Is it the power level you have? Too much for the ARB?
CK5
Register an account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members.
I've driven my regal on the road with a spool for probably 15 years now. Maybe you've tried it and you didn't like it, but I find it to be not a big deal at all.
Have you driven a spool on the street before with a 2WD drag vehicle?
The clickers on the QA1 shocks might as well not even be there, they don't have enough actual damping control or real user range. I use and recommend Afco double adjustable for the money. Yeah there are much more expensive options but Afco gets the job done for a decent price and it will actually make a real difference when you adjust it.
Anti Roll Bar - 1-3/4" chromoly from Rhodes Race Cars.
The only preload is the crane in the rear left corner
I will put a drag axle under the next rig I build, this one is keeping 8 lug.
Well you have a 4 link and an anti roll bar, some good shocks and you could really get it dialed to hook.
You running radials or bias slicks?
Obviously get the axle fixed first but if you can't get it to hook the QA1 shocks are the only bottleneck in your setup.
Last edited:
This isn't a 2wd drag vehicle, it's an incredibly heavy work truck with a crane in the back. I don't think comparing it to a light weight drag vehicle is fair. I have driven a heavy 4x4 with a welded diff/spool and with a detroit locker and I hated it. I think that's a better comparison personally. I may try a spool, they're cheap enough, but I think with all the weight in the back it's going to kill my tires and draw way too much attention from squealing tires around corners. It could be something I toss in for a drag and drive, but I'm not sure.
The 4 link doesn't have much adjustability. It's just something I designed and built and guessed at what would be a good roll center/anti-squat setting.
I'm running 28x10.5R17 Bracket drag radials.
I did a 1.42 60' at Northern Michigan when every other car was blowing the tires off. I was one of the few that did a 1 and done there and it was my best ET and speed of the week. I just need to figure out why it won't do that now and everything is pointing to the rear diff.
I almost forgot to mention, I pulled 15° out from the launch and it left. It left so soft I thought it spun so I pedaled it.
[email protected]
I'm going to run 1 more time today.
[email protected]
I'm going to run 1 more time today.
Sorry, I missed this question. It's the shock load from the trans brake. The entire drivetrain goes loose when your on the brake then slams into gear when you let go of the button.
Another good run and I didn't chicken foot it this time!
[email protected], new PB!
Also [email protected] to the 1/8th, that's a PB ET, but not MPH.
The 60' was .13 seconds off the PB of the truck, so if I could get it to go that would have been a 10.4 for sure!
I'm going to leave it at that so I can at least drive it back onto the trailer tonight.
[email protected], new PB!
Also [email protected] to the 1/8th, that's a PB ET, but not MPH.
The 60' was .13 seconds off the PB of the truck, so if I could get it to go that would have been a 10.4 for sure!
I'm going to leave it at that so I can at least drive it back onto the trailer tonight.
My car is 3,740 lbs with me in it, not exactly light, but not as heavy as a crane truck either.
But I do think your shop truck is closer to a car than a lifted 4x4 regarding handling on the road with a spool. My only point is I don't think the spool will be as bad as you think it will be. I don't get any squealing tires, I think that depends a lot on the actual tire. And the antiroll bar keeps it flat, it can't twist up around corners like a 4x4 does, so handling is a non issue really. The only time you really notice negative consequences it is in parking lots, slow speed, it doesn't want to turn as sharp. And obviously be careful around curves on slippery roads. What numbers did you shoot for on IC length and AS%?
Yeah I I agree, a better diff is certainly first before you would upgrade shocks.
Fantastic run, it really liked that additional fuel!
Your truck is awesome and I hope my advice doesn't take away from how awesome it is. I think sometimes I when I try to help people I come across the wrong way, when the truth is I think it's awesome and I just want to help make it "awesomer".
By the way I always wanted to say something but never did until now.
You have a crane on the back driver side.
Did you consider putting it on the passenger side?
Usually the twist from the torque of the engine will let the passenger side tire lose traction and the extra weight can help a little on that side
Truck ran great today, I will post videos when I’m not high on barley pops
I have the itch I want to go fast
I have the itch I want to go fast
- Joined
- Mar 3, 2000
- Posts
- 9,216
- Reaction score
- 7,355
Those are impressive times and speeds especially in that vehicle. Love reading about all the changes being made and how it affects the performance. Lots of learning happening!
Here are the two passes you made.
I'm new to drag racing, but why does it seem like when a car launches the passenger side gets forced down much harder than the drivers side? I know it's from the torque, but wouldn't that also mean that it's pushing that tire into the ground harder than the drivers side?
I could absolutely move the crane, it doesn't matter which side it's on to me.
If I end up replacing the diff I will definitely try a spool. It's only $150-250.My car is 3,740 lbs with me in it, not exactly light, but not as heavy as a crane truck either.
I pulled the cover already and the oil looked minty fresh, no glitter bomb. There was some metal on the magnet, but not more than I usually see after installing a fresh set of gears. I'll probably pull the diff tomorrow and tear it down so I can see the torsion gears and verify it all looks good. I can't imagine it was good on the diff to spin that tire all the way into 3rd gear, it must have been going about 250mph.
Now I'm leaning on the issue being the rear right tire wadding up because so much weight is shifting to it with the harder launch. I may just need to put more air on that side, it's already at 25psi, but they wrinkle up nicely. Unfortunately I always try to get the left lane so Amber can film easier, but we're going to look through all the slow-mo footage we have and see if we can see the passenger side tire in any of them.
This happened once in Michigan when we turned up the 2 step to 3200rpm, but there it blew the tire off and didn't even try to move the truck. Every time it spun the right rear this time was about 1-2 feet out just as the front tires were coming off the ground. I'm thinking it's a combination of the poor track prep and the harder leave with the trans brake.
I don't remember and I ended up adjusting the ride height lower after I set them up initially. I know this is somewhere I could really make improvements so it's likely I'll be making some changes to add adjustability here in the near future. I can also just adjust the rear ride height at launch to change the angles, it would probably hook better with the rear end up another inch or so.
If I can get the 60' down into the 1.3Xs I think I'll be able to sneak into the 9s which is as fast as I want to go with this truck for now. My experience with the QA1 shocks is different than yours for sure though. I can definitely tell the difference between a few clicks here and there. It has 36 position adjusters so I usually make a big swing like 4 clicks. I put 6 clicks in to rebound on the front to slow it down over what we have for road driving. I picked the truck up on my lift 20 minutes ago (no air in the bags) and the front shocks still haven't fully extended. That usually only takes about 5 minutes with the street tune in them.
Thanks for your help looking over my logs! Don't forget to send me the bill.
The truck is incredibly popular and draws a ton of attention. People want to come tell me how I could make it even faster by doing X or Y (usually taking the crane out) and my answer is usually "If I did that, you wouldn't be over here talking to me." I've always tried to keep the utility of the truck intact, so that squashes most of the ideas I get from other racers. The only thing I've seriously considered is making the bed sides removable with T-pins. That would shed a couple hundred pounds without changing the looks of the truck much.
I'm already starting to think about what vehicle I want to build to put this engine and transmission in so I can do 7's in a drag and drive style rig. I plan on rebuilding the 6.0 into a 406 and either turbo it or just run it 12:1 and spray some nitrous when I want to take it to the track. I also have a T-6060 that may go in when I swap the drive train, either that or I'll build another 4L80E.
I really didn't take any pictures, but we got videos of all the runs that I need to get processed and posted. The event was an absolute blast, I thought it was so much better than when it was at Tucson, the Firebird facility is just so much nicer. We partied with new friends for 3 nights, had 15 hours of open lanes which made the lines way shorter than when we were in Tucson, I think there was only 3-4 hours a day of test and tune there so everyone was trying to race at the same time.
If you're at all interested in the event, go. Make it even better and get a 2 day camping pass so you can walk around all night drinking beers and talking cars with a few thousand new friends.
I went frame by frame and tweaked the settings so I could see the other sidewall somewhat. it does look like the right rear is wadding up more than the left rear just before it breaks loose. If anyone knows more about radials drag tires than I do, let me know what you think. You see quite a few large wrinkles going down the front of the tire like I captured in the picture just before it breaks loose.
There's a Friday night drags this Friday, so we may go out and do some testing and slow mo capture from the passenger side.
What is happening is the torque from the engine is trying to twist the axle, so it is pushing the left tire down, and lifting the right tire up. This gives the illusion that the right side is being pushed down, but what is actually happening is the tire is lifting up, so there is less weight on that tire, which is why with a one wheel peel the right rear usually spins if traction is equal.
I think you should try a spool and see if it will work for you. Every limited slip still has a limit that it will slip at, and once it slips, it won't recover until you let off.
When I see that I think it was probably hard on the tire.
That tire could be toast, you overheat the tire and it might lose its performance. How many passes are on them? The smaller the tire, the faster and heavier the vehicle, the less runs you get. Once the 60 fts start to drop I replace the tires, which is usually before I hit the treadwear marks. You may only get 30 - 50 runs out of those tires with that fast heavy truck, especially with that short sidewall on the 17 inch rim. If the sidewall goes away, the tire won't work right anymore.
I go back to what I said above on the tire above. 25 psi seems like a lot, they certainly don't look like they have 25 psi in them, what does your truck weigh? What is the rear axle weight? I think the shorter sidewall must take more pressure too. You may just need new tires.
I shouldn't of said the clickers might as well not be on there, I was exaggerating, sorry. The clickers work, but they certainly don't have the range of an Afco and if you start pulling wheelies you likely won't be able to tune the bounce out like you can with the Afco.
No problem! Glad to help! When I was suggesting more fuel I wasn't just trying to make it go faster, though picking up 9 MPH is certainly significant, that's a lot of HP. But what I was trying to do is help you find the safest, most reliable tune. And to do that, you need to find where it loses power, both with timing and fuel. The most fuel and the least timing will be the most reliable. But that kind of tells me the fuel is quite lean because when you are close to optimal, often changing it a few percent one way or the other will barely show a performance change, if any at all. Plus what it liked on the dyno is not always what it wants at the track. I would certainly try more fuel off the nitrous as well to see what it wants. If you can get close to max performance with the most fuel and the least timing, it's going to last the longest is can. If it was a NA high compression race engine, lean is mean(to a point), but with a boosted LS on E85, you want to run the most fuel it still performs good with.
I have thought that many times myself, if I had my 632 BBC in a lighter car, it would go 8s on motor alone, with that heavy car it only does mid 9s on motor and I have to spray it into the 8s. Then again if I had high compression and race gas or E85 it would be faster too, I have only been spraying on pump gas, which is a small shot. There is always something to go faster, but I got to be honest, I had just as much fun when it was a 10 sec car than when I built it as an 8 second car, and I drove it more often before it had the cage. Your powertrain would certainly be much faster in a car. I can do the quick math for you in my app if you want to know very closely.
Glad you had fun! It was an awesome weekend for you, it know it feels good to get a new PB!
Thanks for the explanation, that makes sense now.
If the diff is hurt I will try a spool. My concern though is that with the spool, front tires up right tire spinning, I'm going into the other lane. Having the one tire spin seems safer to me, but having the diff explode at the 120mph is also not a fun thought.
I bought these tires new with the bead locks. They have maybe 15-20 runs on them.
I plan on trying more pressure. The truck weighs ~5600 lbs without me in it, 5830 with me. I haven't managed to find a set of affordable race scales that can weigh the types of vehicles I tend to make, so I don't know what the front/rear split is.\
With the QA1 shocks I can tune them where I can take a "speed hump" in my truck at 35-40mph and it feels like nothing. Having them set that stiff makes the ride extremely harsh so I back out a couple clicks to soften it up for the road. My base drag race shock tune adds 4 clicks to rebound in the front and 4 to compression in the rear. I'm sure the shocks you are recommending are great, but I'm not ready to give up on these yet.
I understand that, but getting a private track rental where I can go and do 10-20 runs in a single day isn't something I can do right now. I just have to get runs when I can and unfortunately the track conditions and weather change greatly every time I'm at the track so it's hard to do A-B comparisons. That and the truck hasn't been reliable so it's months between runs and major changes happen every time it goes down. I'm getting it to where it needs to be and then I can start tweaking the tune.
The amount of power and equipment the truck has now has actually reduced it's utility. It's fun and awesome, but its pretty expensive to drive, plus the pistons are pretty loose so you have to let it warm up before you can drive it anywhere. My comment about going 7s would also include swapping the 3.0 whipple for the 3.8 . It will bolt right onto my intake manifold.
