[torqhead]

Getting ready to take the car to the track and was wondering what, if any basic changes could be done to ensure I get the car to hook up on launch. I'm planning on picking up a set of MT 295 65R15 drag radials, they're 3455's. I've got a Moser 12 bolt, basically a bolt in and used the factory trailing arms. Would it help to look at upgrading to boxed trailing arms and would that be all 4 of them?

[johnta1]

I would think making it stronger has to help some?

But I think one of the main problems with the factory coil setup is the arms are not placed right for good launches?

Most use some kind of 'No Hop Bars' which relocate the trailing arms.
(not for sure which ones, upper or lower or both)

[gtospieg]

I used global west rear arms...uppers are adjustable if you want to change pinion angle(I didn't) used stock rubber bushings in the housing and the frame side has the delrin inserts. The lowers also have the delrin inserts and are boxed. I also have the braces that connect the upper and lower frame attaching points. I run a stock .875 rear sway bar. I can't make the car wheel hop.

[steve25]

Have you ever been to the track before and made a pass in any car?

Hooking to see how fast your car maybe is one thing, but cutting a good light is a whole other thing!


If your rear trailing arms still have the beat to Hell 50 year old bushings in them, then I would not even waste the time and money to get out to the track looking for repeteable times until I did change out those arms for new ones!

A set of hop stop bars even to this day is one of the cheapest and fastest ways to better hook with a coil spring car.
You can up front unbolt the sway bar end links or faster weight transfer

[Nicks67GTO]

Originally Posted by torqhead

Getting ready to take the car to the track and was wondering what, if any basic changes could be done to ensure I get the car to hook up on launch. I'm planning on picking up a set of MT 295 65R15 drag radials, they're 3455's. I've got a Moser 12 bolt, basically a bolt in and used the factory trailing arms. Would it help to look at upgrading to boxed trailing arms and would that be all 4 of them?

I wouldn't even bother with factory stuff if you're going to be replacing things. Just call up UMI and talk to them about what you're doing. Buy what they tell you to buy. I had nasty wheel hop issues in my GTO until I bought my Currie upper and Lower trailing arms. I installed them and the hop was instantly gone. It allows you to set the proper pinion angle and the Johnny joints allow for bind free movement. Bind is what causes a lot of wheel hop issues. I mention UMI because theyre made in America, will get the job done and are cheaper than my Currie pieces.

[torqhead]

The bushings were replaced in the arms a few years ago and I do not have any wheel hop issues. My biggest issue last year was spinning the tires out of the hole which is why I posted my question.

[steve25]

Don't worry, once you get the tires to hook then you will have the wheel hop issue, lol!
If your street slicks are over a year old even heating them by means of a bit of a burn out may not help you to hook!
We could use some info here!
What cid motor?
What trans?
What rear gears?
How much power is the motor?

[AG]

Adjustable upper CAs to get your pinion angle right and No Hop bars, good for at least low 11s.

[torqhead]

To answer Steve's questions, I'm running a KRE headed 455, 700R4 with Moser 12 bolt 3:73 gears. Chassis dyno showed 535 RWHP and 525 torque. Car is a 69 GTO.

[72LuxuryLeMansLa.]

Originally Posted by torqhead

To answer Steve's questions, I'm running a KRE headed 455, 700R4 with Moser 12 bolt 3:73 gears. Chassis dyno showed 535 RWHP and 525 torque. Car is a 69 GTO.

I don't understand why you would have traction issues with that powertrain........

[steve25]

You really have your work cut for you there!
I don't know what will limit you more at your power level / gearing , not having the needed rear suspension, or not having true race slicks on the car?

If you get 60 ft times near low 2 seconds then concider yourself doing ok for a first time out with traction issues!

About the best simple thing you can do help out 60 ft times is to run 3/4 a tank of fuel, the weight will not do anything for your MPH , but you'll just have to trade off one for the other.

At any rate when you get down to it your first course of action at the track is to confirm the motors tune / plug temp needs if you are unsure that your not already a tad on the safe fat side of things and have no signs of Detonation taking place.

[torqhead]

Last year when I took the car to Bandimere I had a used set of 275 50R15 drag radials on it and spun out of the hole but pulled a 2.118 60' time. Was thinking a taller tire would be a good idea to start with...

[torqhead]

Whoops, wrong number... lol My 60' time was actually 1.959 while spinning the tire out of the hole.

[Tom Vaught]

Sad part about it is finding the working combination.

Example Bill Klausing's 4400 pound race weight 63 Catalina Wagon (Bill K weighed 400 pounds by himself. 6'9" type guy). 455 like your deal, (about the same power) but he worked on the rear suspension. That car would do 1.6+ 60 foot times off the line. So you have a ways to go on tuning. It would also run 12.06 in the quarter.

Tom V.

[torqhead]

Originally Posted by Tom Vaught

Sad part about it is finding the working combination.

Example Bill Klausing's 4400 pound race weight 63 Catalina Wagon (Bill K weighed 400 pounds by himself. 6'9" type guy). 455 like your deal, (about the same power) but he worked on the rear suspension. That car would do 1.6+ 60 foot times off the line. So you have a ways to go on tuning. It would also run 12.06 in the quarter.

Tom V.

I'm about 4200 with me in it, I'm 200 of that. Anyhow, I'm also at a mile high here in the Denver area. I've got the car tuned really well, although I'm going to do one more round on the chassis dyno to ensure I've got the WOT timing set at its best point.

Anyone have any thoughts on whether it will help going with the taller drag radial?

[ta man]

Taller tire will help

[Formulajones]

Originally Posted by AG

Adjustable upper CAs to get your pinion angle right and No Hop bars, good for at least low 11s.

Yup, that's how I setup the factory 4 link coil sprung cars. Along with adjustable shocks, and lower control arms boxed. From there I play with tire pressure and shock adjustments. I've gone low 11's and 1.5 60 foot times with a 275 radial this way. Very simple setup that isn't too expensive, and doesn't compromise drivability on the street.

Have my fathers GTO setup the exact same way, same tire. His old 455 would run the same with nice wheelies. Now with his 571 making 720 HP and 760 TQ I made a couple of adjustments but the same parts. Car should be good for 10's now at 125+. On the street it works really nice, actually does a decent job of hooking and moving considering a dirty street and cold tire. On a prepped track should work even better. We'll see, may tweak more but pretty confident this simple setup will get him down track.

[Tom Vaught]

Originally Posted by torqhead

I'm about 4200 with me in it, I'm 200 of that. Anyhow, I'm also at a mile high here in the Denver area. I've got the car tuned really well, although I'm going to do one more round on the chassis dyno to ensure I've got the WOT timing set at its best point.

Anyone have any thoughts on whether it will help going with the taller drag radial?

Get the car to leave properly and even at 5000 feet you should have some nice times and MPH.
Your car would be a great project vehicle for a belt driven Boosting device.

Tom V.

[torqhead]

Originally Posted by Tom Vaught

Get the car to leave properly and even at 5000 feet you should have some nice times and MPH.
Your car would be a great project vehicle for a belt driven Boosting device.

Tom V.

The goal when I first started building this car in 2004 was to make it new again with a strong normally aspirated factory carb 455 and drive it for another 25 yrs with a little fun at the track here and there. :I've already met that goal calling it official in 2017, but trying to give it the best chance possible to run a decent time/MPH in the 1/4. Sounds like I should get and run the taller tires, although changing trailing arms could improve things, I'm not getting the feeling it would be anything drastic (maybe a tenth?) . If so , I'll do the tires only and go have a blast!

[mrrat1]

How is your front end set up? 90 10 shocks up front will help getting some weight transferred to the rear.