Landracing Forum
Bonneville Salt Flats Discussion => Build Diaries => Topic started by: robfrey on July 21, 2012, 06:12:40 AM
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(http://i749.photobucket.com/albums/xx135/BR_LSR/C4%20Corvette/d118e0a8.jpg)
I guess it is time to start a build thread about this car even though it it pretty much done as I feel no car is ever really done in this sport.
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Rob,
Did I understand that this car will be at SpeedWeek this year?
If so, I will look forward to seeing the fine craftsmanship.
Regards,
Dave Gray
Carlisle, Pa.
# 3611
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Nive looking 'Vette.
Regards, Neil Tucson, AZ
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Yes, Lord willing, we will be at Bonneville.
The purpose of starting this thread is threefold for us.
1) share our adventure (hopefully forum members will come visit our pit at the salt so we can put names with faces)
2) maybe other forum members can help us be SCTA compliant.
3) safety- anything that develops because of our discussion here that helps prevent a high speed blow over and subsequent destruction of the car would be a good thing.
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Btw, thanks Neil!
Looking at the rule book, I do not see that I can use a spoiler with side plates in Modified Sports class. Is this correct?
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2012 rulebook allows spoilers per 4.CC.8 (page 45-46) in Modified Sports (5.D.4, page 71). And with that engine, you're gonna need one! I'd go Design One. vic
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2012 rulebook allows spoilers per 4.CC.8 (page 45-46) in Modified Sports (5.D.4, page 71). And with that engine, you're gonna need one! I'd go Design One. vic
Ditto... and weight on rear wheels. Spoiler will add downforce but hard to figure with out knowing pressure difference above
and below spoiler. A2 wind tunnel?
Hope to meet you :cheers:
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Is it legal to have the roof rails that are on the back window not be in line with with the roof rails that are on the roof?
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I'm asking the above question because I was hoping to simply weld uprights (3/4" tall) to the existing window retainers that are not in line with the roof rails when the car was originally built.
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Is it legal to have the roof rails that are on the back window not be in line with with the roof rails that are on the roof?
Call Jim Miller 818-846-5139 modified sports committee
JL222
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Went 252mph this afternoon on 247 record. Something is up with boost controller though and it only made 7 psi of boost. We see of we can back it up tomorrow.
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Never figured out what was up with the boost controller. Still had enough hp to run 250 on the back up run.
Thanks to all the officials, big Tim the tech inspector, Lee Kennedy and the rest of the SCTA-BNI crew. These events do not put themselves on.
Being close to the crew that puts on the "Flashlight Drags", I understand this is a monumental task.
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Congrats on record with low boost :cheers: Will haul ass with controller figured out.
We looked for you before we left, but you must have been in inpound.
JL222
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Woody just sent me some cool pics!
(http://i749.photobucket.com/albums/xx135/BR_LSR/C4%20Corvette/P1070628.jpg)
(http://i749.photobucket.com/albums/xx135/BR_LSR/C4%20Corvette/P1070619.jpg)
(http://i749.photobucket.com/albums/xx135/BR_LSR/C4%20Corvette/P1070618.jpg)
(http://i749.photobucket.com/albums/xx135/BR_LSR/C4%20Corvette/P1070617.jpg)
BTW, car is for sale. Check the Classified section :cry: It was fun while it lasted.
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"Call Jim Miller 818-846-5139 modified sports committee"
Don't call Jim. Lee Kennedy is now your man.
DW
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Rob, there are lots of race cars for sale on this site year around and quite frankly I grew a little weary of your resurfacing advertisment every few weeks, even with its continuous drop in price.
Not being one who enjoys eating crow (or fois gras or what ever that sh*t is called), I want to personally congratulate you and the presumably broke owner for having the balls to bring a "unfinished" and for sale race car to the Salt and kicking its ass.
If the car is ever to sell, this ought to do the trick, and if not, get rid of the Corvette Body and sell the rest for even more money.
At the risk of being tarred and feathered, very few Land Speed Racers give a Rat's As* about Corvettes, but "records,", well thats a whole different story...........
Congrats from a "wannabee"......................... Bob
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Well..... A FEW of us give a rat's As* about Corvettes................
Ed
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Ed, if you recall, I talked to you back in 08 about running a Vette as we had started the build about that time. Keith Turk had introduced us. Thank you for the great advise.
Bob, owners are definitely not broke and the car was not for sale when we were at Bonneville. The owners (two lifelong friends) bought the car about 8 weeks before Speedweek. I don't know how they avoided catching salt fever but you know, this kind of racing is not for everybody. If the car does not sell, we will go to plan "B" and go back and try to break a few more records next year at Speedweek.
Btw, I've eaten more than my fair share of Crow. Of course my share is naturally large because I can't keep my mouth shut. LOL!
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Well..... A FEW of us give a rat's As* about Corvettes................
Ed
We all have our favorites.
By the way, when did we start picking on others choices in Land Speed racers?
Dave
# 3611
56 Corvette
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We did all decided though that the transmission in this car was a home run once we worked through the bugs. We had twisted off the input shaft at the Ohio Mile on the cars first run. Since that time we have gone to a M300 input and intermediate shaft and also lifted off the throttle to shift. This kept the shock loads down on the rest of the drivetrain and kept us from breaking the tires loose during the shifts. Because the transmission has over running first couple of gears, shifts were very smooth. We are also using a custom valve body made by TMC which has a lot of safety features like reverse lockout, steering wheel shifting ( it was nice to be able to keep both hands on the wheel), and if the engine would ever lock-up, trans automatically (within about .2 seconds ) goes into neutral to keep from locking up the wheels.
Oh yeah, Coan had also built us a custom converter that has 3 clutch disk and a higher stall that acts like another gear split.
The shift pattern that we used was - 1st, second, third (1:1), fourth was actually third with the converter lock-up, then fifth was overdrive with the converter locked up. Worked like a champ!
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Rob, there are lots of race cars for sale on this site year around and quite frankly I grew a little weary of your resurfacing advertisment every few weeks, even with its continuous drop in price.
Not being one who enjoys eating crow (or fois gras or what ever that sh*t is called), I want to personally congratulate you and the presumably broke owner for having the balls to bring a "unfinished" and for sale race car to the Salt and kicking its Acura.
If the car is ever to sell, this ought to do the trick, and if not, get rid of the Corvette Body and sell the rest for even more money.
At the risk of being tarred and feathered, very few Land Speed Racers give a Rat's As* about Corvettes, but "records,", well thats a whole different story...........
Congrats from a "wannabee"......................... Bob
The tar is being heated, the feathers are in the bag. The party will start soon. :cheers:
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Glen,
Please make sure the tar and feathers are at least SFI 3.2A/15.
I wouldn't want this to interfere with his record persuit.
Besides that, knowing Bob he would probably enjoy it. :-D
Don
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It'a OK Glen, if Bob doesn't get his one run he gets crochetier each off season.
Bob, lighten up. Perusing your recent posts would make Kaptain Kangaroo wanna stick his head in the oven and turn on the gas! :-D :-o :evil:
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Rob, it was great seeing you on the salt, and even better seeing you enjoy success! :cheers:
I'm moving the rig closer to you this week(Marionville), so hopefully we can catch up again!
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Rob, it was great seeing you on the salt, and even better seeing you enjoy success! :cheers:
I'm moving the rig closer to you this week(Marionville), so hopefully we can catch up again!
It was great to see you and your hot rod on the salt also. I will be in touch sometime this week. Marionvilel is close.
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This is what the horsepower curve looks like that we ran at Speedweek to set the record.
We only spun the engine 5800rpm in high gear (overdrive). At this 7.5 lb of boost, that is just about all she wanted to spin as power met wind resistance. We should be able to make 30 psi of boost but I had designed the package to run at 25 psi and it should live pretty long at that power level. If nobody buys it, I would like to add piston squirters and valves spring oilers for next year. I'm trying to just keep thinking about longevity, longevity, longevity. I've been studying what the offshore boat guys have been doing.
(http://i749.photobucket.com/albums/xx135/BR_LSR/C4%20Corvette/75lbsofboosthpcurve.gif)
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As it stands right now, looks like we will be running the car again in the Modified Sports classes next year. Blue has some ideas to fix the aero problems associated with the stock body.
Taking this car to Bonneville also solves some logistics problems associated with the NACA 66 Special streamliner as we planned on taking two trucks w trailers anyway.
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Getting back to work on the Vette a bit.
Here are some weight numbers we were running.
4620. lbs total vehicle weight.
55.4% of that weight on the rear wheels.
This could explain the handling issues.
Also, the 61 gallon ice water tank was not baffled. The sloshing added to the driving challenge.
Our recommendation to the car owners is to let us build a baffled 25 gallon icewater tank where the turbos are now and move the turbos to the rear.
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Finally got started mocking up on the spoiler as we make the move to modified sports.
(http://i749.photobucket.com/albums/xx135/BR_LSR/C4%20Corvette/null_zps3879f652.jpg)
(http://i749.photobucket.com/albums/xx135/BR_LSR/C4%20Corvette/null_zps91bf0626.jpg)
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In A/BGMS?
Regards, Neil Tucson, AZ
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Yes sir.
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Here a quick video we made on the Dyno.
http://youtu.be/iv8NqJN4OtU
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Rob,
Pretty awesome!!! I like the new "tail fins" also maybe they will help keep it straight as you go past 260!!!
Rex
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Here a quick video we made on the Dyno.
http://youtu.be/iv8NqJN4OtU
Rob...sounds like gangbusters and way more than 1000 hp, must have had a bunch of tire slip.
Tires don't look like LSR.
Was that black smoke at end of video, from tires or engine?
Dyno for the 222 Camaro had 2 rollers which helped with tire slip but we still let a bunch of air out of tires
chinched it down with come-alongs, chains and straps and blew the tires back up to 50lbs.
We also have 3000+ lbs on rear tires.
Good luck JL222
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Tires are drag radials for Ohio mile and Dyno.
Not sure about that black smoke. The rapid change of rpm may have had something to do with the temp rich condition. From my experience this combo was probably making a bit over 1300rwhp at the higher rpms. That would be about 1700 at the crankshaft.
We went 251 last year with 880hp at crank (probably less 675rwhp). Entered mile 5 at 5900 rpm and gained 0 rpm through the last mile.
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Figured out that the silicone tube connecting the output of the inter cooler to the charge pipe had blown half way off and that is why it only made 7psi of boost which was actually a blessing. Anymore power would have been a very bad thing.
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Very interesting. build. Thanks for all the info!
Wade
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Figured out that the silicone tube connecting the output of the inter cooler to the charge pipe had blown half way off and that is why it only made 7psi of boost which was actually a blessing. Anymore power would have been a very bad thing.
Impressive for 7psi of boost way more hp to come.
We have had the same trouble in the past, blowing off silcon connectors,We welded tabs on tubes and connected it with 1/4'' solid aluminum tubing which we smashed on the ends to make flat and drill holes and wouldn't you know it the one we didn't do coming from blower let lose on the dyno and broke the coil lead to distributor off. We could see the metal in the coil. I epoxied it back on to continue on dyno and it's still in use :-
Drilled hole in blower and tapped hole for bolt and nut + added brace from tube connectors to blower mount.
JL222
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Just a quick update on this car.
Ran at Speedweek 2013.
Tried wider tires, underbody strakes, and spoiler with maximum size spill plates. Ended up keeping only the spoiler and spill plates. That along with 21 psi of boost yielded us 276mph, 278 exit. This qualified us for the 263mph record.(http://img.tapatalk.com/d/13/08/18/ute7e5a4.jpg)
On the record return run, trans did not lock up the torque converter or let us shift into overdrive consequently only ran 240 and failed to back her up.
It appears that the converter actually failed to lock up on the qualifying pass also as I had turned the engine fast enough to be going 305mph. I thought I was spinning the tires but it appears the converter was slipping during the run.
I believe the reason the car did not go into overdrive is that the converter clutch debris contaminated the trans fluid enough to cause the overdrive electric solenoid valve to stick.
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Rob how would that combo do with NO converter?
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I don't think they make converter elimininator for the 4L80e but then we would need a push off.
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Rob......Thanks for stopping by the palace.
I was glad the guards didn't challenge you at the gate.
Wish that 'vet had treated you a little better.
It was my pleasure.
FREUD
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Here is one of the runs from 2013 Speedweek.
http://youtu.be/FiYoaQ_UzM8
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Why is the video private.
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Rob, the video comes up as private and requires a sign in. Some of us don't join any of these other sites. :roll: :roll: :roll:
Pete
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Okay. I think I fixed it. Someone please try again and let me know.
I don't understand how my YouTube loader got changed so that the default setting was "private".
Note how much I had to saw at the wheel of this car to keep it straight. Problem was corrected on following run when we realized the car was squatting about 3" and caused the strakes to drag which unloaded the chassis. Removing the strakes did not make the car stable but it helped a lot.
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It works great now Rob. What kind of camera were you using?
Pete
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Rob,
You look pretty busy!!! Lots of "catching" Interesting with a car that is naturally nose heavy and with the addition of the aft fin work that it was so squirrley, of course it the lower strakes were dragging that could account for some of the wondering. Great job, 276 is hauling a$$.
Rex
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I think it was a go pro.
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It's too bad it took seven runs for us to figure out what's happening. Sort of burned up tires and everything else getting to that point.
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I just watched it -- and I agree -- you did a whole heck of a lot of steering for a run down a straight course :-o :-o. And Floating Island/Mountain seemed to float left and right a bunch of times, too.
Still -- a fun run, wasn't it? Someday I'm going to drive a car down the salt, just to see what it's like. That look on your face at the end of the run while getting your timing slip - proved that it's all good. :cheers: :cheers:
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That wasn't me. That was Ray Vinson Sr. And he is one of the car owners. But you are correct, that's the feeling we are looking for. :-)
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On some good salt, some more chassis tuning, and a bit more boost, I think this car can go 300mph. Also, the converter failed to lock up on the 276mph run so include fixing that in the list for sure.
When I shift this car, I let off the gas completely as the transmission will over run in the lower gears so it does not disturb the tires. I can still shift as fast as a manual box but I believe this method is easiest on the drivetrain. We are still using the stock Corvette rearend and suspension so anything I can do to make that stuff live, I try to make happen.
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Robfrey
Did you have to make any changes to the spindles and hubs to correct the scrub radius with the narrow land speed tires?
Richard 2
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No. Just got the biggest offset we could get on the wheel to minimize scrub radius change..
I used to driving go karts that purposely have huge scrub radius on purpose to give a weight jacking effect and lift inside rear tire. This big scrub radius does not seem to effect high speed stability. I'm not saying that it should not be minimized, I'm just saying that I don't think it is super important because any weight jacking should be minimal as steering angle changes are so small.
I think the instabilities if this car are strictly aero induced. It is actually rock stable at speeds below 200, then it starts to get just plain evil.
Salt was pretty bad at SpeedWeek but the las two runs I made, I could really feel the end plates of the spoiler really working for me at the higher speeds.
You could be on to something though as I can recall when this car was built, we had to move the rack forward and I'm sure it messed with Ackerman a bit.
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......I think the instabilities if this car are strictly aero induced. It is actually rock stable at speeds below 200, then it starts to get just plain evil.....
Not saying for sure that is the problem, but excessive scrub radius can result in what you are feeling. When it kicks in the car can start to dart one way or the other more than is comfortable. The first time I became aware that it even existed was when some guys told me about it with a roadster where it started above 150 or so for them. Any idea how much you really have?
That is a great car and the runs are very impressive. Congrats,
Sum
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Holy Crap how in the world did he keep that thing going straight.... Great job...
Jon
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Corvettes are unto themselves-- I know of one that did away with the front ifs and went to a straight axle and another that may as well have eliminated rear suspension to get it to settle down---and both of these were/are running 50 MPH less than you did.
Sum and I were just recently discussing Door slams. He made the statement that he didn't think he would want to drive a car that he could not MAJORLY play with the air at the back of the car over 200.
I agree --I am not brave or man enough to try to push a car into those speed ranges without BIG tail feathers like George Fields and Hooley's studie.
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Congrats on that 276 mph..cool video. I seen the car at the ohio mile,neat car ..
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Sum,
I'm thinking that minimizing scrub radius matters more for cars with lots of caster. The next time we have it on the scales, I will turn the front wheels as much that is shown on the video and see what kind if effect it has on corner weighting. The one thing that is helping us are we are just using the stock rear spring so it's still pretty soft.
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We finally figured out what happened to the 4L80e transmission that kept us from backing up the 276mph record run.
Apparently the flat towing was an issue as we had some parts that had lubrication issues. John McConnell, our transmission guy and close friend was telling me what he was seeing and he was a little perplexed until I told him how far we were flat towing and then realized what happened.
Now we are wondering how to solve this.
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Trailer :-D
yes I am :cheers:
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Is this a common problem when running automatics?
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Yes, flat towing can cause problems. How far did you tow? 7 miles back to the pits or 2185 miles back to PA?
Geo
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No, just back to pits.
When I run down to the 7 mile mark, I betting it is over 10 miles to the pits.
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No, just back to pits.
When I run down to the 7 mile mark, I betting it is over 10 miles to the pits.
How about from the pits to the starting line? It is amazing how many miles you can put on the salt. If you ran course #2 then it is a long ways back to the pits.
We have saved a lot of time/miles by not going back to the pits if we don't need to like on license runs. 2 runs on Tuesday and 4 on Wed. without going to the pits except for overnight and to fuel up again. Some times if we want to run early in the morning we go and get in line and then let cars go by and leave the car in line overnight.
So is the problem the transmission pump only turns when the engine is turning and thus no lube when being pushed or pulled? Looks like a trailer, dolly or rollback or a manual :-).
Sum
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Does anybody make a free wheeling hub that bolts onto existing hub. Then maybe save a spares?
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Does anybody make a free wheeling hub that bolts onto existing hub. Then maybe save a spares?
racingjunk.com has a set of "towing hubs" for $100.
Don
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Learn something new on here all of the time :-).
(http://i373.photobucket.com/albums/oo175/fast67vellen2o/DSC00570.jpg)
http://www.yenko.net/ubbthreads/ubbthreads.php?ubb=showflat&Number=452693 (http://www.yenko.net/ubbthreads/ubbthreads.php?ubb=showflat&Number=452693)
How easy is the car to jack and change wheels? You will qualify for the record again :-) and will have only so much time to get to impound. No way we could make it in time having to do that also.
How about a tow dolly ....
Old 09-08-2011, 10:50 PM #9
rod
Member
Join Date: Dec 2009
Location: Kingman, NW AZ. in the middle of the longest stretch of Route 66
Posts: 137
Default Re: Free-wheeling hubs-old style towing
i would really lean toward a tow dolly. the free wheeling hubs will only work with certain body styles. with a tow dolly, back the car on the unit, lock the steering wheel straight and go. when home the dolly can be stood straight up and save space. i towed all around the mid west with a tow bar, and would never ever do that again. tow bars are dangerous when raining [don't ask how i know] are hard to back up and have to be designed just right or they will not track.
with the free wheelin' hubs you still have to have the front wheels on the ground, you still have to have a tow ball and light wires. plus all the time to change tires commin' and goin'.
all in all the tow dolly is best hands down.
rod in AZ
rod is offline Reply With Quote
http://classracer.com/classforum/showthread.php?t=33947
... with a 12 volt winch on the dolly tongue or the back of the tow vehicle to pull the car up on the dolly?
Sum
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Running on Course #1 certainly shortens your distance. Usually a much longer wait than #2. I still wouldn't want to chance screwing it up.
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I think we put 400 miles on our tow rig this year. Part of that was to and from the salt but a huge chunk was on the salt. I would opt for a trailer.
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Just get one of those hydraulic arms those tow trucks use and mount it on the rear of your tow car - truck etc
Mount a trailer hitch ball upside down on the center of frame of the Vette in the rear , and tow the car where ever you want with the rears off the salt
G Don
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I think we put 400 miles on our tow rig this year. Part of that was to and from the salt but a huge chunk was on the salt. I would opt for a trailer.
Simplest solution by far.
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I think we put 400 miles on our tow rig this year. Part of that was to and from the salt but a huge chunk was on the salt. I would opt for a trailer.
Simplest solution by far.
All depends on the car. It takes us about an hour and lots of boards to get the Stude on or off of a trailer as low as it is and then we still usually manage to break something doing it :cry:,
Sum
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Sum, with these cars being so low, what happens when you jack the rear?.
Doesn't the front spoiler dig into the gound?.
More complicated than I thought. :-o
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Most low liners and some other cars use a custom trailer or a harnass type system (Costellas cradles come to mind). I will be building something similar to what Varni and Vesco use after realizing the beating our race truck takes flat towing. The wear and tear on tires would be worth it alone.
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Getting the car on and off the trailer is an issue as the nose is very low.
Also, we would have to take two trucks out there to get the trailer out there. Getting expensive.
How about a separate 12v pump that would pump trans fluid from the pan to the test port of the trans that we could turn on during the tow.
For a while there we would start the car and let it idle for thirty seconds or so to pump oil around in the trans but our 16v system is a bit funky and does not charge battery when idling. This would lead to other problems.
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I think your 12v pump sounds like a good idea, wouldn't take much pressure or flow to lubricate. I would check with your trans man to be sure the test port energizes the oil passages it needs to, or where to tap into.
Ron
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Sum, with these cars being so low, what happens when you jack the rear?.
Doesn't the front spoiler dig into the gound?.
More complicated than I thought. :-o
In our case the spoiler is attached with dzus fasteners and comes off very quickly, but yes that could be a problem for some cars. If I was going with the dolly approach that I suggested I'd make one where the tires on the dolly were just a couple inches off the ground (not as high) as a commercial one. That would make it easy to ramp the car onto the dolly and not move the nose down much.
The major negative I see about the dolly is you are towing the car backwards and that would be a pain in the lanes at the starting line. I'd undo the car just before the area where you enter the lanes off to the side and then push it from there. I can't see that short distance being a problem.
I also like the idea of pursuing the pump deal with the transmission guy,
Sum
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Rob,
When I bought my 34 Ford streetrod 14 years ago, it had what looked like a funky driveshaft disconnect on it. The previous owner had towed it behind a motorhome. After looking at the disconnect I soon changed my mind and liked what I saw. Not saying this particular unit would work for you, but it might give you some ideas on what you could do with some Mark Williams parts. Just a thought.
Tom G.
http://www.remcodsc.com/driveShaft.php
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Here is a video of the Vette leaving the starting line. Kind of makes me chuckle a bit. Mind you this is only about 1/4 throttle but when the turbos light, you know it.
http://youtu.be/OiK-X0pIwB0
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What about a bolt on hub adapter with "sleds" for the rear to slide on? Too much weight on the return road?
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What about a bolt on hub adapter with "sleds" for the rear to slide on? Too much weight on the return road?
Luke, I don't think that will work but you did give me an idea on how I could build a cradle with wheels outboard of existing rear tires. It could sit very low, maybe 1" off the ground.we would need to back up on to it, then strap the tires to it. I bet we can barely notice it when we are getting towed.
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Drop deck trailer. They are killer. Drive something low right on, two wheel straps and a rear strap and you are done.
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What about a bolt on hub adapter with "sleds" for the rear to slide on? Too much weight on the return road?
Luke, I don't think that will work but you did give me an idea on how I could build a cradle with wheels outboard of existing rear tires. It could sit very low, maybe 1" off the ground.we would need to back up on to it, then strap the tires to it. I bet we can barely notice it when we are getting towed.
Rob-
That's a good idea. One piece, maybe 2' long with a ramped side to back the car onto. 2 small pneumatic tires per side for balance, you could even add an attachment point for the frame to add a bolt or quick release pin during your longer tows. You could put a hinge with another pin in the middle for easier packing to/from the salt.