Fist time out with Whipple/6speed/IRS

[Jmurrz]

Hey guys, I just had my first time out on the track with the cobra (second time ever actually). I am just curious what you think of my times. My goal for this year is a 10.99. Any pointers would be great!

I know I need to improve my 60' but I am trying to figure out how hard to launch. My best time was a 1.852 leaving at about 3000RPM dumping the clutch. I am running 26x10.5 Et Streets. The tires hooked well with about 14psi in them, and I think I can launch higher with better results. I also am going to shift faster, I was granny shifting just because I was still getting used to the car on bias ply tires and wanted to know if it would sway top end (thankfully not much). I just bought a N2MB WOT box with no lift shift, so that should drastically help me improve shifting. I am still on the street 93 tune making about 580HP and I trapped 121.

My tuner (Kevin Hand) said if I wind it out to 6700 or so I should pick up some top end as well.

Just curious what else some of you seasoned racers would recommend! Thanks guys!

 

[stangfreak03GT]

I ran 12psi in my ET Streets. Need more RPM at the launch, at least 5K.

 

[Jmurrz]

I ran 12psi in my ET Streets. Need more RPM at the launch, at least 5K.

I am just worried about breaking half shafts at that point. I will definitely bump it up to 4k launch and drop the pressures to 12psi though! Thanks for the input!

 

[AMWill]

Hey guys, I just had my first time out on the track with the cobra (second time ever actually). I am just curious what you think of my times. My goal for this year is a 10.99. Any pointers would be great!

I know I need to improve my 60' but I am trying to figure out how hard to launch. My best time was a 1.852 leaving at about 3000RPM dumping the clutch. I am running 26x10.5 Et Streets. The tires hooked well with about 14psi in them, and I think I can launch higher with better results. I also am going to shift faster, I was granny shifting just because I was still getting used to the car on bias ply tires and wanted to know if it would sway top end (thankfully not much). I just bought a N2MB WOT box with no lift shift, so that should drastically help me improve shifting. I am still on the street 93 tune making about 580HP and I trapped 121.

My tuner (Kevin Hand) said if I wind it out to 6700 or so I should pick up some top end as well.

Just curious what else some of you seasoned racers would recommend! Thanks guys!

Beautiful car and awesome times Jmurrz!

You definitely have the MPH for an even better time and I'm sure you'll get it soon!

I went 11.98 @118 in my personal 2014 GT so you'll definitely pick up a few tenths!

Looking good!

-Will

 

[IronTerp]

I am just worried about breaking half shafts at that point. I will definitely bump it up to 4k launch and drop the pressures to 12psi though! Thanks for the input!

I ran these exact tires with my Terminator for a bit and eneded up going with what Stangfrak recommended above. I hit a couple of high 1.5's and mostly low 1.6's with the 4,500-5,000 launch and 11-12 psi in the tires. these can get a little squirrely at times though. And the slick itself will absorb a lot of the shock of the launch and protect your halfshafts. I broke two over a three year period trying to get drag radials to hook. Ran slicks for the last four years I had the car and not issues.

Get back out there and you'll get your 10!

 

[broke7]

Bring the launch up to 4000-4500, slip/dump.


Keep the tire pressure there if its hooking, go as low as 11-12psi if needed for track conditions.

Good cooldowns, 30-45 mins with fans on it (if you have a gen)erator or electric hookup) I use a carpet blower and a honda 2000 generator for mine.

Run intercooler pump intermittently while cooling down to circulate stagnant IC fluid in the core.

Shift the car at 6200-6300.....

Ice in the tank if you have one capable of doing it.....


Its a trial and error game, that will get refined the more and more you make passes. MOST IMPORTANTLY Take notes on setup, weather etc.

 

[Jmurrz]

Beautiful car and awesome times Jmurrz!

You definitely have the MPH for an even better time and I'm sure you'll get it soon!

I went 11.98 @118 in my personal 2014 GT so you'll definitely pick up a few tenths!

Looking good!

-Will

Thanks Will! If you ever plan on going to Island let me know!

I ran these exact tires with my Terminator for a bit and eneded up going with what Stangfrak recommended above. I hit a couple of high 1.5's and mostly low 1.6's with the 4,500-5,000 launch and 11-12 psi in the tires. these can get a little squirrely at times though. And the slick itself will absorb a lot of the shock of the launch and protect your halfshafts. I broke two over a three year period trying to get drag radials to hook. Ran slicks for the last four years I had the car and not issues.

Get back out there and you'll get your 10!

Thanks for the tips! I will try a 4500 dump this Friday and see how it goes! I felt the tires get a tad squirly a few times but nothing too crazy.

Bring the launch up to 4000-4500, slip/dump.


Keep the tire pressure there if its hooking, go as low as 11-12psi if needed for track conditions.

Good cooldowns, 30-45 mins with fans on it (if you have a gen)erator or electric hookup) I use a carpet blower and a honda 2000 generator for mine.

Run intercooler pump intermittently while cooling down to circulate stagnant IC fluid in the core.

Shift the car at 6200-6300.....

Ice in the tank if you have one capable of doing it.....


Its a trial and error game, that will get refined the more and more you make passes. MOST IMPORTANTLY Take notes on setup, weather etc.

I really didn't even think about cool down too much. That time slip was produced with a back to back hot lap. I will try to see if I can get a fan of some sort, and I will look into what I would have to do to put ice in the tank.

As far as shifting goes, I will try both revving it out and shifting where you recommended to see what works best for me!

Thanks Everyone!

 

[Mr.Venom]

Whats your elevation and what were you shifting at before? 121mph is a little low.

 

[Jmurrz]

Whats your elevation and what were you shifting at before? 121mph is a little low.

Elevation is 511.8 ft. I was wondering if my trap speed seemed a little low. The car made 580WHP SAE a little over a month ago on Wicked Motorsports Dynocom. I was shifting around 6300-6400RPM

 

[Jmurrz]

Elevation is 511.8 ft. I was wondering if my trap speed seemed a little low. The car made 580WHP SAE a little over a month ago on Wicked Motorsports Dynocom. I was shifting around 6300-6400RPM

Anyone have anything to add? getting a bit concerned with my trap speed. Would granny shifting really make such a big difference MPH wise?

 

[Shadow Grey 03]

Anyone have anything to add? getting a bit concerned with my trap speed. Would granny shifting really make such a big difference MPH wise?

Yes, it does.

 

[Mach828]

Trap speed is pretty low. I trap the same at less power and at 6,000ft. Maybe it was pulling some timing?

If you bring the launch rpm up then just be sure to slip the clutch. Helps decrease stress on the drive train. With the low end torque from the whipple you really don't need a high rpm launch to 60 well.

 

[Jmurrz]

Yes, it does.

That is somewhat good news. When I say I was shifting slow, I was shifting SLOW.

Trap speed is pretty low. I trap the same at less power and at 6,000ft. Maybe it was pulling some timing?

If you bring the launch rpm up then just be sure to slip the clutch. Helps decrease stress on the drive train. With the low end torque from the whipple you really don't need a high rpm launch to 60 well.

I doubt it was pulling timing, It was a pretty conservative tune because that is my normal street tune. I am thinking about swapping pullies and running the race tune just to make sure I am trapping where I am supposed to.

I am not too worried about the drivetrain, I think it will be okay dumping under 4k but I don't want to try my luck dumping any higher than that though!

 

[Five-o-Joe]

Yes, mph is definitely low IMHO. My car made 596 and ran 103 in the 1/8th with 18s front and rear.

But I've raced stick cars only for ~20 years and I do NOT shift slow.....lol.

 

[IronTerp]

Anyone have anything to add? getting a bit concerned with my trap speed. Would granny shifting really make such a big difference MPH wise?

The trap speed is actually pretty consistent with your ET, just not with the 580 RWHP that your Whipple is producing. But, it's not that far off that driving performance, track prep, and Density Altitude considerations couldn't be conspiring a bit here. Like Broke said, getting out there and getting more runs in under your belt would be a big help.

 

[Jmurrz]

Yes, mph is definitely low IMHO. My car made 596 and ran 103 in the 1/8th with 18s front and rear.

But I've raced stick cars only for ~20 years and I do NOT shift slow.....lol.

That is what I thought, MPH wise I am way low. Its not that I cant drive, I have a problem with my shifter. It went into 2nd a few times when it was supposed to go into fourth. Kevin noticed it on the dyno (he went into 2nd by accident twice) and tried to shim it out a little bit. Ever since he told me that I was afraid to bang any gear. I've since got some confidence on the street and it seems like it has remedied itself. I think the WOT box has helped out too for some reason.

The trap speed is actually pretty consistent with your ET, just not with the 580 RWHP that your Whipple is producing. But, it's not that far off that driving performance, track prep, and Density Altitude considerations couldn't be conspiring a bit here. Like Broke said, getting out there and getting more runs in under your belt would be a big help.

That makes me feel much better. I am going to go back this Friday to see what I can do WOT shifting with better cool downs. I guess I should have mentioned it before but that time was a back-to-back hot lap. It was my best ET but I think if it wasn't hot I could have made much better trap speed.