need help with 1/4 mile times....

**Poppn** · 09-10-2009, 10:17 PM

was at the track last night and have a problem....

I'm trapping a 90mph 1/8 at 8.9, but can only pull another 13 or so mph but the 1/4 at 13.7s

what the hell is wrong??

here are 2 slips to compare to.

This is my personal best run.......

60 foot-----2.05
330--------5.75
660--------8.75 MPH 90.65
1000-------11.30
1320-------13.46 MPH 104.82

This is last night's best.......

60 foot-----2.24
330--------5.94
660--------8.95 MPH 90.12
1000-------11.52
1320-------13.70 MPH 103.32

Mods are catback with a cutout, LCAs, lid, ls7 clutch with new hydraulics.

Why is my car dying out after the 1/8???

**FasstChevys** · 09-11-2009, 03:52 AM

Well - your '60 foot time tells a lot -

Two tenths slower in the '60 is worth another tenth slower at the end as well, case in point:

13.46 slowing down almost exactly 3 tenths to a 13.70 sounds about right to me.......

**86 IROC-Z** · 09-11-2009, 07:05 AM

Get an auto.

**FasstChevys** · 09-11-2009, 07:06 AM

Originally Posted by 86 IROC-Z

Get an auto.

& drag radials

**tnthub** · 09-11-2009, 07:55 AM

Sixty foot times are horrible. Buy some sticky tires and work on your shifting.

Heck, I only run about 90 in the 1/8 but the ETs are 7.4-7.6.... It is all about efficiency, gearing, and shifting.

**0rion** · 09-11-2009, 10:53 AM

Yeah, I think you're looking at the wrong mph for the 1/8. That's a large mph for your times. I ran a 90mph in the 1/8 today and finished with an 11.89 in the quarter.

**Poppn** · 09-11-2009, 11:05 AM

sorry for the blurry image, my iphone sucks balls at close ups

**c5z28** · 09-11-2009, 12:07 PM

Originally Posted by Poppn

sorry for the blurry image, my iphone sucks balls at close ups

looks like your blowing the tires between the 1-2 pull. My 12.95 pass
60' 2.013
330' 5.533
1/8 8.375
mph86.74
etc.

I have gotten down to 1.94 on my 60' with stock 16", let out the psi to at least 25 psi my optimum is 20psi. Could you feel the back end chirp when you shifted for second?

**86 IROC-Z** · 09-11-2009, 12:10 PM

Originally Posted by Poppn

sorry for the blurry image, my iphone sucks balls at close ups

lol @ reaction

**Poppn** · 09-11-2009, 12:22 PM

Yea the starter was being retarded and I didn't have enough time to do what I needed before the run....sooooo I just waited as long as I needed at the
tree to try and get a good launch

**Hi-Po** · 09-11-2009, 12:55 PM

Thats exactly it, if you have too... get up there, stage... and eat a fucking samwich if you have to. Get yourself ready, screw reaction times when your trying to get something else right. Ticker doesnt start until you move

**Poppn** · 09-11-2009, 12:58 PM

Originally Posted by Hi-Po

Thats exactly it, if you have too... get up there, stage... and eat a fucking samwich if you have to. Get yourself ready, screw reaction times when your trying to get something else right. Ticker doesnt start until you move

Exactly, I have some reaction times as high as 2+ seconds haha

**Poppn** · 09-11-2009, 01:01 PM

Originally Posted by c5z28

looks like your blowing the tires between the 1-2 pull. My 12.95 pass
60' 2.013
330' 5.533
1/8 8.375
mph86.74
etc.

I have gotten down to 1.94 on my 60' with stock 16", let out the psi to at least 25 psi my optimum is 20psi. Could you feel the back end chirp when you shifted for second?

I have bad wheel hop in 2nd 3rd and one run even 4th (ls7 clutch ftw). I know that is a contributing factor to my times, I'm just perplexed act the lack of accelerationon the back half of the track.

I also aired the tires down to 25 as I forgot my airpump and still needed to drive the 100 miles home from the track.

Relocation brackets are next.

**Hi-Po** · 09-11-2009, 01:02 PM

Originally Posted by Poppn

Exactly, I have some reaction times as high as 2+ seconds haha

Your a better man then I am then. The guy I go with is constantly telling me to take my time, tells me to eat a samwich when the light turns greens and concentrate. I race so many Mustangs, I cant let them win and look bad for the fbody family. So I hurry and screw my 60' up.

Looks to me, you need to play around with your shift points.

**c5z28** · 09-11-2009, 02:17 PM

Well op sounds like you know whats wrong then good luck.

**GTP231** · 09-11-2009, 03:32 PM

Only issue I'm seeing that hasn't been brought up is gearing. Its prolly a big part in your dismal 14 mph back half increase

**Poppn** · 09-11-2009, 03:41 PM

Originally Posted by GTP231

Only issue I'm seeing that hasn't been brought up is gearing. Its prolly a big part in your dismal 14 mph back half increase

I guess so, it's a T56 with the stock 3.42s though, so I dunno

**c5z28** · 09-11-2009, 05:39 PM

3.42 gears don't keep m6's from hitting bottom 13's.

**0rion** · 09-11-2009, 05:44 PM

that 1/8 mph is great but I have a feeling if you hook the car up that mph is going to drop but your times will improve greatly. That 60' time just flat out sucks. Fix that issue before you worry about your mph. You fix that 60 and you're looking at some decent runs. A rule of thumb is for every tenth in the 60 you gain it's almost 2 tenths on the big end. Get that 60 in the 1.8x range and your times will drop like a rock.

**cuzimoto** · 09-11-2009, 07:03 PM

I'm betting clutch. Last year I was racing PSCA event. Last two rounds I was losing mph at top end just like you. (usually pick up around 25mph). I thought I was running out of nitrous. My 1/8 mile times were still consistant. I drove home and parked the car. Next weekend went to pull out of garage and barley got out the driveway cause the clutch was bye bye. I'm willing to bet on it. Any one giving odds.

Your 60 foots and reaction times ain't got squat to do with your trap speed.