I've finally gone bigblock

[johnracer]

I've always been a small block guy in race cars, but had the chance to buy a BBC and couldn't pass it up. It's a ReherMorrison 522 that I've installed in my Vette roadster. Any thoughts on what thr car will weigh and what it run in th 1/4? With a SBC it weighed 2015lbs with me in it.
It's a 63 Vette roadster, 4.30 gear, PG with a 1.80 low gear, 33x16 Goodyears, and the 522 that dynoed at 839 hp at 7000rpm.
Fired it up for the first time tonight and it sure sounds & smells great!
Let me know what you think and, thanks....

[johnracer]

I failed to mention that I usually run at high altitude tracks like Denver or Salt Lake City. I'm planning on running in SG at the divisional in Tucson in a few weeks, but that'll be the lowest elevation this year...

[rsrsfishslayers]

I did not post this and I was not drunk tom????

[aaaaaaaaaaaaa]

they still make small blocks?.....LOL....

[signsbyesa]

hey fishslayer, that hotrod is smiling on the after picture :lol:

[zipper06]

I've always been a small block guy in race cars, but had the chance to buy a BBC and couldn't pass it up. It's a ReherMorrison 522 that I've installed in my Vette roadster. Any thoughts on what thr car will weigh and what it run in th 1/4? With a SBC it weighed 2015lbs with me in it.
It's a 63 Vette roadster, 4.30 gear, PG with a 1.80 low gear, 33x16 Goodyears, and the 522 that dynoed at 839 hp at 7000rpm.
Fired it up for the first time tonight and it sure sounds & smells great!
Let me know what you think and, thanks....

I think you have to weigh a min of 2350lbs, for super gas, so you may have to add weight.
Even though Tucson is factored for elevation, how you gonna slow it down to 9.90 plus factoring.
The car could run on sea level.

Your ET / MPH computed from your vehicle weight of 2350 pounds and HP of 839 is 8.21 seconds and MPH of 163.17 MPH.

Zip.

[johnracer]

Minimum weight for Supergas is 2100lbs, so I should be fine. I figure it'll weigh about 2200 with the big block. I have a co2 throttle stop to slow it down. I was just wondering what everyone thought it would run with the bbc. Thanks...

[johnracer]

Just got back from Tucson. The Vette weighs 2155 lbs full of fuel & me. I only made one full throttle pass then put it on the stop. Ran 8.44 @ 160.19. The corrected altitude was about 4100 ft.
Anybody out there run on a 4 tenths pro tree? I can't seem to get any better than a .030 light. I had the same issues with the small block and hoped the big block would take care of it but it didn't. It just rolls out of the beams with very little front end lift. Any suggestions?

[3dracing]

Turn the launch RPM up.



Steve

[johnracer]

I turned it up as far as I could. The convertor stalls at 6100 and I launched at 6000. I tried pumping up the front tires to 45 psi and the slicks to 6.5. I even changed the 4-link to a longer instant center. I'm pretty sure I needed to go lower with the IC, but I don't know for sure.

[topcat572]

You have a 6000 chip in a 6100 converter? :roll:

[hammertime]

I turned it up as far as I could. The convertor stalls at 6100 and I launched at 6000. I tried pumping up the front tires to 45 psi and the slicks to 6.5. I even changed the 4-link to a longer instant center. I'm pretty sure I needed to go lower with the IC, but I don't know for sure.


There is a few things I'd try here, try leaving off the convertor instead of the 6000 chip it should leave faster. In order to get my cars to be more aggressive down low I move the front bottom bar down 1 hole, but this will make it a little less planted down track. This works with my dragster should be same with your car. You should easily be able to leave on .400 tree with a probrake and that fast of a car.

[johnracer]

Thanks David. I was REALLY surprized that the 522 didn't yank the front straight up, but it didn't. It just goes straight forward. For some reason I got it in my head that a longer IC would help it pick up the front, but I pretty much ignored the IC height. This thing doesn't have any tendency to spin regardless of how I set the 4-link, so I'm gonna try a 50" IC at 4" high.
I really don't like leaving on the convertor which is why the 6000 chip. Normally, I 2-step it at 4800-5000 bracket racing, but at this point I'm pretty much open to any suggestions. Unfortunately, I can't test again until mid April.....gonna be a long month!
I've been a sbc guy forever, but I must say I'm hooked on big blocks already! It pulls like a big dog all the way through. Very cool....

[johnracer]

You have a 6000 chip in a 6100 converter? :roll:
I know, I know it doesn't make much sense, but sometimes I'm like that.
Actually, I just don't like leaving on the convertor...

[johnracer]

Well, finally got to test with the new IC location. 51.5" long and 4.3" above the ground. In Grand Junction CO at 6060' corrected altitude, ran a best of 8.64 @ 158mph with a 1.25 60'. Still drives straight forward/no front end lift. The track wasn't the greatest, but I'd think this little car should pull the front out of the beams no matter what.
On the full tree I had to pull the delay down to 1.080 to get in the .00's, so on a 4-tenth's tree, I'm still a duck. I'm sure it's a 4-link adjustment issue. Any other thoughts on getting the front to come up?

Johnny

[27keith]

Try tightening the struts and shocks. You can find alot of reaction time in those 2 items. 51" and 4 high sound pretty good to me for IC. You could always go shorter but that would getting pretty violent. Can you compress the springs on the struts any? this would "preload" the front some. Do you have a "pro" tree trans brake? .4 tree should be no problem with this car. Seen guys have problems with 4.10 gear but the 4.30 solved it.

[johnracer]

I do have a pro brake in it, but it's about 14 years old. If the car would pull the front up, I 'm sure the reaction times would come around. Maybe I'm just on the wrong track.
The way the chassis was set up Saturday, the front struts are set at full hard and have about 3/4" of travel at the current ride height. Yes I can compress the springs a little more and take out all of the travel.
The rear shocks are set at 2 clicks from full hard on both extension and compression.
I'm with you, it really shouldn't have any problem going red on a pro tree, but it won't even get close.....
I'm planning on testing in Denver this coming weekend and am considering getting one of the other SG drivers to try it. Maybe it's just me. I've always been a pretty quick leaver and still am on the practice tree....

[johnracer]

Any other thoughts or suggestions?

[triniemi]

1.080 delay and .000 reaction time on a full tree means a .020 on a .400 pro tree. I think it's perfect, red lights don't win rounds.

If you want to have red lights, try something that will lift the front tires off the lights instead of driving out of them. Maybe even ballast in the trunk would do the trick? What kind of weight distribution does the Vette have?

Jerry Bickel's chassisbook said that long and low IC reacts slowest, but keeps the tire planted longer time.

[sp2816]

It seems that since you had the slow reaction with both the small block and the big block that it could be in the transmission. Your car weighs 2160 and runs 8.64 and your 60ft was a 1.25. My car weighs 2650 and has only run a best of 8.90 and the 60ft was a 1.23, which I have been told is slow for my ET, but I leave at 4400 and only bracket race. I have a delay of 1.055 in my box and the transbrake is a full-tree brake not a pro-tree. It seems that reverse in your transmission is not releasing quickly enough and dragging, which would cause it to not 60ft and react like you want it to. I would think at your weight that it should have a 60ft of at least 1.19, and that would get you red.

Bill Mitchell

[johnracer]

.020's would be ok if I could do it in bright sunlight, but I'd like to get it to go red so I can adjust a little with the box.
The shorter IC definately helped some, but didn't lift the front. The best I could do with the longer IC in Tucson was .030, so I may move the top bar down one hole in the front and try again.
I haven't scaled the car, so I don't know about the weight distribution, but it's a purpose built SG car. I'd think it should be close. I do have some weight bars I can bolt in back.

Bill, I've considered the trans as a potential problem. When I installed the 1.80 gearset this winter, all the clutches looked new @ 250 runs, so I don't think it's dragging enough to affect 60' time. Maybe RT though. The valve body is old and probably has 2000 runs on it so the problem may be there.
With the sbc it 60'd in the high 1.30's with a 1.76 gearset and a 4.86 rear @ 2015lbs. I went to a 2.03 gearset and the 60's dropped to 1.29's. With a 180 shot, 1.21's. Believe it or not, my RT's didn't change.
The track was a little green this past weekend so it'll probably go 1.22 or so when it's stickier. I'm fine with that.
We're testing this weekend in Denver so I think I'll try the shorter IC and may a little ballast in the rear. If that doesn't do it, then I may have to nut up and buy a new brake.....sorry for the long reply and thanks guys!!