Better 60 foots?

kjhansen

Member
Joined
May 26, 2001
Howdy! My TR has run 113.33-114 mph in the quarter but the best time I've gotten is 12.34, and my best 60 foot is 1.83 on MT E/T streets. I've heard about people getting 1.5 and 1.7 60 foot times on these tires but my car won't do it. It's got the StageRight Transbrake, so I can build any amount of boost I want, but anything over 10psi (E/Ts heated good, about 12-13 pounds in the tires), and I get tire spin. The car has coil spring air bags (I've tried pressures from 15 to 7 on the right--passenger side, stay at 5 on the left), a 3 1/2" pinion snubber, and boxed lower control arms.

Other mods include 8" K&N dropped behind the front bumper, Cheetah Stage III turbo, big neck intercooler, 009 injectors with Jay Carter's 108 octane chip, 160 degree thermostat, high flow radiator, RJC power plate, alcohol injection, TH 3" downpipe, test pipe with cutout, Walbro fuel pump with hot-wire, TC lockup switch, high speed fan switch, adjustable FPR, Turbolink with boost sensor, new valve springs, repaired driver's side header, and I'm running 24psi boost with 116 octane at the track.

Keith:confused:
 
60 futz??

Several items come to mind reading this post.
1. Lose the snubber! All that does is bind up the suspension and not allow it to work as designed. It can also cause a real hard hit on the tires and cause the suspension to unload after launch, allowing wheelspin. Snubbers were used on leaf spring cars in the 60's... NOT on 4 link cars...
2. Unhook or remove the ft sway bar, if not already done.
3. Get a GOOD set of shocks for the rear.
4. Try more air in the tires. Our testing w/ MT shows that tire at 15-16 psi to work best.

Questions:
1. Why the alky and race gas too? At what boost is the alky coming on?? Could be the alky is "putting the fire out" if it comes on too soon after launch.[Thus the engine goes fat] No reason you can't try a launch with the alky off w/ 116 gas and 24psi boost.
2. What are the scan tool readings??
3. Do the tires spin after launch, like at 50', or before??
A video is helpful here.
4. Are the upper control arms boxed w/ good bushings?
5. What is the pinion angle ?
6. Are the seat and ft frame braces in place?
7. What condition are the body mounts in??
These are items that affect the ability of the suspension to work properly.
8. What condition is the limited slip diff in??
Looking at the "magic chart", I see the following performance, considering the MPH you are reporting. These are numbers that the car should produce if tuned and launching properly.
Beginning at the 1/4mph at 113:
113/11.70ET, 660'/7.25, 330'/4.60, 60'/1.57
As you indicate, the short times are off by some .2 to .3. Getting the short times to the 1.6 area will cut about .40 off the et and put you in the high 11 range...[You may have to go to slicks to do the 1.5 short time]

Lastly, I'd look at that 8" air cleaner.. may NOT be enuf air to support even better performance....
Look at the suspension items mentioned above and go from there. Let us know what you find...;)
 
Keith,

The thing with that turbo is that it's exhaust housing is really big. I know because I ran that turbo before my TE-44. A turbonetics .63 housing (what you have on the cheetah) is equivalent to a garrett .85 housing. Therefore, you won't make any torque down low where your ET is made, but you will make high MPH due to the big exhaust housing. The ONLY way to get a nice 60' with that Turbo is to lanch at 15psi + and try to get the car to hook, or get a garrett .63 exhaust housing (off a stock GN turbo) and have it machined to fit a stage III exhaust wheel and put it on the cheetah. Thats what I was going to do before I decided to go with the 44, which I do have a stock .63 housing on.

I ran a best ET of 12.94 @ 108 with a horrible 1.94 on ET drags lanching the car at 8-9psi with that turbo (Cheetah) and almost the same exact combo as yours. I went to a 44 with a .63 housing and droped a full second. 60's are now 1.67-1.70.

If hooking up is a problem, try removing the front sway if you have not done so yet. It did the trick on my car.
HTH
:cool:
 
keith, man i had the same combo except for i had a frontmount and an ART CARR 9". i left on 0 psi boost, on MT drags 28x9 with 14psi in them. 24 boost on 93 octane and alky. i had the swaybar on and the drag shocks set on 70/30.
1.51 60ft.
7.13 1/8th mile
96 mph
11.38 1/4 mile
113 1/4 mph

well as you can see the 1/4 mph was way off. i had to get out of the gas cause my alky wire got pulled apart due a broken motor mount which caused a blown head gasket. on later inspection i had a broken turbine wheel blade. it was a hell mary pass. but it was worth it. good luck. jeremy
 
Re: 60 futz??

Originally posted by Chuck Leeper
Several items come to mind reading this post.
1. Lose the snubber! All that does is bind up the suspension and not allow it to work as designed. It can also cause a real hard hit on the tires and cause the suspension to unload after launch, allowing wheelspin. Snubbers were used on leaf spring cars in the 60's... NOT on 4 link cars...
2. Unhook or remove the ft sway bar, if not already done.
3. Get a GOOD set of shocks for the rear.
4. Try more air in the tires. Our testing w/ MT shows that tire at 15-16 psi to work best.

Questions:
1. Why the alky and race gas too? At what boost is the alky coming on?? Could be the alky is "putting the fire out" if it comes on too soon after launch.[Thus the engine goes fat] No reason you can't try a launch with the alky off w/ 116 gas and 24psi boost.
2. What are the scan tool readings??
3. Do the tires spin after launch, like at 50', or before??
A video is helpful here.
4. Are the upper control arms boxed w/ good bushings?
5. What is the pinion angle ?
6. Are the seat and ft frame braces in place?
7. What condition are the body mounts in??
These are items that affect the ability of the suspension to work properly.
8. What condition is the limited slip diff in??
Looking at the "magic chart", I see the following performance, considering the MPH you are reporting. These are numbers that the car should produce if tuned and launching properly.
Beginning at the 1/4mph at 113:
113/11.70ET, 660'/7.25, 330'/4.60, 60'/1.57
As you indicate, the short times are off by some .2 to .3. Getting the short times to the 1.6 area will cut about .40 off the et and put you in the high 11 range...[You may have to go to slicks to do the 1.5 short time]

Lastly, I'd look at that 8" air cleaner.. may NOT be enuf air to support even better performance....
Look at the suspension items mentioned above and go from there. Let us know what you find...;)
=============================================
After reading your message here's my thoughts and some answers to your questions:
1. The snubber is easy to remove, but does the 4-link keep the differential/driveshaft link from over-rotating and going past "instant center"?
2. I don't remember if the sway bar was off or on (last run at the track was over 2 years ago in Texas). In any case, my 60-foots have been about the same with it on as with it off.
3. When you say good shocks for the rear, is that as in "soft" or firm? I do have coil spring air bags, so am not sure what difference shocks will make.
4. OK.

Your questions:
1. Alky and race gas: Because I was getting a lot of knock even with race gas. I've experimented with various jet sizes. Bigger jets make it go flat at speed. A small jet works good with high octane.
2. By scan tool readings, do you mean O2mv's? I'll have to look this stuff up. I have it somewhere.....
3. Tires spin on launch (if over 10-11psi boost) and continue (chirping) for about 100 feet or so (???)
4. Upper control arms are NOT boxed and bushings are original (148K)
5. I have no idea what the pinion angle is.
6. Do you mean the aftermarket seat braces that fit in the trunk? Front braces under the hood? The body is stock with no aftermarket braces. I've gotten wrinkles in the roof over the "opera windows"
7. I have never looked at the body mounts.
8. The limited slip will let the right rear spin by itself in the right conditions.... It's actually not stock to the TR. I bought a used '79 Camaro posi and had it installed, so it was old already.

Up here at 6100 feet I'm running G-Tech readings of 12.5-12.6 at 114mph. Still good mph, but the G-Tech gives higher mph than the clocks at a track. On the other hand, I've added the TH downpipe and the RJC Powerplate since getting here so I don't think I've lost as much as a naturally aspirated car would, but it's still slower than at 700 feet in San Antonio.

Keith
 
You should not be getting knock on 116. Something is wrong. Either the knock is false or you have too much boost or timing.

With alky on with race gas it is probably pig rich which will kill 60' times
 
Chuck,
You asked what the scan tool readings were. It took a little while to dig back in the archives but this is what I found (abbreviated):

Fr. TPS/O2mV/Air/ret/boost
1. 4.54/789/249/.9/18
2: 4.74/ 847/ 245/ 0/ 20
3: 4.76/ 785/ 238/(3rd) 2.6/ 22
4: 4.8/ 808/ 235/ 2.4/ 23
5: 4.8/ 785/ 238/ 7.1/ 23.5
6: 4.8/ 773/ 238/ 8.2/ 23
7: 4.82/ 773/ 238/ 3.3/ 22

Lots of knock retard, relatively speaking, even with 116 and a little alcohol. I also have an engine tie-down.
This run was 12.379@113.33 with a 1.829 60 ft off of that 18psi boost launch.
Keith
 
Reply to??

Keith wrote:
After reading your message here's my thoughts and some answers to your questions:
1. The snubber is easy to remove, but does the 4-link keep the differential/driveshaft link from over-rotating and going past "instant center"?
IF the suspension bushings and arms are of sufficient strength, they will hold the diff in the location it is set to, or VERY close. The IC on these cars is not right to begin with and requires substancial mods to correct. However, working within the stock or near stock parameters can result in acceptable short times.
2. I don't remember if the sway bar was off or on (last run at the track was over 2 years ago in Texas). In any case, my 60-foots have been about the same with it on as with it off.
This can be a result of other problems.
3. When you say good shocks for the rear, is that as in "soft" or firm? I do have coil spring air bags, so am not sure what difference shocks will make.
Air bags are a "crutch" alot of us use to help correct other problems. Air bags are not a good tuning tool, other than to correct for tire loading, or lack of. Springs support the wt of the car, the shocks are a tuning tool that is used to control how the tires react to shock loading, IE; "hit". They DO NOT contribute to suport of wt.
4. OK.

Your questions:
1. Alky and race gas: Because I was getting a lot of knock even with race gas. I've experimented with various jet sizes. Bigger jets make it go flat at speed. A small jet works good with high octane.
WHOA!!! Knok w/ 116 tells me something serious is wrong w/ this combo. My suggestion is to find it before you part company w/ the head gaskets or the crank! I'd NOT use alky to cover that problem up..
2. By scan tool readings, do you mean O2mv's? I'll have to look this stuff up. I have it somewhere.....
3. Tires spin on launch (if over 10-11psi boost) and continue (chirping) for about 100 feet or so (???)
Lack of wt transfer can cause this, tire bounce due to too much air in the bags,or bad shocks. Tires on rims that are too narrow can also cause this.
4. Upper control arms are NOT boxed and bushings are original (148K)
This needs to be addressed. Suggest adjustables, w/ pinion angle in the 3-4* area.
5. I have no idea what the pinion angle is.
Check it w/ a protractor. Sears sells them inexpensive.
6. Do you mean the aftermarket seat braces that fit in the trunk? Front braces under the hood? The body is stock with no aftermarket braces. I've gotten wrinkles in the roof over the "opera windows"
Those wrinkles are due to body flex. If they continue to be "hit on", you can expect cracks at the A and B pillar corners.
7. I have never looked at the body mounts.
I'd do the body mounts w/ the poly kit from either ENERGY, or PST.. A good 1 day project and it'll really tighten the car up!!
Get the ft and rear braces in also.. getting the frame and body as rigid as possible is MANDATORY for repeatable performances.
8. The limited slip will let the right rear spin by itself in the right conditions.... It's actually not stock to the TR. I bought a used '79 Camaro posi and had it installed, so it was old already.
At minimum, do a rebuild.. Not much sense trying to get a peg leg to perform.

Up here at 6100 feet I'm running G-Tech readings of 12.5-12.6 at 114mph. Still good mph, but the G-Tech gives higher mph than the clocks at a track. On the other hand, I've added the TH downpipe and the RJC Powerplate since getting here so I don't think I've lost as much as a naturally aspirated car would, but it's still slower than at 700 feet in San Antonio.
It will be!

HTH, Back under my rock!

:D :D :D
 
Knok knok??

Keith wrote:
Chuck,
You asked what the scan tool readings were. It took a little while to dig back in the archives but this is what I found (abbreviated):

Fr. TPS/O2mV/Air/ret/boost
1. 4.54/789/249/.9/18
2: 4.74/ 847/ 245/ 0/ 20
3: 4.76/ 785/ 238/(3rd) 2.6/ 22
4: 4.8/ 808/ 235/ 2.4/ 23
5: 4.8/ 785/ 238/ 7.1/ 23.5
6: 4.8/ 773/ 238/ 8.2/ 23
7: 4.82/ 773/ 238/ 3.3/ 22

The chip gurus should chime in here..
My take is that the MAF readings are low, O2's are bout right, knock is unacceptable, TPS is OK.
Without seeing the car and looking at current data, it's difficult to "tune by mail"..Anyone else???
 
My guess is try someone elses chip. Your current one seem to be good down low, but once in third gear, your leaning out! (Again, due to the big exhaust housing on that turbo).

Try running more fuel up top and see what happens to your 02's and MPH. It should make your KR disappear, and that should be your biggest concern right now.

Forget about 60's, 22-23 psi of boost and 7-8* of KR don't mix!

Just my .02.
:cool:
 
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