GTOguy

BD104X makes a really, really, good point. Have seen many very nice cars morph into full on race cars over time by a bug-bitten owner, only to later sit, undrivable on the the street. Some of these cars are the owner's very first car, and now they are not usable as cars anymore. That said, what about an axle snubber on the front of the third member flange or some ladder bars to control the axle windup that's causing the wheelhop? And what tire pressure are you running? You need to keep the nose of that diff from twisting upwards.

Overkill69

Thank you....awesome build.
I have a t5 also but I'm not going to install it until I get the hopping and launch ironed out.
I have about as much hp as you. What 60ft did it take to run that et?

65tripleblack

2.155
Launch at only 2500
Slight wheelspin
If I use 15% drive train loss, mine is 486 @ the flywheel.
As stated before, PM Donny Brass. He's a wonderful guy and will be more than happy to help you!

PS: Mine doesn't hop at all. Don't know whether or not IRS is known for hop, as I thought only straight axles wind up to cause that. Sounds like you have something wrong either with geometry or shock(s). Can't see how diff snubber would affect you as the diff is bolted to the frame.

Overkill69

Takes a lot of power to run 12s leaving that soft...
They are known for hop but a different type than a leaf spring. I have good shocks that will stop the hop when stiff enough but then the car has no transfer.Its a balancing act and even just a little change can make it happy. Im considering solid mounting the differential next.

If you match Donnys 1.80 60 ft you'll be close to the 11's but that mindset is how things get out of hand like the other guys mentioned.

63Corvette

I concur.Donny Brass for "stock" drag racing....he is the pro

Donny Brass

Mike,

There is no real voodoo in my rear suspension, and I frequently hang 1.8 sixty foot times on the board with less horse power you are making. I finally hung a 1.79... but I may been on the edge of deep staging with that one.

I will take some pics and post them here later today.

Recipe out back:
Spring: Detroit Eaton 330 pound spring with the leafs clamped hard near the carrier.
Shock: NAPAs finest Monroe equivalents
Strut Rods: VBP adjustable links with poly bushings - important mod
Strut Rod Bracket: later (often referred to as the C3) bracket
1 inch aluminum block between the carrier and the strut rod bracket.
Drag Vette dot com drive shaft and half shaft safety loops

Front suspension:
Springs: original really long small block springs..... the aftermarket replacements are short and to not allow the front end to rise
Shocks: NAPA Monroe equivalents
A-arm bushings: Poly and well greased
Sway Bar: required, but I bet the end links are loose

Tires: Coker bias ply F70-15...please get rid of those 15 year old tires

Launch: let the car bog and pull, it is way too easy to overpower a narrow tire

you can watch some of my in car videos on my youtube site newbomb327 and see how I let the motor get pulled down then hook and go.

you need to get the tire patch flat and perfect during a burnout...... entertain the neighbors until you get a perfect patch, the adjustable strut rods will help you - alignment specs are for road racers

Here is a list of rear end parts I have broken in over a decade of drag racing

" "

Yeah, that is it.


Good luck and keep us informed of how you do, I love reading about other guys running these cars

Donny Brass

Spring clamps





C3 bracket and spacer





NAPA shocks





Half shaft loops

SledgeHammer 2.0

Deep Staging will slow your 60' times and your 1/4 mile times, but shorten your reaction times. Staging "shallow" will give you a running head start and lower your 60' and 1/4 mile times, but it will increase your reaction times.

Donny Brass

I guess I got to get better at self-effacing humor.......

ajrothm

Any chance of fitting a 235/60/15 MT ET street radial on it?

I would still slip the clutch a good bit to keep it from shocking the drivetrain too hard, but the good biting tires should help reduce the wheel hop... Atleast at the HP level you are at.

I run the 255 ET streets, 340lb TRW spring and single adjustable QA1s about 5 clicks from max compression... Mine never wheel hops... However it is an auto and they tend to hop less then stick cars.

I'd definitely set the shocks up to full stiff and limit the squat....that's what will pop half shafts.


I for one, think it's cool you are racing a mid year C2... I like to see "different" kinds of cars run down the strip... However, C2s on the strip was the norm in the 60s....if they could do it then, they can do it now.

I'd follow Donny's advice, he's been doing it a long time dialed in C2

Overkill69

Stiffer valving on the shocks will stop the hop but it also stops the traction. A little drag radial would cure a lot of problems but anything can go fast on them.lol.
A couple things I'm looking at this weekend.
My rear spring is unknown 7 leaf. I lowered it two inches with longer bolts that could be causing problems. I'm going to try to get the rate measured and maybe have a heavy one de arched to set my ride height.

My outer spindles have some free play. I can't wiggle the axle flange by hand but when the tire is installed it's very noticeable. Probably a good source for hopping?

I have parts to correct the camber.
If it won't work after these efforts I'll consider a stickier tire.

This is a blast. My promod racing season is over but we have crazy warm weather so I'm getting a lot of playtime with the 63. I put a Wideband o2 gauge on it and I'm tuning the carb for something other than wot. Never new a Holley could run so clean!

Thanks for all the thoughts.

SledgeHammer 2.0

Heck I make fun of myself all the time.
I didn't say it to criticize you. I have been drag racing since I was 17, I help a lot of people out at the track and the guys I race with are like family. We all help each other out. Last race I had a guy come up to me who couldn't get his Chevelle down the track, since I race a Chevelle, he thought I might know something. He left with more information than one person could absorb at one sitting......

anyway a lot of guys think that deep staging gets you closer to the finish line and will improve your E.T's when it's exactly the opposite.
We index race, with no electronics or transbrakes. In All bracket racing, it's best to barely light the second bulb and not roll further in, It's all about reaction times and consistency and if you roll in you really can never tell how far you roll in each time. We work a lot on reaction times, As I have gotten older mine have really slowed. I am going to a shorter front tire this year hopefully to cut out some of the roll out time.

Overkill69

In my promod car we have the opposite goal on rollout. We run substantial stagger to stay in the beams as long as possible. This season I'm considering tall tires after the effect I saw from rollout last season.
At our local track the tuneup really wadded the rear tires and did not lift the front end like normal. The oil pan or diaper held the beam longer and the 60 ft plummeted. The only way to tell was the reaction time was slow and the mph was a little soft for the ET. The 60 ft was close to a world record so I knew the run was bogus but luckily nobody caught on during qualifying. The next couple runs my driver killed the tree and the 60 ft was extremely fast but possible. The only way I could really confirm the runs were to overlay g meter recordings from a faster track.

they call these runs "diaper draggers" or "hot dog wrappers" because usually some thing is hanging down to prevent the beams from breaking on time.
If the car can pass tech its a good way to set records and qualify hard but I don't think it really gives a heads up advantage except the driver could technically leave early but wouldn't redlight.

c5thriler

Hey Mike saw your location in Prescott I will be moving there in 2017. Bought a lot in Prescott Lakes, Estates section back in 2011 when prices were at bottom and cant wait to get out there. Cant believe how friendly people are.
Have been to a meeting of the Vette Set and have dined with a few of their members as I vacation out there every year since I bought the lot. I still have my first new car bought in 66. Was originally a 390/427 with knock offs, side pipes etc (and raced at Nelsons Ledges & Mid Ohio)but turned it into a restomod with a 600 hp 502, 5 speed Tremec. Too many changes to mention. Have 8" knock offs now with a complete Vette Brakes suspension,offset trailing arms poly bushings & poly front & rear springs etc.
Its not a drag car just a fun street/show car that I scare myself with. Maybe we could meet on my next trip out. Fast cars & boats are my passion!

Brock

Vet65te

Hi Brock - Actually, we've already met at a club meeting about a year ago. I think I already forwarded another Vette owners info that also lives in Prescott Lakes not too far from your lot. Glad to hear you've finally got a date for the move. By the way, none of my cars are serious drag cars either but that never stopped me from taking it out to the track to see what it would do and (knock on wood) never had to 'sweep up' any parts that fell off either .
Mike T - Prescott AZ

L79racer

I didnt want to cut up my 67 so I bought an 80 roller to drag race. I got rid of the 80 and put everything in a 66 to race now. Its a solid axle. I can still put the IRS back in it when I done racing.

C2 Hot Cam Guy

Great advice

427Hotrod

Sweeeet!!

JIM

Overkill69

This should irritate some people for sure...
I saw the auto fab kit. How invasive is it on a c2? I don't really care about extra tire clearance.
Do you have to keep the rear high to avoid hacking up the tunnel?
I'm not against welding some brackets on the frame but cutting any fiberglass starts pushing my morals.

L79racer

Yes I cut up some of the fiberglass as I like the car low and you need some room for the rear to travel. If you keep the car high like when the stock eliminator guys run 29.5x9 or 30x9 slicks you might not have to. Here are a couple of pictures. I run the autofab 4 link. I'm sure it pisses some guys off but dam this car is fun. I saved it anyway. It was a project. 427/425 car originally. Motor long gone.