I think I've finally got the right converter in the Rocky, it's an 8" A-1 that I bought from MShred) that stalls around 5200 and hits right off the line....but now the wheelies are back.

When I had the 4k stall 9 1/2" and it wheel standed I just started adding some useful weight ( a remote filter and an oil cooler) combined with new OEM shocks and it would then hike the wheels only about 8" and carry them the first 10-12 feet. The new vert launches much harder but the tires dead hook and starts to lift the wheels much harder, with such a short wheelbase it doesn't give you much margin to work with as the angle it comes up is a bit more extreme.

I'm thinking I can extend the rebound snubbers to limit the free travel to give the nose a bit less momentum before it has to lift the unsprung weight of the suspension, does that sound like the best place to start? I'd rather try that before adding weight but I may have to do both.

Here's a short clip which was my first real test hit with the converter and new valvetrain ( springs, pro magnum rockers and MRL lifters)

http://youtu.be/OnZEy3Ij76c

Any advice would be appreciated, I could have easily flipped it over if I wound it out in low, I thought about hitting second ( would have if I had a RMVB instead of a FMVB) but even that can be a crap shoot with this kind of traction.

I thought about adding air pressure to the rear tires but they were already at 18psi, the M/T pro drag radials hook really well.

Thanks

I limited front end travel in my 'Cuda years ago by installing full size van bump stops. Knocked about an inch or so of travel out of it. Makes a big difference. Any sort of travel limiters would be a cheap fix. You only need a little more than an inch of rise. Maybe hang another 20 pounds on the nose somewhere, also.

You will probably never control it without wheelie bars. It is just too short and too high of a Cg to stay down, as noted by the video. Another thing to consider; will it be safe at speed?
You have the torque to lift the front when you got back in it, scary.

Wheelie bars are gonna be the answer with that short a wb and hi cg. Think I would be looking at down force at speed also. Insurance paid up?

Well I'm excited that I finally have the combo to put all the powe to the ground, with the tight converter it was very consistent low 11 car but it left really soft but it was very easy to drive. Power to weight should make it a legit low-mid 10 car but now that it's launching hard I've got to adjust and tune the suspension.

It's always been a lot of fun and now I know it'll be even more....it really goes very straight down the track. I know I can ride the bull if I can just get it out of the chute!

I really want to thank PBR (pittsbughracer) for the converter advice, the car really feels completely transformed with the 8" vert and the higher lift bullet cam compared to before it feels like it's got a full time 75 shot over the old combo.

I probably could have stayed content with easy low 11's but I knew the power from the motor was there and just not getting to the ground efficiently,..at least that doesn't seem to be the issue anymore, lol worst case it'll probably run in the 10's starting in second gear now.

I've heard of guys building 2speed ( glide ) turbo 400's, has this ever been done with our transmissions?

if it were me, i'd raise the pinion angle & hook second gear with my wheels in the air. i changed converters last season & it wanted to ride on the rear bumper. lifting the ladder bar up 1 hole fixed that & the shift into second allowed me to carry the wheelstand a lot further.

Griner was working on a trans-brake valve body for Flites that left in second gear. I saw one demonstrated,but not sure if it made it into production.

limit front end travel to 3 inches,and or add wheelie bars

I'm glad it worked out for you performance wise. I'm sure you will get the Rocky's chassis dialed in but it won't be a cake walk like it is on an A body car. These small blocks LOVE high stall convertors. It took some real testing but we finally ran some low 10.50's in Matts duster last year with the 727 and it s at 5400 stall. The 904 had a 5200 stall and a low gear set and was so much faster until we raised the stall again. Mines only about 5100 with my powerglide but I'm going to hit it with some more horsepower this year.

Thanks, PBR,

It's gonna be fun to sort out, friends are telling me to switch to a glide but I'd like to keep it all Mopar.

I wonder if anyone ever did any race development on the old Mopar Powerflight 2 speeds of the late 50's early 60's? If you could even find one today...I would imagine it shared some internals with the 904? I remember it didn't have provision for a parking brake, but I think it had a reputation as being very efficient and strong, I guess there was no aftermarket for it because the TF was just so good.

Adjustable front shocks can help. OEM shocks are just too loose on extension as well as compression. But wheelie bars would be the best safety device with something that wheelstands so easily. If weather conditions change for the better, that can catch you off guard. My car goes higher when it's cool & dry out early and late in the year.

I did see an early Max Wedge car a few weeks ago that wheelied easily and had a big, obvious weight bolted on up front.

I was wondering about an adjustable since the rocky takes a convention Bayonet top through bolt bottom like a Mopar ( it also has T bars btw)

Limiting the front travel with snubbers seems fairly easy, it was running 7.0's at right at 99 (1/8th mile) before the converter swap but this is a whole new animal now!

The issue with the wheel stand is with such a short wb it tends to come down pretty hard, limiting the free upward travel distance may help more than limiting the rate of rise from the shocks, but we'll see.

First what suspension on the rear and what shocks on both ends..
if you can loosen the extension on the rear shocks so the back lifts
more.. then I would build a adjustable limiter for the fronts.. I
also like to use a valve spring on the limiter so it doesnt slam to
a stop and up sets the chassis.. start with very little front movement
and work your way up.. if you have a 4-link in back you can dial most
of it out with adjustments on the bars(use a real short IC so it lifts
the back of the car and not the front)

Rear is stock leaf springs and Lakewood slapper bars with maybe about 1/4" of gap!!! It's just about pre-loaded to the front spring eye in neutral and slight rise at the 3000rpm stutter on the 2 step. The springs sit nearly flat with hardly any arch at all.

Rancho 9 ways are set on 9

Lenny (Melton) told me don't change a thing on the back, this thing will just about hook on Ice.

Gonna get some of those trimmable poly snubbers and start with about 2" rise and just make sure they come up evenly. I'll see where that goes

Isn't it fun having to much power. Lol

Soften the rear shock setting(extension) so the rear will
lift more.. it will be a bit harder for the front to lift
over the CG

It may take a few things, but start simple IMO.
On my car limiting the front end travel helps a lot. More rebound damping in the front shocks helps also. I replaced the stock A-body front end bumpers that were about 1.2" tall with ones about 2" tall. These were aftermarket (Lakewood?) bumpers for slapper bars that I cut down since they were way over 2" to start with. I use shims (large flat washers) between the bumper and the frame to fine adjust travel (.125" each for starters)

This so easy, dial back the power till it stops! Maybe a piece of wood under the accelerator pedal.

I wouldn't even bother with front shocks yet. Remove all the rebound travel you can in the front first. If this doesn't fix it front shocks aren't going to cure it either. Battery up front? It should be. Any weight you can either move forward or lower in the chassis? Lower is a big help.
Doug

Great advice guys...Thanks!

I guess having great power AND great traction is a nice problem to have...

Jim that's pretty much Exactly the approach I was going to take.

Mr P, if I soften the shock I'm worried about the softer compression (they're not double adjustable to my knowledge) lowering the CG more...Right now it just dips slightly, plants the tire and goes, I'm just thinking with the Rocky anything I can do to prevent raising the CG at all(LOL) could and should be avoided!

The back seems to be doing it's thing perfectly, if I can reduce the rate of rise in the front without unloading the contact patch that would be the best of both worlds.

Best move I made on my Duster was to put DA shocks on all 4 corners. Made a world of difference controlling the wheel stands.

Leaving in second will help, and won't hurt anything. Probably won't slow it down much.

First thing I would do is take that low gear set out

Lots of good suggestions posted. I limited my front to about 1.5 in of lift, adjustable shocks in the back. I'm running cal tracks with mono leaf spring, eight inch converter stalled at 54000 and a power glide. Weight ratio front to rear is 55% front. Foot brake car. It was wheel standing bad (3 to 4 ft) when I was launching it above at 3800 rpm. I dropped the launch rpm down to 3000 and reduced the wheel stand to about 18 to 24 inches with no change in ET.

Run a digital ignition box, take the timing out at the hit, and slew it back in as soon as you can.

All good suggestions,

I think I want to stay with the low gearset, I'd rather take gear out of the rearend than the trans.

I didn't mention that I went down from a 29.5" tire 295/65 to a 28" 275/60 M/T and both tires hook like mad but the new compound M/T's are just awesome.

I'm going to try limiting the front travel from about 5" down to around 2 1/2" with longer bump stops under the UCA's, the Rocky has heavy Lower control arms and spindles, by reducing the body rise momentum it will be more of a "dead lift" motion instead of a "Clean and Jerk" ....so the chassis will have to work harder to get them off the ground....if I time it just right I won't lose any hook in that first tire rotation, I'd rather try that than try to induce 1/2 a turn of wheelspin with more rear tire pressure.

I thought about a digital timing retard for the first .1-.2 as well but I'd rather try to leave with all the motor has to put to the ground...that will be an option if I can't find another way to keep from going too high.

Fill the front bumpa with cement lol.

And the engine block. LOL

Right now (since it was designed for off road) there is a 1.25" bumper attached to the bottom of the upper control arms that contacts a dedicated flat pad welded to the Frame. I think I'm going to drill and tap the flat pad to allow me to put an adjustable bumper in to contact the UCA. Right now the static rise is 5.5" before it makes contact, probably a little "generous" considering the 85.5" wheelbase, huh?

With the old 4K stall 9 1/2" converter it would just hike the wheels 6-8" and it was really easy to drive. With the 8" I'm feeling maybe another 50 hp worth of torque within 3 feet off the line, like I said it's like a nitrous shot by comparison.

Nothing constructive to add here but, I wouldn't mind ruining a rear bumper at least once just for a good pic Always wanted to start a thread called "Best way to increase wheelstands" but felt I'd take a severe Moparts style pummeling Carry on

Look how short the rear overhang is, Standing on the bumper would put me at about 83 degrees to the ground!

Standing her up is the easy part, setting her back down with a short wheelbase and a high stall/light switch converter may a bit trickier.

I think this thing would be a good wheel stander... Currently for sale.

http://huntsville.craigslist.org/cto/4996646212.html

The first pic shows how my brother's Gremlin left the line on every pass last year during Hot Rod Drag Week. 9.30's mostly, until the shootout, when he added a second plate system, and dropped to 9.0's. He eventually melted some pistons on an 8.95.

This year, new pistons lowered the compression, swapped the SRs for a set of -1s and backed the cam up four degrees. The 440 responded with a 9.08 on one system, but he was concerned about a 100 foot wheelie on that run.

The second pic was his first run trying to add the second plate.
He let off the nitrous early, and tried to drive through it, but when the rear tires left the pavement, and the engine hit the rev limiter, he lifted briefly. Gasoline hit the windshield, when he stabbed it again as the car started down, the engine simply bogged and was unresponsive. It's going to need a new rack, and the front rails straightened...but, he has the hero shot to show everyone!!

Caution, Streetwize, is the better part of Valor!!

Billy, that Gremlin is insane! Good advice and I'm a big fan of Clint Eastwood's "a man's got to know his limitations'

After some trial and error, I've made some bumpers that will limit the rise from 5.5" ( way too much for the short wheelbase) to about 2" before contact and 2 1/2" before it starts to lift the unsprung weight. That should still give me enough unsprung hit to plant the tires and also limit the trajectory of the wheel stand to something far more controllable, it should at least give me time to hit the next gear before the Rocky gets to the 'Event Horizon', lol.

I watched the video a hundred times trying to figure out where the balance point is, can't wait to try it out again, thanks for all the constructive advice!

Looks like a pretty good recipe for disaster , high center of gravity , short wheelbase , not sure where you are going with this but if you get there in one piece I will be amazed . I only offer words of caution rather than encouragement , having a safe race car should be the goal for you and the competitor beside you.

Go green,

Respect your opinion but as you can see in the video the car typically runs straight as a rail.

http://youtu.be/BB49eJu-YEU

It's been running consistent low 11's but the 60' has been slow high 1.6/low 1.7 so if I get the car off the line in a typical high 1.4/low 1.5 as it should with the new converter, the car should run mid high 10's which is all I really want out of it. It's got a 6 point cage and the chassis is rock solid and the steering is slow so it's really easy to keep straight. I feel more safe in this car than most of the cars I line up next to, it's very solid, nothing flimsy about it at all.