2021 Updates..
 

Updates and changes for the car for this year. Calvert split mono's replacing the stock leafsprings and caltracs. Replacing the rear shocks with Calvert single adjustables (temporary..had a great deal on them). Rear end is out ..axle tubes are welded..
The big change is a gear swap...for a few reasons..to lessen the load on the transmission, to see how the Continental reacts to the gear swap, swapping the UCC convertor back in during the season as well, looking to swap some sort of an overdrive into the car in a year or 2, dropping the 60 foot time down to sub 1.5's and also the car is driven more local not a lot of long highway miles.
So its a big change and definitely "geared" towards dragstrip performance and also I think this car has proved..you don't need a lot of gearing to have an all round performing car both on the strip and the street. I've also had some gentle nudging to see what would happen and document the results.

So no more 308 gears for now... 3.73's will be in this week.
Best et so far is 10.761 at 125.64 (car has seen 127mph in 2020) with a 1.5471 best 60ft
A few pics..the 4th picture is the factory spring perch that I just cleaned quick..

No doubt you will feel a difference. I'm going to change one of my cars from 3.23 to 3.73.

I'll be looking for the results. I'm thinking .5 to .6 second improvement in ET. Maybe a wee bit more. That is a big jump in ratio.

Good luck with it.

Im thinking 2 tenths gain..it may pick up more.

Nice! Very interested to see the gains. Thinking aboit replacing the factory mono leaf in mine with a set of Calvert split monos but havent pulled the trigger yet.

With the 3.73's you really won't need, (may not even want) that low gear set currently in the trans.

With it, it will sure be a head snapper, lol. It'll definitely tighten up the converter.

3.73's will however work real nice if you're planning an overdrive swap in the near future though. 4L80's with the 2.48 first gear works really well with 3.73's.

How do those Calvert split monos ride on the street? Maybe you haven’t driven it yet.

Its not assembled yet..waiting on parts.

Figured. Sorry.

The info I'm curious about, for the moment, is how the 3.73's do with your current trans, having its lower gear set in it (what ratio?) Might be some magic there...

How much gear ratio would you gain by going to the 4l80 and 3.73 setup?

Did you have any mods done to the UCC converter since you last used it?

Low gear set is a 2.75. UCC convertor has sat on the shelf since pulled. I'm going to run it this year to get data points on it for a refresh if needed.

Wow quite a change and I'm interested in your results as usual

following... will be interesting to see what the 3.73s do vs the 3.08, will definitely increase the RPM at the end of the track. good luck!

With the 2.75, and 3.73's out back, that'll be almost exactly like running 4.10's.

My 2.48/4.10 setup is slightly less effective. 10.16 vs your 10.25


Is the UCC converter looser than your current converter? I'm guessing that's the reason for the converter swap back to the UCC, since this gear change will tighten it up quite a bit.

Will be interesting and fun to play with this summer.

Yes that's part of the reason ,to use the whole rpm range in all gears..I'm only crossing at 5200 rpm with 10 to 12 percent convertor slip.

After looking at my data from last years runs I found the Continental is slipping about 10 to 12 percent at the stripe. So first thing is to see how the Continental reacts to the gear change. The next step will be to put the UCC in that was built for 342 gears but slipped too much for 308's..it should flash to 3800 to 4000..I want to see what the data is on it so I can send it back if needed for a restall.

Running 10s with it would suggest you have a "well built" one. Maybe different than apparent "near zero" slipping Continental..

It sure has many passes on it. It was also originally built for a 342 geared full weight 80 Trans Am with a 455 6x head engine. So its being worked pretty hard in drive with the current car with the 308's and 100 to 150 hp more than the original spec'd engine.
It has been a great convertor..has been behind 2 different cast head 455 engines, 2 different aluminum head 455's..used for 308 gears and 342 gears.

Any idea where your current engine makes peak tq and hp?

I would have to check with Dave Bisschop again but I would think hp peak is 6000 to 6200rpm..and peak torque in the 4200 to 4500 rpm range.

Wow that's a fair bit. I like how you're approaching it. Will be interesting to see how it affects both converters. Neat to see how quick the car really goes once all that is dialed in.

My stuff is never full dialed in lol.. I also have 2 carbs to try and spacers..my trusty 950HP Holley is still my et king..but my ProSystems carb has beat it for mph..just hasn't 60 footed as quick.

"It has been a great convertor..has been behind 2 different cast head 455 engines, 2 different aluminum head 455's..used for 308 gears and 342 gears."

I'm still using my original Continental 10" converter. Although it was originally spec's to be the same as the "Jim Hand" or "tight 10" version it flashes considerably higher than what most others report from those units. I've also used it behind three different engines and several different configurations of those engines, iron heads, aluminum heads, flat cams, roller cams, etc.

I will also add here that I tested quite a few versions of the Continental 10" unit including a "3800" stall version and one that we dubbed the "poor mans race converter" which flashed to nearly 4400rpm's. I also tested a few experimental units including one dual stator unit. Certainly no place to discuss my testing or results on your thread but I will say that the current 10" converter is by far the best of them, at least when it comes to being a good converter for both street and strip use with 3.42 rear gears.

I suspect that you will need to have the UCC converter tightened up some even with taller 3.73 gears. Just a guess on my part based on some of the testing I've done with 3.42 gears and more 10" converters than I can count. There is ALWAYS a trade off between flash stall, more torque multiplication and not coupling as hard once the car has "rolled out". When we make improvements in 60' with more slippage and whacking the tires harder we loose much of that improvement up on the top end of the track with less efficiency. Every combo will have a converter that works the best and many dedicated Class Racers go thru quite a few to find it. Not much different with what you are doing, if you take good notes, keep good records and don't mind changing them out and sending them back in with the results from each change.

As always looking forward to reading about how the changes work and thanks for sharing.......Cliff

Getting closer. Found some spare time yesterday and installed the upgraded rearend with new gears, split calvert monos,caltracs and calvert shocks. I'm pretty happy with the stance of the car it always sat a little high on the rear. Now it sits about 3/4 of an inch lower and I'm sure it may drop a little more once things settle.
Today I spent time removing the complete exhaust, I'm also installing new Dougs headers to replace my old Hookers and also reworking the exhaust for better ground clearance.

8.5" 10 bolt?

The same one I've used from the start with this car..had the tubes welded,fresh bearings and gear swap.and paint to look pretty.

Stock height Split-monos?

Yes stock height.

2021: replace dash Tach with 68 Rally Clock. Maybe replace 15 year old slicks. Spare 463 Engine build.

How close is the rear bar to the support cover? My 12 bolt i the Camaro looked awful close as the suspension moved through it's range so used a Pro Toruing F body that had longer arms to kick it back some.

Under full compression it is about an 1/4 of an inch away.

Skip,
Was that bar the same or a different diameter? The bar rate will change for the same diameter but with different arm lengths.

Stan

Well, I for one am disappointed. I loved what you were doing with the car with 3.08 gears and wanted to see if you could go even faster. Heck, I'd like to see how you would do with a 2.73... LOL! To me, a 3.08 is a real streetable gear, 3.73s, not so much. I mean they're fine for around-town but try driving 100 miles with them and you won't be too happy.

But, I totally get why you're doing what you're doing and I'll still follow your pursuits with great interest. I really appreciate your posting all your testing, mods, and results here for us to learn from.

Thanks for the kind words. It's all about testing and comparing results. The one thing that I wanted to improve was the 60ft time. There is no doubt over the last few years my threads have shown you don't really need much gear to go quick as long as you have good horsepower and a good convertor.
I could say I'm moving foward..at least I hope so? I will eventually go to some sort of an overdrive transmission to drop the rpms or maybe shift to a totally different engine drivetrain setup.
I just don't want to become stale in this hobby..for me it's the tuning and testing that I enjoy.
Once I get the car dialed in this year, I'm going to keep testing my 2 different carbs and spacers. I also may have another carb to test this year as well.

Different combos but we just went from 4.11 to 3.55 and didn't really see much. 60ft slowed a little maybe? Mph about the same. Overall worst case the car maybe slowed up .04. But it's WAY better on the highway.

We did something similar and didn't really gain anything. We went from 3.42's to 3.73's. I don't even remember gaining on the 60 ft times. Disappointed.

I predict an after market block on it way..!!

Although I've never heard you talk about traction issues. The slight lowering in the rear will shift the weight bias to the rear, slightly. This could also help with 60' times.

Yes that was the reasoning and also it sat up a little too high. I've fought traction issues at times on marginal tracks. Swapping to 3.73's I had to improve the suspension setup. So new split monos,caltracs and rear shocks. I'm also going to swap my 26 inch tall front tires to 27's this year..that will help as well.
As far as front shocks my CE 90/10's always have seemed to work well...I may have to tighten them up slightly. I'm starting initially with a set of Calvert singles in the rear. Eventually the car will have 2 ways at front and back..most likely Viking shocks.

I installed the Doug's Headers today to replace my old Hooker Super Comps. I had to clearance the driver's side control arm and slightly flatten a passenger side tube that was resting on the crossmember. I wasn't too pleased with that. I think the issue is the header mounting flange is too thick. If they made it thinner all the clearance issues would go away.
The middle bolt holes were easier to get at on the Doug's as well as a couple other holes compared to the Hookers.
But overall the Hookers actually fit and go on easier with any modifications..so a heads up to anyone making a choice.

round port or D port headers? & what size tubes for the hookers & dougs? i use the 2" O-port super comps on a 2nd gen that fit & install surprisingly well but hang a little to low for how low the car is.

what do the taller front tires benefit, just the stance or less rolling resistance that ive heard people say? i just changed my 26" fronts for a set of sportsman 28 that are closer to 27.5 to help get the nose up that sat too low.

I've had the same experiences. For some reason the Dougs always come recommended and I could never figure out why. I've had to modify every set I've ever tried, and it is a little disheartening after you spend the extra coin on the coating.
The Hooker Super Comps have always dropped right in for me. I've even experienced this on Chevrolets.

D port headers. When I bought the 26's M/T didn't sell a 27 inch S/R so I went with the shorter tire. The 27 will fill the fender better and level the car out a little more.

I've had as good luck with my Hookers as anything. Yes esp #5 bolt is a pain! With my RAIV 400 I needed smaller size 1 3/4 and the Hedman's would not even bolt up. Cut off 2 tubes and redid and easy bolt access!

Getting closer to a road test, fitted, tacked and welded the front exhaust section. Now I just need to tweak my tailpipes.and also clearance for the drivers side header again!https://uploads.tapatalk-cdn.com/202...b1156ea9cb.jpg

Sent from my BBF100-2 using Tapatalk

A taller tire will move the car back on the starting line and slow the RT. I tried running 26” front tires and had red light issues with an off idle launch no matter how deep I’d stage. 27” tires and running air pressure down to 25psi to make the tire “act” taller and RT’s are usually .01-.03 off the foot brake.

thanks for the info, good point about RTs. however i dont care much about RT's right now just doing test & tunes to work out bugs & see what the car will do... you can sit at the line for 30 seconds if you want & wont affect the ET's.

i have read/heard that a taller tire reduces rolling resistance though, not sure how much that will help et's or 60ft but it makes sense. i think taman meant the taller tire will help get the nose up more.

Something not mentioned, a taller tire also increases roll out. In other words the car moves forward more before it trips the beam and starts the timer. The car will run a slightly quicker ET with a taller front tire as a result, if you're careful how you stage the car (not too deep)

I finally had the car out for a test drive yesterday. Car feels lighter and more responsive. I notice the higher rpms down the highway, but the engine feels pretty happy at 2700/2800 rpm. The ProSystems carb is now able to quickly go to full throttle and has instant throttle response from a standstill. Thanks to a good local carb guy for advice and of course Tom Vaught as well.
I'm pretty happy with the stance of the car now as it sits almost level.

Have a few miles on them. feels the same. The car sits about one inch lower in the rear(it used to sit about one /one half inch above stock ride height. With the adjustable shocks I have them at 5 out of 9 for firmness. So I could actually soften the ride up if I wanted to.

Last two sets of dougs I had were on the disappointing side, both needed work, and the one a body set the driver collector was cocked to one side. I will probably go back to Hookers.


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