Stock mono's vs. Calvert Split mono's

[40Coupe]

I'd like to hear from those who have made this swap and what your results were.

[John_Heard]

I made the swap but far too many things were changed at the same time to do a A/B comparision. I think the big deal is that the front half of the split mono is thicker so they won't bend as bad as the OEM springs - that is an issue over time on a cal-trac type car. The other difference is the different spring rates available with the split mono's allowing you to lower the car if that is what your setup needs.

[40Coupe]

My setup isn't consistent on a marginal track and I'm looking at any suspension improvements I can make.

[Tom Rix]

I run the split mono Calverts on my Apollo (combo similar to yours, 3450#, 9 inch hoosier Radial slick, stock suspension, BB Buick) with great results. I was also inconsistent until I switched to the heaviest (stiffest) front half that they make. I used their back half that lowers car about 1-1 1/2 inches. It rides like a truck in the pits but now hooks on every pass. The only downside is if the track is bumpy it will unload the suspension so you must really fine tune with the rear shocks. I use DA front and rears.

Good Luck!

Tom

[MOOSE]

Yeah bumps in the track can be hazardous to your pocket book! Didn't have double adjustables on the rear and it came back to bite me. It will deffinately unload the suspension if you don't have a way to soften up the compression side of the shocks.



MOOSE

[40Coupe]

I run the split mono Calverts on my Apollo (combo similar to yours, 3450#, 9 inch hoosier Radial slick, stock suspension, BB Buick) with great results. I was also inconsistent until I switched to the heaviest (stiffest) front half that they make. I used their back half that lowers car about 1-1 1/2 inches. It rides like a truck in the pits but now hooks on every pass. The only downside is if the track is bumpy it will unload the suspension so you must really fine tune with the rear shocks. I use DA front and rears.

Good Luck!

Tom

How does your car 60 ft? Tell me about your combo.

What is the typical shock adjustment starting point on YOUR car front and rear??

[40Coupe]

Yeah bumps in the track can be hazardous to your pocket book! Didn't have double adjustables on the rear and it came back to bite me. It will deffinately unload the suspension if you don't have a way to soften up the compression side of the shocks.



MOOSE

Tell me more....what happened? I have AFCO DA's on all 4 corners and normally run the rear compression on full stiff.

[Tom Rix]

My combo is an IHRA Stock Eliminator Buick NA 455 Stage 2. Since the motor combo is restricted I have spent a lot of time sorting out the rest of the car. Front shocks are QA1 DA coilovers and rear shocks are DA Alston Varishocks (not coilovers). Calvert bars and spit mono's. I leave off footbrake on 2 step between 2400-2700 rpm. The 2 step keeps my lauches consistent and was worth .02 in 60 foot. Car is 51% front, 49% rear. I'm working on keeping the wheelstands to about 18-24" which should improve et. The past 2 weekends at testing it went 1.280 60' out off the trailer, followed by 4 consecutive 1.268 or 1.269 60's. Put 2 more degrees timing in it for the last run and went a 1.254 60'. MSD programable Digital 7 with TCD. 9' Hoosier CO6 with 22.5# air. Front shocks are set at full compression (stiff) and rebound is set at 18 clicks stiff out of 24.
With the stiff Calvert mono's I set the rear compression as Soft as they go and set the rebound from 1/2 to 3/4 stiff depending on track. If you have the compression stiff you will unload the rear tires every time you hit a bump in the track. I chased what I thought was a high speed ignition problem till I discovered this. The stiffer springs make you think differently about adjustments to the shock settings but they do work. I went from "dead hooking" about 50% of the time to 99% of the time. Even though it rides like a truck they work. Draw a white line on your front tires with shoe polish and see if that line moves while the car is in the air on wheelstand, if it doesn't you know you "dead hooked" and pulled front tires straight up.
Good luck with your combo and if you get a chance go to Dave Morgan's seminar, you won't be disappointed.

Tom

[John_Heard]

1.254 60'

Who says you can't make leaf springs 60' ? Right on Tom...

[40Coupe]

Tom,
Outstanding work with your Buick. I appreciate your help. I understand what you are saying about unloading on bumps.

I recently installed the Calvert split-mono 200 lb units. I have not gotten out to the track yet.

What does softening/stiffening up the rear compresson do to your 60 foots? Does it have much effect?

In addition, what effects have you seen by increasing/decreasing Cal trac preload? Seems mine has always wanted 1/2 turn or more.

My combo has AFCO DA's on all 4 corners and I've found on the rear that stiff compression and as much as full soft on rebound produces the quickest 60 foots. This was with the stock GM monos and on a perfect track. I realize it's going to take some time to relearn what it wants with the split monos which are a LOT stiffer.

[ytnova]

1.254 !!!! YIKES, that's a leaving b*tch! Congrats, I am sure you have a ton of time sorting that thing out.

[MOOSE]

40 Coupe,


I was at Mokan at a MAKO event. There is a transition bump from the new concrete to the asphalt. The transition bump was giving me problems during qualifying that caused me to lift or ride it out. I had single adjustable shocks on the back. If I took exstension away it would effect 60'. Not what I wanted in an 1/8 mile race. I left everything alone and hoped for the best. Well was on a a low 5.20 pass, hit the transition, upset the rear suspension, sent me toward the center line, corrected and into the guard rail i went. That's the short story.


MOOSE