Help Me Lower My Short Time

[Tim Hensley]

see why you want to work on your short time.
 at 104 your 60 should be 1.4
the track I race at, prep is not to good and a good short times are hard to get at your power level.
The Hellwig bar was my best investment ,but my ET is just 11.8  with a 1.6 60,28-9X15 Hoosier would not hook tell I got the bar,have fun I wont be much help

[motorhead]

Brad - 28x10.5x15 ET Drags, get the stiff walled ones

P/N 3055S

The 28x9 is only a 27" tire.

http://www.mickeythompsontires.com/strip.php?item=ETDrag

The stiff walls are recommended for heavier cars. The sidewall should last the life of the tire - where the non-stiff you can murder it quickly. Wandering isn't an issues with the stiff walls either - and they don't grow as much.

I'd start @ 12-13psi cold and see how they do. It'll end up 15-16 hot.

Make sure the front and rear suspension doesn't bind and that the transmission yoke splines aren't twisted.

Once the instant center and anti-squat are in the ball park the car will hook on any decent tire. As always make one change at a time and see how the car responds.

Thanks Jeremy. I have a pair of 28x10.5's I'm gonna mount up on these lite weight rims...and we'll have a go at it. Price of new slicks up here is insane...so I'll start hunting up a couple pair of used ones again for next year. Gonna pull the air bags and drop the front sway bar...and see how it responds...and then start making changes to the adjustable rear shocks.

[Scoobum]

Brad - 28x10.5x15 ET Drags, get the stiff walled ones

P/N 3055S

The 28x9 is only a 27" tire.

http://www.mickeythompsontires.com/strip.php?item=ETDrag

The stiff walls are recommended for heavier cars. The sidewall should last the life of the tire - where the non-stiff you can murder it quickly. Wandering isn't an issues with the stiff walls either - and they don't grow as much.

I'd start @ 12-13psi cold and see how they do. It'll end up 15-16 hot.

Make sure the front and rear suspension doesn't bind and that the transmission yoke splines aren't twisted.

Once the instant center and anti-squat are in the ball park the car will hook on any decent tire. As always make one change at a time and see how the car responds.

Jeremy, I`ll have to get a price on those slicks from my buddy at the speed shop. This new guy at the front desk at my local tire shop was absolutely clueless as to what I was asking for. The other gentleman that worked there was an ex drag racer...and could locate what I wanted in minutes.

[larrym]

see why you want to work on your short time.
 at 104 your 60 should be 1.4
the track I race at, prep is not to good and a good short times are hard to get at your power level.
The Hellwig bar was my best investment ,but my ET is just 11.8  with a 1.6 60,28-9X15 Hoosier would not hook tell I got the bar,have fun I wont be much help

I just ordered the Helwig bar from my local parts store. $320.00 freight and taxes in Canadian
Looking to see if it helps got some slicks to try too.

[Tim Hensley]

 Scoobum is your short time bad because  you cant get traction when you try to leave harder?
When is started with 255 MT DR I did not have the power off the line to spin the tires but i had a good mph at the top.
I added 1* timing and suddenly the 255 would not hold no mater what I did to the air bags,It took a set of slicks and sway bar
Most people run 10.5 tires because track prep just is not good
Maybe I mist it is it a traction problem or power that hurting your short time

[Scoobum]

I've pretty much run the 9 inch slick exclusively. What I haven't checked...is if it's moving on the rim. I'll be going with the 10.5's...as I've been able to get them to fit without hitting the wheel lip or frame rail. I'm patient when it comes to stuff like this. I'll get it dialed in...and I'm not the least bit afraid to go north of 30 PSI to get it done.

[nocooler]

You'll like the stiff walls - they don't feel like you are riding on pillows, high speed stability is amazing.

On a marginal track - slicks win every time. I hear guys complaining about drag radial not hooking, track isn't prep'd, blah, blah - I get up there and drop the clutch and hang the fronts.

You'll find the weak links in the drive line for sure  

[Scoobum]

I tried a pair of Hoosier 28" DR's...at different tire pressures...an d leaving at different RPM's. Spun 'em the length of the grandstand each time. Went back to the slicks and the car hooked no problem.

[larrym]

How about tune? Less fuel in 1st more timing if it's hooking?

[motorhead]

How about doing it properly? 

[Scoobum]

How about tune? Less fuel in 1st more timing if it's hooking?

Exactly. You can only take what the track will give you.

[Joe Buick]

Which 10.5" were you able to fit without modds Scoobbum?

[nocooler]

How about doing it properly? 

Mike - I don't think anyone is disagreeing with you. I do think he's at the point that relocation will help.

But there are a couple things to consider. What works on one car might not work on another. Power, power delivery (torque converter), tires, track conditions, all come into play.

Brad's times aren't horrible and they were on worn out slicks on a less than marginal surface.

He's stated he wants to start with tires and test, and  make changes as necessary. Plenty of guys have went fast with the stock mounting points - I'd try it before relocating stuff.

With the way winter is going this year he might be racing again in April and that will give him plenty of time to test and get it sorted out.

I guess what I'm saying is he could make a ton of changes now and chase his ass all race season or change one thing at a time and figure out what works best for his car.

[motorhead]

2014 F.A.S.T. and Factory Stock Muscle Car Racing from US 131 Motorsports Park in Martin Michigan

This isn't about making changes, it is about knowing what you have and how it can be changed.  But, if you don't baseline the car's suspension fancy cool-guy tires are just going to mask the underlying issue.  The video at the top of this post very clearly explains the need to tune to either crap tires, a crap track, or both and still be stupid fast with a very powerful car.

In autocross/road racing you do not simply bolt on hero tires and make bonzai runs - you baseline and tweak the suspension to a normal set of tires and work your way up to racing tires. 

To be clear I am not questioning Brad's ability or successes, I am poo-pooing on the Winter-time bench racing session that is happening here about what tires and what tire pressure to run.  Bring the real tech, or at least the knowledge of it...

A set of weld in relocation brackets from UMI are about 1/5" the cost of one slick, and a set of offset bushings for the upper differential ears are $40 from Speedway - hardly a huge investment in time or money.  I say this because the only way to fit a true 10.5" slick under a stock-frame/stock-body Regal is to jack the rear of the car up; and that screws with the geometry.

There are tonnes of fast "small tire" cars who found their success in suspension tuning.

[nocooler]

Last time I checked Mike - 10.5's were small tires  they are nearly the same size as a "true" 275/60/15 - in some cases they are half an inch wider.

I guess we can disagree. The 1st mod to a car that you are drag racing should be a proper set of drag tires. You don't need the biggest set of tires that you can fit - but a set of drag radials or slicks are going to net you the biggest 60' change for the money.

IMO Brad could benefit from the 10.5 tire I suggested due to the stiff sidewall - they don't make a stiff sidewall in anything other than a 10.5 in the 28" tire size.

Could he benefit from relocation? Probably - and he has said he's prepared to buy those parts if the tire doesn't help. Just cause some brackets work on one car doesn't mean they will work on every car at every power level at every track. Having adjustability doesn't hurt but you need to be able to review data and make changes from there. Sure he could plot it out at ride height once he gets his new tires and set everything up to someone's best guess and it might be close, but there will always be tuning needed once he has some data at the track.

If anything I'd start with Baseline's upper relocation boxes. He doesn't need to move the lowers unless the car is lowered or unless he needs more anti squat IMO.

Maybe we should all go back to running southside lowers 

Oh and in case you didn't know different tires will require different suspension geometry's to work.  Drag radial need stupid amounts of anti squat to work at moderate to high horsepower levels.