run equal and opposite angles with factory driveline angles(3-4degrees) the working angles reach 6.5-7 degrees or more. They can be equal and opposite but it will still cause a high speed vibration of some sort. I'd shoot for getting your driveshaft pointing down towards the rear of the car around 1 degree with a driveline and pinion angle of approx 2 degrees(equal but opposite. That will give you a working angle of only 1 degree and will run silky smooth until the car runs into the aerodynamic wall. (These are just estimates) Of course your rear suspension will effect if you need to put any preload in the pinion. With anything but leaf springs, I'd prefer smooth driving and less than ideal angle under WOT. Solid motor and body mounts will only compound any driveline angle issues and harmonic problems. I've done a little research and chasing my tail, can you tell. :unibrow:

[ProdigyCustoms]

Hey Frank, those Billet Specialties wheels I got through you are beautiful, I need a g link now. You got one laying around???:unibrow: :D

Ready when you are. Call me if you need any help.

[Vince@Meanstreets]

We do it on all of our builds to keep the geometry sane. As good as it feels you'll never notice the NVH.

Just a warning, it does take a bunch of work on some cars.

Radiator and shroud clearance. Steering shaft angle. As Frank mentioned, trans tunnel mods. Shifter location in console. Exhaust to floor clearance. Engine to hood clearance. Tire to wheel well clearance.

Oil pan goes up with the frame but watch your pan use and great points on driveline angle.

I like to use 5/8" dowels at the body/frame alignment holes and sleeves to keep thrframe in alignment after its gets squared.


Good luck with it, its a great mod.

Vince

[David Pozzi]

I'd like to add the T56 Magnum is a bit longer and makes any driveshaft angle problem worse. On the One Lap Camaro we had a u joint angles of 9 degrees front and rear, had a bad vibration at 57 mph. Reducing it to 8 deg is getting us by, but the trans needs to be raised to fix it totally. With the trans tail down, the pinion has to be nose up, this puts the driveshaft rising to the rear.
We have the ATS crossmember and it's the lowest thing on the car, lower than the exhaust.

[Vegas69]

Wow Dave, those are some serious angles. Mine was in the 7 range and I wasn't happy with it. I have some engine harmonics between 2650-2950 that compound it. I dropped my pinion angle down to .5 up to reduce the working angles and it improved it considerably. I ran out of threads on my adjusters but have new ones sitting here. My next plan is to lower the pinion to -.5 where I've basically taken the pinion out of the equation and that will lower the front working angle to 3.5-4 with a rear of approx .5. If I'm still not happy I'll lower the pinion angle to -2 and that will give me working angles of approx 2.5- 3 front and back. They wont' be equal and opposite but they will be small. From my research, when driveshaft speeds get to only 4000 rpm they don't recommend working angles over about 3 degrees. That's only approx 85mph with a .64 overdrive. Of course that's for silky smooth factory applications with miles and miles of reliability. When angles get so huge the driveshaft has to slow down and speed up more dramatically even with equal and opposites. It's one of those deals where I'm running solid body mounts, engine mounts, and QA1 rod ends to harness the power but want super smooth high speed drivability. That may eventually mean some tunnel mods to get those working angles minute. I'll try to remember to report back after my changes. Not sure when I'll get to it.

[GregWeld]

Back in the day -- they called what you're trying to do (getting the frame up into the car/or body down over the frame to hide it and reduce the ride height) - CHANNELING.... :rofl: :rofl: :cheers:

[XLexusTech]

can anyone post pics of the setup.. perhaps and under car shot.. and perhaps the tunnel mods required?

Also i have the ATS ls mounts which are reported to put the engine back and as low as possiable... would those help?:hail:

[Vegas69]

Mock it up and see for yourself. It's hard to speculate with so many different variables in this thread. Cutting the tunnel is the last resort but many times needed. How many times have you seen DSE slice up a tunnel. :cool:

[XLexusTech]

Mock it up and see for yourself. It's hard to speculate with so many different variables in this thread. Cutting the tunnel is the last resort but many times needed. How many times have you seen DSE slice up a tunnel. :cool:


well since my floor is sitting in a box in my garage I thought it might be something to look into with the floor still out..

[Vegas69]

How will you know how much you need? It needs mocked up.

[ProdigyCustoms]

I cannot find any pics, but there is no reason at all to not raise the tunnel a 1 1/2" or so to the tail of the transimission. Makes for more clearance when it is time to service the clutch also..

We just cut the top hat off the tunnel a 1" or so down the side, and make a wedge filler from the firewall to the back of the tranny.

[XLexusTech]

I cannot find any pics, but there is no reason at all to not raise the tunnel a 1 1/2" or so to the tail of the transimission. Makes for more clearance when it is time to service the clutch also..

We just cut the top hat off the tunnel a 1" or so down the side, and make a wedge filler from the firewall to the back of the tranny.


is this what were talking about?

http://www.pro-touring.com/forum/showthread.php?t=47480&highlight=raising+trans+tunnel

[ProdigyCustoms]

That is pretty elaborate. Sometimes lsee is more. You could cut it from the firewall back to the tailshaft, not even cut it off, rais the front and put a wedge in it.

Like I said, there is no real reason to limit this area.

[XLexusTech]

That is pretty elaborate. Sometimes lsee is more. You could cut it from the firewall back to the tailshaft, not even cut it off, rais the front and put a wedge in it.

Like I said, there is no real reason to limit this area.

Hi Frank... little bird'y told me that on project unfair your welding the floor higher up on the rockers. Since I have my floor out already is this something that can be done or is this something you doing on Unfair because of the AME frame?

[Blake Foster]

well since my floor is sitting in a box in my garage I thought it might be something to look into with the floor still out..

then just weld it in higher in the body????

the floor in the nova we are doing this exact thing to is MINT so the tunnel is coming out from FW to Rear seat

[XLexusTech]

then just weld it in higher in the body????

the floor in the nova we are doing this exact thing to is MINT so the tunnel is coming out from FW to Rear seat


that's what I was thinking and I was looking for some advice from those who have done this.

Specific questions like how do you make up the gaps in the area where the toe boards meet the floor?

I am at a bit of a disadvantage because I don't have the drive train yet so I am looking for some guidance as moc up is not an option for me right now

[dhutton]

that's what I was thinking and I was looking for some advice from those who have done this.

Specific questions like how do you make up the gaps in the area where the toe boards meet the floor?

I am at a bit of a disadvantage because I don't have the drive train yet so I am looking for some guidance as moc up is not an option for me right now

You just have to break down and subscribe to Super Chevy to see how they did it. That's what I did, the Unfair build threads are too much of a tease...

Don

[XLexusTech]

You just have to break down and subscribe to Super Chevy to see how they did it. That's what I did, the Unfair build threads are too much of a tease...

Don

I already get Super Chevy... what month has this mod outlined?

[dhutton]

I already get Super Chevy... what month has this mod outlined?

I think it is coming soon, maybe next month. At least that is my interpretation of the hints in the build thread.

Don