Track results, time to switch to 28" tire?

[Snorman]

Braved Mother Nature last night and went to Atco. It was probably the best track visit I've had since the days when I used to go to Cecil County on Saturday mornings in the fall/winter.
Combo is a TA49, blue tops, Mease DP, Hooker catback, 2800 Pro-torque convertor, big neck IC. I'm running a Turbotweak 110 chip with TCC lockup at WOT around 75-80mph. I'm running a 26/10.5-15 ET Street at 16psi on stock T-wheels with stock sized front rubber.
Previously, the car went 12.07@110.73 at E-town. This was on 100-unleaded with no TCC lockup.
Here's the 1st pass last night...easy launch, lifted through the traps a bit due to a piece of debris on the track

60'---1.739
330'---4.925
1/8---7.631
MPH---90.30
990---9.935
1/4---12.016
MPH---111.77

2nd pass, now I'm getting confused...

60'---1.750
330'---4.988
1/8---7.703
MPH---90.12
990---9.987
1/4---12.033
MPH---113.98 (2.2 more mph, still a 12.0?)

3rd pass, the confusion grows...

60'---1.701
330'---4.957
1/8---7.686
MPH---89.59
990---9.979
1/4---12.029
MPH---113.92

4th pass, bad launch...

60'---1.825
330'---5.075
1/8---7.785
MPH---90.20
990---10.060...ugh...
1/4---12.095
MPH---114.76 (Still a 12.0?!?)

The car is running damn near 115mph now, with a not-horrible short time and still going 12.0's.
The only thing I can figure is that the car is now nosing over 100-200 feet before the traps and it's time to go to a taller tire. The valve springs are stock, but I have a set of (nicely ) ported heads to go on the car, so that issue will be addressed. I just wanted to get into the mid-11's before moving on to bigger and better things.
That mph should get me 11.6's, confirm my suspicions that I've run out of gear and need a taller tire.
Thanks!
Sean.

 

[blackshoebox]

Nice times...

I would try a 28 inch tall tire. However, you may have to launch the car harder in order to get the bigger tire moving, especially with a 2800 stall converter. Some cars have picked up from the bigger tire, and some have slowed. Was the tune good all the way through the traps? Not getting lean at the top at all?

 

[Snorman]

Tune is good. These blue tops have to go 100% to keep up with the combo, so I know I definitely need more injector. That'll be addressed when the new turbo/IC and heads go on in the next few months. I see KR on the launch due to the slight wheelspin I'm getting, but by 2nd gear, the KR is dropping to 0.0 and the O2's settle into the mid-700's. I really think I'm going to put an EGT on this thing, but I know right now I'm on the edge with these little injectors and 115mph.
I'm launching at ~5psi right now. I did hit 6psi on the 1.70 last night, but couldn't replicate it. Next pass at 6 and it turned over the tires once or twice. I tried dropping the pressure to 14-15psi and it seemed to load them, bounce and when it unloaded they spun. A friend was there with me running his 'Stang, and he said the car leaves very straight and very clean.
I just think I'm running out of RPM, and that's killing my ET.
Maybe a 28/11.5 ET Street and 7psi might do the trick?

I almost can't believe it...nearly one year ago I made my first pass in this thing at E-town...16.9@94mph. 35 or so passes later...
S.

 

[blackshoebox]

Originally posted by Snorman
Tune is good. These blue tops have to go 100% to keep up with the combo, so I know I definitely need more injector. That'll be addressed when the new turbo/IC and heads go on in the next few months. I see KR on the launch due to the slight wheelspin I'm getting, but by 2nd gear, the KR is dropping to 0.0 and the O2's settle into the mid-700's. I really think I'm going to put an EGT on this thing, but I know right now I'm on the edge with these little injectors and 115mph.
I'm launching at ~5psi right now. I did hit 6psi on the 1.70 last night, but couldn't replicate it. Next pass at 6 and it turned over the tires once or twice. I tried dropping the pressure to 14-15psi and it seemed to load them, bounce and when it unloaded they spun. A friend was there with me running his 'Stang, and he said the car leaves very straight and very clean.
I just think I'm running out of RPM, and that's killing my ET.
Maybe a 28/11.5 ET Street and 7psi might do the trick?

I almost can't believe it...nearly one year ago I made my first pass in this thing at E-town...16.9@94mph. 35 or so passes later...
S.

Mid 700's is about as lean as you want to go. The car may pick up a little bit of mph, if it was more in the high 700's to low 800 range. Try the 28's and harder launch and see what happens. A local guy went 11.9@113.5 with a 1.65 60 ft on 26's and a 12 psi launch, so you are right there..He also had a similar combo to yours..

 

[ttypewe4jim]

dude i think that the only reason that you are not in the 11s is beacuse of your 60 foot......we run the same tire and even and i manged to get a 1 61 60 with a 11 pound launch down at cecil......that was on a 12 90 run also thoose tires should be able to hook and take you into the 11s


what kind of lca's do u have?


hth (even know it wasent just info )
jim

 

[Snorman]

100% bone stock suspension.
There's no way I could launch at 11psi. The brakes would hold, but I'd probably get 10 feet out and destroy the tires. That happened last night when I tried much over 5psi.
Even then...a 1.70 short time isn't that bad. With 114mph, I can't figure out why I don't have an 11-second slip in my pocket. Especially considering I've gone 12.0's with 111mph on a similar short time.
S.

 

[blackshoebox]

Originally posted by azgn
well, the 60' time is everything!
the 1/8 mph looks low for your final mph

Whats wrong with 1/8 mph? That mph for the et, looks perfect to me. If the 60 ft, goes down a hair, he is in the 11's, with a text book pass IMO. Most guys pick up about 20-25 mph after the 1/8th, so he is right on. I think his 11 second time slip lies in a bigger tire and a better launch.

 

[Snorman]

azgn,
The tranny seems fine, it was done by Eric @ Dynotech last December. I'm going to a looser converter when I make the changes I mentioned earlier and he'll take a look, but he didn't even recommend stepping up to billet parts until it starts to flare or slip. Shifts are hard and firm, doesn't flare...seems good. Would there be any other symptoms of a slipping tranny that maybe I'm missing? What should I see on the SM on shifts?
I do agree...something just seems strange. It went within a few hundredths even with a variance of 3-4mph on a similar short time. Look at the 3rd pass. I dropped .038 off the 60', ran 2.2 mph faster and still went .013 slower!
So nobody really thinks I just need a taller tire?
S.

 

[Snorman]

C'mon boys, keep the arguing in the Lounge.
I need to get my 11 before I can go any faster.

S.

 

[86brick]

Originally posted by azgn
well, you would be the expert.....so just disregard my input

in fact I'll just delete my post

BTW, how many 11 sec passes you got?

Woody, is it that time of the month for you? I only ask cause you seem to be very moody like women get with PMS.....

Snorman, congrats on the new best passes! You definitely have a high to mid 11 second pass in that car with a 1.7-1.6 60'.....If I were you I'd get some 50lb injectors cause you really don't want the Duty Cycle to go over 80%..... I hope to get my car running like yours once I get the 3" DP installed as well as some Duttweiler IC necks or that new Mease 24 row stretch! Working on the suspension (a few basic mods) and getting some real tires is also on my to do list

Later.

 

[86brick]

BTW, there is a car down here very similar to yours (only difference is he has a TE44, a Spearco FMIC, and the stock D5 converter) and he runs on 28 X10.5" ET Drags..... Car has run 11.60's @115mph with a 1.67 60' Try the 28's and also a nice E-brake high boost launch!

 

[Snorman]

Play nice...keep it in the Lounge!!!

Yup...these bluetops are at 100% at WOT according to Eric. There's nothing left, so touching the boost is out of the question. I need to get it with hook and driving. That Mease IC is nice, I'm thinking of one for my new combo.
I dunno', after last night I'm having a hard time believing I can get a 1.6 out of these tires...even though there are plenty of guys doing it. Thing that sucks is there are no 28" DOT's that'll fit a stock T-wheel, and I like to play "sleeper". Honestly, I get a kick out of it because the 26/10.5's look like stock tires from a few feet away.

S.

 

[86brick]

Originally posted by Snorman
Play nice...keep it in the Lounge!!!

Yup...these bluetops are at 100% at WOT according to Eric. There's nothing left, so touching the boost is out of the question. I need to get it with hook and driving. That Mease IC is nice, I'm thinking of one for my new combo.
I dunno', after last night I'm having a hard time believing I can get a 1.6 out of these tires...even though there are plenty of guys doing it. Thing that sucks is there are no 28" DOT's that'll fit a stock T-wheel, and I like to play "sleeper". Honestly, I get a kick out of it because the 26/10.5's look like stock tires from a few feet away.

S.

Just put 28 X 10.5" M/T ET Drags on the stock 7" T-rims (they fit with spacers as seen on Jane's car in GMHTP) and drive very slowly to the track

 

[blackshoebox]

Originally posted by azgn
BTW, how many 11 sec passes you got?

About 30. And another 25 in the low 12's. And will be getting some in the 10's, within the next month.

 

[tonka]

Hey Snorman, looking at your times I see that the better you hook off the line, the slower you are at the 330 ft. You seeing some serious knock at the launch that is pulling timing on you or something? Comparing your first and third runs, you start off with a .038 second advantage with the 60 ft time, and have fallen to a .032 deficit by the 330 ft mark.

 

[Snorman]

Actually, yes.
I see a few degrees (2-4, depending) on launch and by the time I hit 2nd gear, it's gone. In 3rd I'm at 0.0* of KR. I've attributed it to the force of the launch and slight tire spin in some cases.
Is the KR possibly causing this strangeness?
S.

 

[turbojimmy]

Originally posted by Snorman
So nobody really thinks I just need a taller tire?
S.

I only have one 11-second pass, but here's my .02....

No, you don't need a taller tire, but a taller tire would make it easier to launch and not run out of gear at the end. Certainly at that MPH w/ a 26" tire you're close to max RPM by the end of the 1/4, but you should be able to run an 11 easily with that MPH and a 26" tire. I couldn't get my 275/60 DRs to hook (28" tall) so I ran 26x10 M&H slicks Sunday. Guess what? My first 11-second pass. 11.938, but still an "11". And it was at only 111.79 MPH. You can do it, you just need to hook up.

For what it's worth, with my setup I ran the *exact* same MPH with my 26" tires as I did with my 28" tires. I still think I'm off a few MPH, but switching to a 26" tire from the 28" didn't affect my MPH. The only reason I squeezed out an 11 is because my 26" tire is a real slick. My 28" DRs are shot and I'm not sure what to replace them with. Not radials again, though. Prolly some DOT slicks.

I'd think, though, that given the MPH - even with your 60' time - that you'd be high 11s. You sure you're not running out of gas at the end?

Jim

 

[salvageV6]

Hoosier makes 27" Quick Time Pros if you want to split the difference.

 

[99Formula]

Are you dead set on doing it on DOT's? Borrow a set of slicks and you're there. Also, are you running at least a passenger side airbag?

Peter

 

[turbojimmy]

Originally posted by salvageV6
Hoosier makes 27" Quick Time Pros if you want to split the difference.

What size do you think I'd be able to get away with on 8" Draglites with 3.5" BS? I have 26" M&H slicks with a 10" tread but I'm not sure what size they actually are. They fit okay (though I'm not sure if they'd fit okay if they were 27" tall). After looking at the Hoosiers I'm not sure what size I'd need. Their 27x11.5" tire has a 10" tread width while their 27x10.5 has a 9.0" tread.

Any suggestions?

Thanks,
Jim