1972 Maverick Sprint - Phase 2

[Maverick]

Searched Mopars and Fords at LKQ junk yard in Durham today for 15X7, 5X4.5" wheels with 4-4.5" backspace. The ONLY ones I found were on a '93 4WD Explorer. They're gonna look dumb but they'll have to do for a few trips down the strip.

After I return the $25 junk tire and turn in the two freebee alloy wheels the cost will be $20/wheel.

Test fit was with the junk 235/78/15 tire which missed the leaf spring by 1/4".

[oldvettedad]

If I can find a scoop like that for you...and with your drag radials it oughta look something like this! If you can't beat that TB SS...you can certainly scare it

[Maverick]

Don't think so. But, here's a Sprint with a '69 Mach 1 scoop. I like it a lot but didnt want to copy.

[Maverick]

The drag radials are mounted and balanced. Put them on today and put a few miles on them to take the newness off.

2400 stall converter is in and it really improves things with the 347. I dropped the no-load idle to 1050 and it now idles quite smoothly at 900 in gear with the 100A alternator running the elect radiator fan. It's also nicer putting thru the neighborhood at 25-30 MPH. It previously was lugging but the 2400 stall lets the engine run a few hundred RPMs faster, and smoother.

Drivability is improved a lot.

The modulator got another 1/2 turn in to try get some later upshifts but they're still too early. Here again, the higher stall compensates and doesn't drop RPMs as much. The kick down cable is adjusted for full pull at WOT so nothing to be gained there.

Now, where is that TB SS?

[oldvettedad]

When is the next test and tune?

[Maverick]

Walt has some things to get squared away they we'll schedule it.

[Maverick]

We got back to the strip. Results are posted here viewtopic.php?f=2&t=1156

WXO has been table twidling and wondering about shift points. We ran an online shift point calculator to get an idea of optimum shift points based on transmission ratios and HP curves. This program does analysis for two theories: equal HP before and after shift and maximum area under the HP curve between before and after RPMs. The results for the Maverick are shown below. I won't be spinning it above 6K RPM, regardless of what the program recommends.

I had to extrapolate the HP curve to get into the RPM range that the program wanted.

**********************************************************************

Bowling's Optimum Shift Calculator
Input Parameters Are the Following:
Transmission Ratio One = 2.46 to 1
Transmission Ratio Two = 1.46 to 1
Transmission Ratio Three = 1.00 to 1
Horsepower = 100 at 2000 RPM
Horsepower = 160 at 3000 RPM
Horsepower = 190 at 3500 RPM
Horsepower = 250 at 4000 RPM
Horsepower = 265 at 4500 RPM
Horsepower = 270 at 5000 RPM
Horsepower = 260 at 5500 RPM
Horsepower = 255 at 6000 RPM
Horsepower = 225 at 6500 RPM
Computation Results:
Using the Criterion for Maintaining the Same Horsepower Before and After Shift:
Finding Best Shift Placement Points For Ratio 2.46 to 1.46:

Found optimum shift RPM at 6445, which achieves 231 horsepower and lowers the RPM To 3825 after shift
Finding Best Shift Placement Points For Ratio 1.46 to 1.00:

Found optimum shift RPM at 5950, which achieves 255 horsepower and lowers the RPM To 4075 after shift

Maximumizing the Area Under the Horsepower Curve:
Finding Best Shift Placement Points For Ratio 2.46 to 1.46:

Found optimum shift RPM at 6495, which achieves maximum area under horsepower curve, and lowers the RPM to 3855 after shift
Finding Best Shift Placement Points For Ratio 1.46 to 1.00:

Found optimum shift RPM at 6497, which achieves maximum area under horsepower curve, and lowers the RPM to 4450 after shift


--------------------------------------------------------------------------------

Bruce Bowling
bowling@cebaf.gov
Bowling Superior

[Basement Paul]

I didn't see any new results...

-BP

[Maverick]

I didn't see any new results...

-BP

Well, they're not very NEW anymore but the last results are in the linked thread posted Fri, Mar 16. I put a link in this thread because I said we were going back but didn't report results in this thread. Felt like a loose end.

[Maverick]

There are a few developments to report. After the stall TC was installed, the transmission was not downshifting -- starting in 3rd gear. Shifted fine manually. Called the transmission builder, Broader Performance, and talked to the techie. He says the governor is sticking. Says that's not uncommon for C4s.

The governor surrounds the tail shaft. The tail housing has to come off to get access. With the current exhaust system, the exhaust pipes have to come down to do just about anything to the transmission. Its about an hour of frustration getting the exhaust down and another hour of frustration getting them back in. Can't even get the trans mount crossmember out. Can't adjust the modulator with the cross member in place. So .... I'm gonna see if the exhaust pipes can be remade to allow the cross member and trans to come out with the pipes in place.

I was on the way to the exhaust shop when the transmission started working OK again so that trip was aborted. Since then its stuck in 3rd gear a couple of times so I am going back to the exhaust shop at some point so transmission tinkering will be easier.

When the exhaust system is reworked, I may fiddle with the modulator and governor myself or I may take it to a C4 genius to let him set it up for good shifts. If I understand it, the modulator controls up shifts on light throttle and the governor controls upshifts on WOT. Modulator also controls shift firmness under light and heavy throttle. Governor must control down shifts when stopping. Think it would be good to let the C4 guy get it all working correctly. Maybe I can learn a few things from him in the process. I'd love to be able to just nail it in "D" and have it shift where it should.

It looks like I have a deal on a pair of Cragars to replace the ugly Explorer wheels. A guy responded to my CR want ad and says he has a pair he'll sell for $40. Rims are still chrome but centers have been primed. That'll work for me. May do the black/white thing Fred suggested or may spray them with chrome paint. TBD. If the deal goes thru I'll get the drag radials mounted on the Cragars before our next trip to the strip.

[MostMint]

If you get to painting them, maybe consider a paint scheme to go with the Sprint paint scheme. White wheels, red pin stripe, blue on the letters of the center cap?

[Maverick]

The Mavericks originally didn't have a rear sway bar. One of the Phase 1 upgrades was to add an aftermarket rear sway bar and a beefier front sway bar. The car doesn't lean much on corners.

Problem was the mounts for the rear sway bar links weren't adequate. The links were mounted to the flimsy sub-frame with a 3/8" U-bolt threaded thru two holes in the bottom of the sub-frame. The U-bolt tears thru the sub-frame after a while. That had started on my Maverick.

Made some reinforcements from 2X2X1/8 channel iron today. Cut, reshaped, and welded the channel iron to fit the curve of the sub-frames. Welded 3/8" bolts, with the heads thinned down, to the channel. Tomorrow I'll re-install the rear sway bar with the new mounts with two bolts fastening each piece of channel to the sub-frames and Friday the local muffler shop will weld the channel to the sub-frames to really firm things up. I don't trust my up-side-down welding on the thin sub-frame. Too easy to burn holes when welding thin metal to thicker.

[wxo]

Hmmmm....how many pounds of steel do you think you've added to the Maverick?

[Maverick]

Hmmmm....how many pounds of steel do you think you've added to the Maverick?

Its still pretty light.

While the sway bar was being re-mounted, it also got repositioned so as to not encounter the differential housing and right shock on hard bumps. (I think.) Had to move it back a bit from where it LOOKED like it should mount.

[MostMint]

Gonna need some Lexan windows to offset the weight addition. Or a few lbs of boost.