PY Online Forums - Bringing the Pontiac Hobby Together

PY Online Forums - Bringing the Pontiac Hobby Together (https://forums.maxperformanceinc.com/forums/index.php)
-   Pontiac - Street (https://forums.maxperformanceinc.com/forums/forumdisplay.php?f=418)
-   -   2021 Updates.. (https://forums.maxperformanceinc.com/forums/showthread.php?t=850236)

ta man 05-02-2021 03:16 PM

2021 Updates..
 
4 Attachment(s)
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..

napster 05-02-2021 03:27 PM

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.

ta man 05-02-2021 03:43 PM

Quote:

Originally Posted by napster (Post 6247104)
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.

Scott Stoneburg 05-02-2021 04:17 PM

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.

Formulajones 05-02-2021 07:16 PM

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.

promptcritical 05-02-2021 08:29 PM

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

ta man 05-02-2021 08:40 PM

Quote:

Originally Posted by promptcritical (Post 6247163)
How do those Calvert split monos ride on the street? Maybe you haven’t driven it yet.

Its not assembled yet..waiting on parts.

promptcritical 05-02-2021 09:35 PM

Quote:

Originally Posted by ta man (Post 6247169)
Its not assembled yet..waiting on parts.

Figured. Sorry.

77 TRASHCAN 05-02-2021 09:51 PM

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?

ta man 05-03-2021 01:00 AM

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.

OCMDGTO 05-03-2021 07:45 AM

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

78w72 05-03-2021 09:05 AM

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!

Formulajones 05-03-2021 10:42 AM

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.

ta man 05-03-2021 11:30 AM

Quote:

Originally Posted by 78w72 (Post 6247258)
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!

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.

ta man 05-03-2021 11:35 AM

Quote:

Originally Posted by Formulajones (Post 6247268)
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.

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.

pastry_chef 05-03-2021 11:47 AM

Quote:

Originally Posted by ta man (Post 6247280)
After looking at my data from last years runs I found the Continental is slipping about 10 to 12 percent at the stripe.

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

ta man 05-03-2021 12:12 PM

Quote:

Originally Posted by pastry_chef (Post 6247284)
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.

slowbird 05-03-2021 12:25 PM

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

ta man 05-03-2021 12:41 PM

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.

Formulajones 05-03-2021 02:07 PM

Quote:

Originally Posted by ta man (Post 6247280)
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.

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.


All times are GMT -4. The time now is 02:15 PM.