AMC8

[JJacobs]

Good news/ bad news: drove it to the gas station and got a hellish case of death wobble. I figured that'd happen, I've got some weird stuff going on in the front end and it has 15 degrees of caster. So, that needs to be fixed before it can hit the highway for the drive home.

On the other hand, it seems to run really strong. It's been a year and a half since I drove it with the softer combo in the motor, so it's hard to say for sure- but I went about 2/3 throttle from 4K and it pulled harder than it ever has before. So that's good news. On the other hand, the centrifugal advance in the dizzy is locked out and it's at 36 degrees of timing. So hot starts are a little tricky.

MudDawg- a question about the TH400 for ya. I put the TCI Pro Super kit in it- included the Trans-Scat valve body mods, which were really only shimming the regulator, grinding on a shift valve and plugging an exhaust port. Right now I don't have the vacuum modulator hooked up and it needs about 3800 rpm to pull second gear, regardless of where I put the shift lever. The motor only makes about 6 inches of vacuum anyway, might be enough to make it shift at 3K instead? How do you go about tuning these old beasts? And no, I haven't hooked up the electric WOT downshift switch yet.

 

[JJacobs]

Last update since it's pretty much done. Rewelded the upper arm and went a little too far, has 3 degrees caster now, from 15. Still wobbles but not as often. I'm going to put another upper arm on it and use caster bushings to get back whatever I can, and add a steering damper. (I know this argument so please...)

I drove it 40 miles today and it does get hot. (85 degrees outside) Definitely needs hood vents or a cowl setup. It stayed about 220, and if you'd jump on it would hit 230 for a minute. This is on a stock 4.0 96 radiator with two electric fans. Hopefully I don't need to pony up for the $$ aluminum radiator.

Lastly, the trans has to come back out. Apparently I cut a direct clutch seal slightly on install, at least it's a relatively quick fix.
Otherwise, it's done. Loud, fast, and low. It's been a lot of work and $$.
Glad to be driving it again. arty:

 

[XJEEPER]

Just watched the clip.......love the sound of built V8 power! Nice to see you've kept your girlish figure too..........

 

[rebel68]

What kind of ignition are you running?

 

[JJacobs]

MSD billet distributor, 6A box.

Just got back from Bandimere, it ran 13.25 @ 104. Bandimere's at 5880 feet and the density altitude tonight calc'd to 8000 feet with all the humidity, so in sea level terms would be about 12.2@112. I wanted more of course but it only has 100 miles now and it's still getting dialed in- a/f ratio, ignition timing, shift points etc. It's within .3 of the old time when I had a 200 shot on it, so not bad I guess. I'll probably be putting the nitrous back on soon.

 

[MudDawg]

Man, that thing is stout....Bandimere is nosebleed city to a sealevel guy like me...I would need a supercharger to breathe LOL....Anyways...you can get an adjustable vacuum modulator to help dial in the trans...not only does it help control the shift points, it helps regulate apply pressure....a question on the build....you say you have plugged one port....did the mod also include the removal of the center seal in the low/reverse clutch piston??? also the governor weights can be fiddled with to play with the shift points....on my stuff I always ran a full manual valve body with the modulator removed and plugged....it was sort of harsh on the street and tended to chirp the tires pretty easy, but it eliminated guesswork on the set-up.

A tip on seal installation....take a small fine sharpening stone and knock the sharp edges off and follow up with crocus cloth....a feeler gage that has been fully deburred and smoothed will help with getting the seal lips in place. Think dull as a butter knife so it won't cut the seal....

 

[JJacobs]

I guess the trans kit probably should have came with a governor calibration kit. I might get one and play with it- who knows. I just need to back out the modulator adjustment a hair to firm it up on these idle-throttle shifts I always do running around town. When I jump on it hard I ratchet shift it through the gears, nice hard shifts.

hone: First dyno results are in- 362/359 rwhp/tq. Same torque, 100whp increase from the last build. With the too-small rockers that make my .521" cam .488". I need 1.6's and a solid roller setup and she'll be well over 400 to the ground. Oh, and the nitrous is going on next week.

 

[j99xj]

Very impressive numbers considering the atmospheric conditions.

Have you thought about going on "Pinks" and winning some redneck's hopped up muscle car?

I think you could win.

 

[JJacobs]

Thanks- yeah, the density altitude was about 8000 feet last Wednesday evening for the track times and about 7500 for the dyno pulls, but those are SAE standard corrected.

Pinks? Nah- there's a chance somebody might end up with a redneck's Comanche, too, and that wouldn't be good.

 

[rebel68]

You are running the holley commander 950 efi system, correct? I was just wondering if you compared it to retrotek's boss efi system? You seem quite knowledgable and I would like to hear your opinion. Thanks

 

[JJacobs]

Yes, I've got the C950. The Retrotek looks pretty cool, I see it's a brand new product so you might want to wait a while so those unavoidable bugs get worked out. The fuel table looks just like the C950 though with a lot more resolution. I like that it comes with a wideband, that'll save some dollars.

Two things though- they're trying too hard to look like a carburetor. For that money I'd much rather go multiport. TBI injectors normally are a cone design mounted well above the throttle plate and actually spray fuel in a pattern in a perimeter around the butterflies. The Retrotek appears to use a normal port fuel injector aimed right at the plate, which could very well cause fuel puddling and uneven cylinder to cylinder distribution. However, TBI's aren't known for even distribution anyway.

The other question- is it E85 compatible? It should be. How long E85 will be with is and whether or not it's false economy is a topic better left for another thread- but as of right this minute, it's an awesome performance fuel for dirt cheap. Whether it'll work with E85 comes down to the overhead available on the injectors and fuel pump and whether there's rubber parts in the throttle body unit and regulator. I guarantee their ECU will be fine with E85, what about the hard parts?

 

[NateST]

Great idea I'm sure that things going to be nice when its all tuned up. I saw in this magazine this guys rig was worth 80k i was wondering why.... he had a viper v-10 in his rubi.

 

[Beej]

Great idea I'm sure that things going to be nice when its all tuned up. I saw in this magazine this guys rig was worth 80k i was wondering why.... he had a viper v-10 in his rubi.

Maybe he has 80 grand in it, but I don't think that makes it worth 80 g's...