60 ft blues

[Tim Hensley]

will I was good with all my trying to find my cars happy spot and thought I had found consistent 60 at  3100 15 psi.
I know it has more in it with a small converter change but was happy with the 11.55 ET.
Step 2.New tires and set the 2step for 3100.and I’m good to go work on my reaction time.
Wrong off the 2 step it goes about 5 ft blowers the tires off with 5 failed try’s on Saturday trying a couple of different settings.
Yes I went from 5 year old Hoosier 28/9s to MT PBR 28/9. I figured there would be some differences (for the better I hope)but that was not what I expected.
Made 4 passes on Sunday retracing my steps.
First pass lift at 2800 10 psi some improvement didn’t spin  but 1.9,so I added .4 timing.
2ed pass 1.8 60 but 3 degrees KR on 1-2 shift removed timing even thought it was 10.5 -11 AF.
3ed pass 3000 and about 15 lb boost tires spin was slight but got a 1.77 60 I’m going in the right direction.
I couldn’t decide to add air or take out ,MT tech said add air first if it it got worse take air out.
I thought I just try for a repeat to confirm my findings.
4th try went ok tell the 1-2 shift 14 degree KR stop for the day.Engine appears to be ok think it was false I’ll get the plugs out this week and cut the filter open.


That’s how my weekend went.I run a Hellwig bar set to the stiffest setting,car leaves straight and level no drama, Do we think the bigger HR bar will help me plant the tires better?Or should I think about different shocks.or back to the Hoosier? I do like the MT at speed better
Thank you your time

[TexasT]

Are the rest of the bushings in the rear new? What are others experiencing with track prep? Are you videoing the launch? The five foot out thing makes me thing weight transfer and that it is unloading but hard to know without seeing it

[1 RARE T]

These are Drag Radials?


What kinda burnout?

[Steve Wood]

What The Rare One asked.


Also, I am not a big proponent of two steps, especially on eleven second cars, and would cut it off to get it out of the equation for the moment.


The Helwig bar should work okay in this range, I would think.  I have never been quite sure if the H&R bar was that much benefit on cars in this range, or not.  The old school ATR size bars have worked on much quicker cars.  First thing I would do is to take a good video of the leave from the rear to see if the rear bumper stays level.  If the drivers side hikes up as compared to the passenger side, then an air bag on the passenger side should fix the problem.


I think everyone today understands no tall pinion snubber.  Those work on leaf spring cars only.

[nocooler]

Sway bar isn’t the issue.
If I remember right you were chattering the slicks when the power hit after rolling out. Slicks can recover from that and radials can’t.
Radials need a hard hit and the suspension to separate at the leave to work.

[wmsonta]

Rain keeps me off my bicycle, so here comes my opinions.

You will not get body separation on an A-body or a G-body, oem. The harder the rear drops on the hit, the quicker it will unload. The most successful are able to delay the unload until farther from the hit and at higher speed. 1.0 G's x 1sec = 22mph. After posting a near mathematically perfect time slip and a video of a really nice clean run, you have chosen to fight a losing battle.

Scoobum flogged his bracket car as hard as anybody. His signature shows 6.72 1/8th (about 10.3-10.5 quarter). 1.72 60'.

From memory, you ran 11.55 and 1.67 short. Having been though this, it is possible to spend considerable resources to gain very little.

One of the quickest A-bodies I got involved with (10.9)was a 355 sbc w/a large nitrous button. He would release a trans brake and instantly hit 200+ nitrous. I thought the pass side rear bumper was going to hit the pavement. Hard counter steer for probably 200+ feet. His time/effort/money/my advice got some really nice runs. He also gained a few hundreds of a second.

[Grumpy]

If I remember right you were chattering the slicks when the power hit after rolling out.

wise man advise.. Keep chattering the tires an you will be best friends with the ring an pinion 

[Tim Hensley]

First thanks for letting me vent.
From the top
All bushings are new less than 5 years,track on Saturday was so so fellow next to me with a 10 second mustang 28/10 was struggling 10 second Toyota was hitting his 60 number and ET.


Yes radials first burnout has hard , just easy the rest of the time and it was grabbing hard and pulling rpm down fast.


Should have pulled the 2step out of the mix on Saturday Sunday for sure my bad. Chucked the snubber the first week I got the car.


Best short was 1.70 @ 11.55  three pass very close to these, all three passes at 3000-31 and 3200 between 19 lb -21 lb boost. This is why I set my 2step @3100 to repeat those passes and start working on reaction time
This pic is the 1.7 60 @11.55

[1 RARE T]

Seems to be transferring weight well.


There's not enough air in those slicks.


Lose all those heavy steel wheels and watch E.T. drop.

[TexasT]

X2 on the add air. The wrinkles are good but you could be "driving over them" causing the tire to loose traction. Hard to know with out a vid. I'd start with 3 more psi and see where you are from there.

[Tim Hensley]

Thanks again
Those were the kid Hoosier two weeks ago no pic with the MT
Yes the front wheels should go  but backs only weigh 17 lb each Areo racing wheel
Got three weeks to next race got time to regroup my thoughts

[TexasT]

Have you been to an area that allows for some "laying" of rubber to see what kind of mark you can make with different pressures? You need two nice marks about the width of the tire. two marks from one tire=need more air, skinny mark needs less air to get the full patch down.
A good gauge and an air tank is real handy for adjustments.

[Tim Hensley]

Yes just down the street may get over there soon
I have 20 logs all have this flat spot. What is this?

[Steve Wood]

Looks too rich to me

Does it do with the two step turned off?

[Tim Hensley]

Yes 2 step off and with Alky off and lean
With more timing with base timing 8 lb boost to 25 lb
Tire spin or no tire spin that same flat spot