Hello,

I think I'm going to put some new tires on the 69 and I need a new rear spring and plan to go with the upgraded to the momospring.... and the while your at it bug has bit me... I know some upgraded Suspension would help the handling on this beast...

I debating how to go about changing the suspension and what all to change...

Mid America offers an entire kit for $1000http://www.mamotorworks.com/corvette-5-148-1349.html

Has anyone bought this kit? or have any others they know of that worked out really well!

Any opinions or experience offerings in this venture... would be great.

Later,

 

I have some doubts about a 3/4 rear bar matched to a 1 inch front
looks like a priscription for oversteer.

 

What set up do you have?

 

I don't have nothing right now. Front and rear spring rates look good
I ran a 9/16 rear big block factory bar combined with a inch up front.
Something like a 1 1/8 front bar with a 5/8 rear bar would be what I would try if I were doing it today. 3/4 rear with 1 inch up front just looks like an oversteer problem to me.

 

Have you considered the vette brakes & performance grand touring suspension if your wanting a good ride with improved handling it uses 460 front springs 330 lb fiber spring, bilsteen shocks 1.125 front bar .750 rear bar. It does not have the front a arm bushings included.


they have the same setup with stiffer front rear springs same sway bar combination if you want it.

 

I got this one from Zip:

http://www.zip-corvette.com/Zip/prod...84827DCEF8CD46

It has the same bars... all the kits seem to be that way lately.
I hope it's gonna be OK. Looks like you want to see a bigger front bar Mr. Mouse ??
-W

 

To be honest I would go through the VBP catalog use one of there
1 1/8 front bars with no bigger then there 5/8 bar in the back.
Someone would have to talk a long time to convince me of any
3/4 bar in the back even with a 1 1/8 up front. 3/4 bar in back with only 1 inch up front looks like a real invite to oversteer to me.

 

I don't dissagree (since I'm ignorant of such things) but since I already have the kit and limited funds, I'll try it and take it from there. My suspension is SO hosed I'm bound to be happy for a while - until I learn to re-adapt to it's new limits.

The only change I made to the kit as listed was an upgrade to Bilstien shocks for $110. Had I seen this earlier - I would have proposed a sway bar change.

-W

PS The VBP kit you posted above has 3/4 in the back and 1 1/8 up front. - you're OK with that?

 

You may well be OK.

Even a 1/8 change can change stiffness by a lot.

A front bar 1 1/4 is 2.44 times as stiff as 1 inch front bar.

 

I agree with everyone's comments about a 3/4 rear bar with a 1 in front being too small. I have basically one of these suspension kits on my car but did little changes progressively over 25 years to my 78 L-82 4 speed with the OEM F-41 suspension, not all at once with one of these kits.

Front:

1 1/8 stock OEM front bar with poly mount and end link bushings
New OEM front #550 coil springs about 1 in shorter than stock from Mid America
Bilstein Heavy duty front shocks with poly bushings on top (IMHO, the #550 springs are pretty stiff so I did not opt for the Bilstein Sports in front).
All new tie rods, idler arm, ball joints, etc
Poly upper and lower control arm bushings in stock control arms

Rear:

Originally ran 9/16 in OEM rear bar with poly mounting bushings with the poly mounted OEM stock 1 1/8 in front poly mounted sway bar, but the car still understeered slightly. I was looking to eliminate the understeer condition so switched to a rear 3/4 in bar with the OEM rear end link setup from Mid America. Stay away from aftermarket rear bars with horizontal end links like the front bar since this setup limits the movement of the rear trailing arms and contirbutes greatly to the oversteer issue that others have mentioned. The car is VERY neutral now with the 3/4 in rear bar with THE OEM REAR END LINKS (Mid America sells this 3/4 in rear bar with the OEM end link setup)!

360 monospring with poly mounting cushions
Competition strut rods with heim joint ends, not OEM strut rods with rubber or poly bushings (they will squeak) which eliminates much of the rear slop.
Bilstein Sport shocks (30% stiffer than the Bilstein HD's) in the rear only. I originally had Bilstein HD's in the rear as well which made the ride even better (very smooth) even with all the poly bushings, competition strut rods, with a 360 spring.

All these changes coupled with 255/45/17 ZR Kuhmo tires in front on SLP rims and 255/50/17 ZR Kuhmos in the rear have transformed the car into a C3 that actually rides real nice (not too stiff) and handles unbelieveably! At anything less than 10/10ths driving, the car is VERY neutral, no oversteer, but if you go beyond it's limits, it will begin to oversteer but it is manageable. C3's are set up from the factory to understeer severely especially the base suspension cars with no OEM rear bar. Even the F-41/Gymkhana suspenison cars will have a healthy dose of understeer built into the handling, probably since GM was concerned about liability issues since understeer is MUCh easier to control than oversteer to the average driver!

Hope that this helps!

 

You want a balanced setup. This is the factory high performance sus. for comparison.
Front 550 Rear 292 7 leaf
Front sway bar 1 1/8 " & adds Rear 7/16" bar.
HD shocks.

Note that the factory considered this too stiff for street w/o the rubber 73- body mount bushings. Some think it's too stiff even w/ them.
I really like it & have VB&P composite rear spring for less weight.

Some may find this factory high performance sus. handling interesting under 77 Facts on my website.

 

It helps but I'm a little past the point of no return with my kit. However I'm sure the OP is getting helped a lot - So that's a plus.

Since nothing is installed yet, I can at least do an exchange. Aside from the 1" front and 3/4 rear ; zip also has a 1 1/4 front available as well as a 7/8 rear.
From where I am now should I exchange the 1' front bar for the 1.25 front bar?

-W

 

I would at least go for the 1 1/8 in front bar and would either stick with the factory 9/16 in OEM rear bar with poly mounting bushings or Mid America's OEM type 3/4 in bar. As stated previously most people run into problems with the rear bar since they run aftermarket 5/8. 3/4, 7/8 rear bars with the front bar type end links which is a no no! If you are going to run a larger rear bar, I highly recommend a 3/4 in rear bar with the OEM type end links only!

On another note, be aware that factory steel spring rates as mentioned above are MUCH stiffer riding than composite springs. For example, a 292 steel spring rate mentioned above will be MUCH stiffer and ride much harsher than a 300 lb composite, no comparison. Another example, my F-41 steel rear spring was MUCH stiffer and harsher with OEM shocks than the VBP composite 360 with Bilstein HD shocks, again no comparison. With today's technology, you can make the car handle, steer, and ride MUCH better than the factory setup 35 years ago.

 

I have VB&P S/S suspension kit. 550lb coils in front but w/ a 330lb glass spring in rear. 1 1/8 front bar, 3/4 rear bar (the rear bar does NOT have the OEM type end links). Poly bushings, and bilst. gas shocks. I run a 235/60/15 front tires w/255/60/15 rears all on stock 8 inch wheels. The tires are nothing great, BFG radial T/As . The car sits about 1-1 1/2 lower in front w/550lb coils vs 460s. The kit comes w/a 360lb rear spring. I opted for a 330lb when ordering kit. Should have gone w/360. 330 squates too much under hard launch and has bottomed out over rougher (but not terrible) roads. I cant believe that the 360lb rear spring will effect ride that much. (I all ready have a pretty firm ride w/ 550lb coils) I was also leary about 3/4 rear bar being too much. So far not an issiue. Staggered tire size and the fact that I'm not running/racing at a track have a lot (maybe everything) to do w/it. Also running aluminum head small block w/ aluminum rad., aluminum waterpump, and headers. Car weighs in at 3,240 w/ out t-tops and w/ out my fat *** in it. Car has become much more responsive, and IMHO handles/holds the road very well for a 37 year old car. Not quite sure if I'd go w/550lb coils again. Unless your gonna run it at the track or attack every curve and on/off ramp all out, might not be worth the stiffer ride over 460 coils or even stock coils. Food for thought.

 

Since I'm already locked in... it's iether 1" or 1 1/4" up front.
I gather you'd opt for the larger one?

I hear you on the rear bar... but the money is spent and changes and upgrades will have to wait until everything else is done and run. That's already in the past for now.

-W

 

I bought a '75 with a '68 427 and the car had the original suspension (no sway bars on the rear!). I bought a complete autocross suspension kit - Bilsteins, HD sway bars, composit monoshock, 550# coil springs, etc. - from Ecklers a couple years ago. We decided to lower the car a couple inches since it would float real bad at 2X speed limit. We had to cut the springs down 1/2 turn, put on new body mounts. and reshimmed the body. Now it is tight as a drum and rides and corners like it is on rails (we also had to redo the exhaust system to get more clearance and install a Indy Pace car front spolier).

In fact it now corners so hard (well), that I ripped the power steering cylinder mount off the frame. Oh well, it was not too hard to fix. The car is handfull without power steering.

 

Definitely go for the 1 1/4in front bar if you plan on a bigger rear bar than the OEM one! Let us all know how you make out!

 

For most enthusiasts, when it comes to springs and bars I suggest sticking pretty close to the combinations typically found in available kits to keep you from getting into too much trouble. That said, to avoid guesswork, if you buy suspension bits a la carte, IMHO changing/adding bars is the last thing you should do after you see how is your understeer/oversteer balance. As has already been more or less brought up, it's vital to understand that any stiffening done to roll resistance on one end (springs or bars) will alter that balance unless countered by a corresponding change to the other.

And, I'm not a fan of giant anti-roll bars, as controlling roll is only one aspect of improved handling. While flatter cornering does feel better and less roll helps limit unwanted suspension geometry changes, since a larger bar increases lateral weight transfer at a given axle (and hence decreases available grip at the end of the car in question) it is possible to go too far and actually reduce your car's cornering capacity. This is why IMCO higher spring rates (as much as your bottom and the roads on which you drive will tolerate), which also take part in limiting roll as well as dive and squat (two things bars don't counter), is something worth considering while making these decisions. My $.02, free of charge.


TSW

 

Wow, I think I'm even more confused...

Bottom line

1. will this or one of these kits goning to increase handling and improve performance over my bone stock suspension?

VB&P Grand Touring Kit:
http://www.vbandp.com/detail.aspx?ID=479

Mid America Stage 4 Upgrade:
http://www.mamotorworks.com/corvette-5-148-1349.html

ZIP Suspension + Front end rebuild kit:
http://www.zip-corvette.com/Zip/prod...C13A28A896BD73

2. Is it enough of a gain that is worth the $1000.00

3. Which kit would you buy?

I basically drive this as a toy on the street with the ocasionaly thought of tacking it to the Drag Strip and maybe the road course...

Thanks for the feedback! Lots of passion in those answers!

 

Here is the kit I bought from VanSteel, it is a VB&P Street & Slalom. So far I really like it. Car feels much more in control and has a real performance feel. It also lowered suspension 1". In addition to the kit, I had T/As rebuilt, replaced all wheel bearings and suspension bushings with ploy bushings -- front and rear. I hignly recommend VanSteel, they helped me through the whole process and even followed up with me to make sure I got everything in okay.