Questions for KEVINS, went to the track on new combo

[striker_29]

Help me out here guys. I see from some of the other posts that you guys are doing some things to get some really good 60 ' times. I went to the track this weekend, and was not very pleased with the results on my new combo. My best run was a 12.5@110 and 2.014 60' times. This was on 25lbs of boost and an RA106 chip on Nittos. Now I had some slower runs, but 60' times and Mph stayed the same every run and they are obviously hurting me. So what am I doing wrong here guys? I am looking for any suggestions, I know you guys are getting some really good numbers and I have got to change some things. TIA...Mark

 

[UNGN]

Without porting the heads, your mph won't get much better if you still want to use nittos. A n/l converter and 25.6" tall tires = 110 mph. Your mph will pick up if you switch to 28" tall tires.

Is the car spinning or bogging? how much boost do you leave with? How much air in the air bag? What tire pressure and what wheels?

 

[striker_29]

Ok I was pretty much on track with my thinking then, cause I was sure thinking I need to do something to those heads. If I just port the stock heads, will that help enough? To answer your questions, the car was spinning some, but it was not terrible. I was leaving around 4~5 lbs too keep them from breaking loose. About 15 lbs in the drag radials on stock gn wheels. I do not have airbags. Thanks guys...Mark

 

[Chuck Leeper]

Poor short times

What, if anything, have you done to the suspension??
There are some very important pieces to the puzzle that need to be addressed to get the car into the 1.60 range.
1. Aftermkt or boxed stock arms w/ poly bushings.
2. Pinion angle set in the 2-4* range. [Adjustable uppers]
3. Air bags or adjustable anti-roll bar.
4. Good shocks.. IE: some good 50/50's to begin with.
5. Ft sway bar off??
6. Replace the body mounts to help tighten the chassis up??
7. Have you played w/ tire PSI?? Is 15psi the optimum??
8. Tried slicks??
9. Engine tuning.
A. Have you recorded the O2's and such at launch??
A fat motor will KILL the short times.
B. Have you tried to footbrake the car so as to not hit the tires so hard and perhaps see a better short time?
10. Does the car leave and then spin the tires after it's moving?

Answers to these items will help get the combo dialed in w/ some good short times and that will be great for the total ET improvements!!

 

[UNGN]

get a right side airbag, put 20 psi in it and put 18-20 psi in the tires.

"About 15psi" is too low for a 275/50 radial on a 7" rim.

 

[azgn]

I don't imagine you will see any 1.6 60' times on a 110 mph car under any circumstances......60' times are as much about HP as traction....no doubt you can improve from a 2.x, but anything in the 1.8's would be fine for your power level

if you want a clear picture of how power relates to 60' times, take a look at the "readers rides" section of gnttype.org....you'll see 60' times go down as speed goes up as a direct correlation (and usually by the time you are doing consistent 1.6x, traction is not the problem....power is)

 

[striker_29]

Thanks for all the replies fellas. Now on the amount of boost I was launching at, that is an estimate. I was totally watching the tree, and Ds doesnt have boost sensing,so I can't say for sure on that. I was launching by "feel" just trying to keep from frying the tires.I really dont know much at all about supensions in general, and not sure exactly whats been done on this car. I bought it several months back, but I can talk to the previous owner and find out. So I will do that, get a right side airbag and adjust tire pressure. Also gonna check into doing something to the heads. Would Kyb shocks be something to go with? Here is my timeslip if anyone wants to critique:

R/T ... .526
60' ... .2.040
330... .5.403
1/8 ... .8.170
MPH... .89.03
1/4 ... .12.594
MPH.. .110.26

Thanks...Mark

 

[turbocliff]

I'm actually wondering what 60' times guys have actually been able to pull out of the TRs with Nittos/ Drag Radials. I myself gave a few pulls on the Drag Radials, and was only able to get a 1.8, but bolt on my 28X10.5 ET Drags, and 1.55-1.59 every time. Stock rear suspension, rear end, no sway bar up front, 90/10s and front Moroso drag springs. I'm also only launching off the foot brake at about 6-8lbs. of boost as not to break axles- although I just might.

Knock on wood

 

[KEVINS]

Donald McMullin runs low 12’s @ 110mph and has gone 1.65 with BFG DR’s but he has relocated the Instant Center among other things…

As far as me I use HIGH boost launches (15psi) to get 1.60's but it requires slicks.

A good tight suspension is a good starting place then a GOOD engine tune to make the most power at the lower rpms...

The biggest thing is going to be slicks so you can launch with some boost. If you don't want slicks then fine tuning the front end rise and getting the rear end to maintain traction are your best bet which is going to require some videos so you can see exactly where and when it's spinning..

ks

 

[azgn]

Kevins, I know Donald and have gone racing with him a few times...I don't recall any 60' times like that on DR's (but I wasn't taking notes).....he just recently got some slicks and was cussing them the last time I saw him, but I'm sure he'll get 'em dialed in

these cars will 60'better than most for the power available because of the basic 4-link suspension, but brute power works well if the suspension is tight....I can and have run 1.4x but with high boost t-brake launches & slicks.....power is king!

 

[KEVINS]

I took his #'s from his sig, but I guess his sig lists his "best" times so maybe those were not good average ET's to use. I don't know what an average run is for him.
I just remember that I was VERY impressed with his 1.65 on DR's..

Sorry for any confusion..

ks

 

[V6POWER]

I see that O2 was mentioned on launch. What is a good O2 number to see on launch? Mine are in the 870 area (rich). Thanks.

 

[KEVINS]

Something that may help is your technique.. Since you're using DR's make sure that you are flashing the converter and not preloading it. If you flash the converter this will help get the suspension working and get some weight transfered quickly. I have no idea how that turbo and converter works by flashing it though so it may not work with your combo...

ks

 

[azgn]

It is possible to get good short times on DR's and I don't doubt Donald has a 1.6x on his....one of the GN guys here also has an Olds 442 with a Mondello BB and he gets high 1.6's on DR's by leaving off idle and runs 12.0's I think it requires a little more technique (check with UNGN) on a GN!

02's at launch (really at spoolup) should be as lean as possible....this has to be handled in the chip....the MaxEffort does this....my 02's at spoolup are in the 2-300's...this heats up the exhaust and spins the turbo faster.......I imagine the Trans+ will do this also....otherwise you need to work with whoever did your chip....it really requires another fuel curve (a FAST system will handle this just fine too!)

 

[c&cgn]

Originally posted by striker_29
Thanks for all the replies fellas. Now on the amount of boost I was launching at, that is an estimate. I was totally watching the tree, and Ds doesnt have boost sensing,so I can't say for sure on that. I was launching by "feel" just trying to keep from frying the tires.I really dont know much at all about supensions in general, and not sure exactly whats been done on this car. I bought it several months back, but I can talk to the previous owner and find out. So I will do that, get a right side airbag and adjust tire pressure. Also gonna check into doing something to the heads. Would Kyb shocks be something to go with? Here is my timeslip if anyone wants to critique:

R/T ... .526
60' ... .2.040
330... .5.403
1/8 ... .8.170
MPH... .89.03
1/4 ... .12.594
MPH.. .110.26

Thanks...Mark

Tough to asses your problem if you don't know what you have or what you are launching with. Slicks really make all of the difference in the world, but if you decide that you have to stick with teh DR's, listen to some of the suggestions the guys mentioned here.

FWIW here is my setup:
KYB shocks
Moog stock replacement shocks (don't know what #'s though)
Bone stock untouched upper CA's
Boxed stock LCA's with rubber 1LE bushings
ATR rear swaybar
air bags on both sides: best psi has been 9psi DS and 22psi PS with slicks and 12DS and 28PS with DR's

My best 60' to date is a 1.55 on 28x10x16" Hoosier's. I also had a best of 1.59 on the 26" MT and a best of 1.72 on the 275/50 Nitto's

Hope that helps a little.

 

[Chuck Leeper]

870's on launch??

Look quik, I see that a leaner AFR will allow the car to spool much quicker and think something in the 76-780 range might be faster.
worked on a TTA that was fat and would build ZERO boost on the brakes. I took the AFR up and got the O2's to the above mentioned area and 10psi was a snap!!

 

[V6POWER]

Thanks Chuck. I need to send this chip back to Bob Bailey and have some fuel taken out of bottom end.

 

[striker_29]

Ok so I should be happy with some 1.8's or so on the Nittos with a little suspension tweaking. My 02's are around 830 at launch so I may get with Red and go down just a bit there. And on the MPH problem, nobody has really said anything about porting the stock heads. How much will that help on the mph? Are there any good "tricks" for the stock heads? I am thinking about locking the converter, but not sure on that one yet. Thanks for the input here, this is a very good discussion. Looking at my timeslip keeps pissing me off, things have got to change a bit. At least my reaction time was decent I'd rather make more top end power and tweak the suspension than go with slicks right now. Thanks...Mark

 

[azgn]

just keep this in mind.......the cheapest improvement in your 1/4 mile times is in the first 60'...... .1 there = .15-.2 on the other end ( and you don't have to take your heads off.....just get some tires & practice)

you will never realize your car's potential without slicks....some don't care, and that's ok too, but I bet I win the race if I have slicks and you don't!!!!

BTW, they are cheap too....I have a set of 28X9 ET Drags with 150 passes on them that are barely half worn...try that on drag radials!

 

[blackshoebox]

Originally posted by striker_29
Ok so I should be happy with some 1.8's or so on the Nittos with a little suspension tweaking. My 02's are around 830 at launch so I may get with Red and go down just a bit there. And on the MPH problem, nobody has really said anything about porting the stock heads. How much will that help on the mph? Are there any good "tricks" for the stock heads? I am thinking about locking the converter, but not sure on that one yet. Thanks for the input here, this is a very good discussion. Looking at my timeslip keeps pissing me off, things have got to change a bit. At least my reaction time was decent I'd rather make more top end power and tweak the suspension than go with slicks right now. Thanks...Mark

A few things I noticed.

1. You are running the 106 chip, which is a low timing/high boost chip. I run 24-25 psi with a 108 chip which has way higher timing then a 106 chip. What are your o2's on the big end?? I know of a few guys that run that chip, and they typically run 27-32 psi. If you wanna run 24-25 boost, maybe try a higher timing chip, other wise crank it up!
2. If you do a good port job on the stock heads. 3-4 mph is a realistic gain with bigger valves.
3. Locking up the converter was worth 25 hsp and 80 foot pounds of torque on the dyno with my car which equals roughly 2 tenths and another two mph.
4. Lose the Nitto's immediately. Those tires suck. If you like drag radials, get a set of BFG's. 275/60/15's. Other wise get a pair of et drags(slicks).

Whats your tps set @ idle and what are you getting on the big end? Iac @ Idle?