275/40-17 ET Radials, still only a 1.9 sixty?
07-10-2006, 09:34 AM
#1
Melting Slicks
Thread Starter
275/40-17 ET Radials, still only a 1.9 sixty?
I can't get my 91 to sixty foot worth a damn. The car is basically a stock 1991 6 speed, with nitrous, a McLeod twin disk clutch, and ET street radials. On the bottle the car is making ~330 RWHP and ~450 RWTQ.
Prior to the nitrous (250 RWHP/340 RWTQ) and without the ET street radials, my best time was a 13.9 @ 101, with a 2.2 sixty. I have been as low as 1.9 on the street rubber, but 2.0-2.2 is my average. When I do manage to occasional 1.9 the ET never seems to come with it for some reason.
With nitrous, on the street rubber, I ran a 13.5 @ 107, with another 2.2 sixty. I had to activate the nitrous in second gear because a first gear activation just blew the tires off. I was expecting to pick up close to .1 for every 10 RWHP added via nitrous, so I was kinda let down when I only picked up .4, but I did pick up 6 MPH.
I thought for sure the car would go low 13's with the nitrous and ET street radials, so I bought a pair 275/40-17's and had them mounted on the stock wheels. I went to the track and made a couple passes on motor to get used to the tires. I started with 35 PSI in the radials. Anything less than a 3500 RPM clutch release resulted in the car bogging down pretty badly, giving sixty foot times in the 2.1-2.2 range. 3500+ RPM clutch releases spun the tires to the point where I tried to peddle the throttle a bit to get them to hook. This did net a bit better average 60 foot time of 2.0-2.1. I aired the ET radials down in 5 PSI increments all the way to 20 PSI with no change in 60 foot time or perceived hook. My best NA pass of the day was 14.1 @ 99, it was hot with high humidity though so I think I am pretty much on par with my previous best time of 13.9 @ 101. Again though, I was slightly dis-heartened that with the new tires I didn't manage a new best 60' time, or new best overall NA ET.
I opened the bottle, dropped the PSI to 18 and made another half a dozen passes. Launching on the juice at about 3,000 RPM's seemed to yield the best results with an average 60 of 2.0 and a single 1.9 pass. The ET was no better, the same 13.5 that I ran with street tires, and the MPH actually went down to 105 from the 107 I ran on street tires.
I was able to use the nitrous in first gear, where I wasn't on street tires, so I thought for sure I would see an ET improvement. The way it sits right now, the radials were a waste of money. I am cutting the same sixty foot times with them as I was on street tires, only it's immensely harder on the drive train. I have tried regular, non-radial ET streets on other cars and they always dead hook, even on cars making almost twice the HP I am. Maybe I should of just bought some 16 inch wheels and went with those?
I don't have a line lock, so I am only able to do a short burnout.
Any advice would be appreciated.
Prior to the nitrous (250 RWHP/340 RWTQ) and without the ET street radials, my best time was a 13.9 @ 101, with a 2.2 sixty. I have been as low as 1.9 on the street rubber, but 2.0-2.2 is my average. When I do manage to occasional 1.9 the ET never seems to come with it for some reason.
With nitrous, on the street rubber, I ran a 13.5 @ 107, with another 2.2 sixty. I had to activate the nitrous in second gear because a first gear activation just blew the tires off. I was expecting to pick up close to .1 for every 10 RWHP added via nitrous, so I was kinda let down when I only picked up .4, but I did pick up 6 MPH.
I thought for sure the car would go low 13's with the nitrous and ET street radials, so I bought a pair 275/40-17's and had them mounted on the stock wheels. I went to the track and made a couple passes on motor to get used to the tires. I started with 35 PSI in the radials. Anything less than a 3500 RPM clutch release resulted in the car bogging down pretty badly, giving sixty foot times in the 2.1-2.2 range. 3500+ RPM clutch releases spun the tires to the point where I tried to peddle the throttle a bit to get them to hook. This did net a bit better average 60 foot time of 2.0-2.1. I aired the ET radials down in 5 PSI increments all the way to 20 PSI with no change in 60 foot time or perceived hook. My best NA pass of the day was 14.1 @ 99, it was hot with high humidity though so I think I am pretty much on par with my previous best time of 13.9 @ 101. Again though, I was slightly dis-heartened that with the new tires I didn't manage a new best 60' time, or new best overall NA ET.
I opened the bottle, dropped the PSI to 18 and made another half a dozen passes. Launching on the juice at about 3,000 RPM's seemed to yield the best results with an average 60 of 2.0 and a single 1.9 pass. The ET was no better, the same 13.5 that I ran with street tires, and the MPH actually went down to 105 from the 107 I ran on street tires.
I was able to use the nitrous in first gear, where I wasn't on street tires, so I thought for sure I would see an ET improvement. The way it sits right now, the radials were a waste of money. I am cutting the same sixty foot times with them as I was on street tires, only it's immensely harder on the drive train. I have tried regular, non-radial ET streets on other cars and they always dead hook, even on cars making almost twice the HP I am. Maybe I should of just bought some 16 inch wheels and went with those?
I don't have a line lock, so I am only able to do a short burnout.
Any advice would be appreciated.
Last edited by neat; 07-10-2006 at 09:35 AM. Reason: clarity
07-10-2006, 10:41 AM
#2
Le Mans Master
Originally Posted by neat
I can't get my 91 to sixty foot worth a damn. The car is basically a stock 1991 6 speed, with nitrous, a McLeod twin disk clutch, and ET street radials. On the bottle the car is making ~330 RWHP and ~450 RWTQ.
Prior to the nitrous (250 RWHP/340 RWTQ) and without the ET street radials, my best time was a 13.9 @ 101, with a 2.2 sixty. I have been as low as 1.9 on the street rubber, but 2.0-2.2 is my average. When I do manage to occasional 1.9 the ET never seems to come with it for some reason.
With nitrous, on the street rubber, I ran a 13.5 @ 107, with another 2.2 sixty. I had to activate the nitrous in second gear because a first gear activation just blew the tires off. I was expecting to pick up close to .1 for every 10 RWHP added via nitrous, so I was kinda let down when I only picked up .4, but I did pick up 6 MPH.
I thought for sure the car would go low 13's with the nitrous and ET street radials, so I bought a pair 275/40-17's and had them mounted on the stock wheels. I went to the track and made a couple passes on motor to get used to the tires. I started with 35 PSI in the radials. Anything less than a 3500 RPM clutch release resulted in the car bogging down pretty badly, giving sixty foot times in the 2.1-2.2 range. 3500+ RPM clutch releases spun the tires to the point where I tried to peddle the throttle a bit to get them to hook. This did net a bit better average 60 foot time of 2.0-2.1. I aired the ET radials down in 5 PSI increments all the way to 20 PSI with no change in 60 foot time or perceived hook. My best NA pass of the day was 14.1 @ 99, it was hot with high humidity though so I think I am pretty much on par with my previous best time of 13.9 @ 101. Again though, I was slightly dis-heartened that with the new tires I didn't manage a new best 60' time, or new best overall NA ET.
I opened the bottle, dropped the PSI to 18 and made another half a dozen passes. Launching on the juice at about 3,000 RPM's seemed to yield the best results with an average 60 of 2.0 and a single 1.9 pass. The ET was no better, the same 13.5 that I ran with street tires, and the MPH actually went down to 105 from the 107 I ran on street tires.
I was able to use the nitrous in first gear, where I wasn't on street tires, so I thought for sure I would see an ET improvement. The way it sits right now, the radials were a waste of money. I am cutting the same sixty foot times with them as I was on street tires, only it's immensely harder on the drive train. I have tried regular, non-radial ET streets on other cars and they always dead hook, even on cars making almost twice the HP I am. Maybe I should of just bought some 16 inch wheels and went with those?
I don't have a line lock, so I am only able to do a short burnout.
Any advice would be appreciated.
Prior to the nitrous (250 RWHP/340 RWTQ) and without the ET street radials, my best time was a 13.9 @ 101, with a 2.2 sixty. I have been as low as 1.9 on the street rubber, but 2.0-2.2 is my average. When I do manage to occasional 1.9 the ET never seems to come with it for some reason.
With nitrous, on the street rubber, I ran a 13.5 @ 107, with another 2.2 sixty. I had to activate the nitrous in second gear because a first gear activation just blew the tires off. I was expecting to pick up close to .1 for every 10 RWHP added via nitrous, so I was kinda let down when I only picked up .4, but I did pick up 6 MPH.
I thought for sure the car would go low 13's with the nitrous and ET street radials, so I bought a pair 275/40-17's and had them mounted on the stock wheels. I went to the track and made a couple passes on motor to get used to the tires. I started with 35 PSI in the radials. Anything less than a 3500 RPM clutch release resulted in the car bogging down pretty badly, giving sixty foot times in the 2.1-2.2 range. 3500+ RPM clutch releases spun the tires to the point where I tried to peddle the throttle a bit to get them to hook. This did net a bit better average 60 foot time of 2.0-2.1. I aired the ET radials down in 5 PSI increments all the way to 20 PSI with no change in 60 foot time or perceived hook. My best NA pass of the day was 14.1 @ 99, it was hot with high humidity though so I think I am pretty much on par with my previous best time of 13.9 @ 101. Again though, I was slightly dis-heartened that with the new tires I didn't manage a new best 60' time, or new best overall NA ET.
I opened the bottle, dropped the PSI to 18 and made another half a dozen passes. Launching on the juice at about 3,000 RPM's seemed to yield the best results with an average 60 of 2.0 and a single 1.9 pass. The ET was no better, the same 13.5 that I ran with street tires, and the MPH actually went down to 105 from the 107 I ran on street tires.
I was able to use the nitrous in first gear, where I wasn't on street tires, so I thought for sure I would see an ET improvement. The way it sits right now, the radials were a waste of money. I am cutting the same sixty foot times with them as I was on street tires, only it's immensely harder on the drive train. I have tried regular, non-radial ET streets on other cars and they always dead hook, even on cars making almost twice the HP I am. Maybe I should of just bought some 16 inch wheels and went with those?
I don't have a line lock, so I am only able to do a short burnout.
Any advice would be appreciated.
07-10-2006, 11:01 AM
#3
Race Director
There have been posts on here from folks who have spoken with the MT compnay and they told them to do a real good burn out before their first run...every run thereafter only do a light burnout...good luck...
07-10-2006, 11:20 AM
#4
Team Owner
Originally Posted by Fuzzy Dice
There have been posts on here from folks who have spoken with the MT compnay and they told them to do a real good burn out before their first run...every run thereafter only do a light burnout...good luck...
Inflation Pressures
On the racetrack DO NOT use starting pressures below 11 psi.
Recommend pressures for:
* P295 and larger sizes: 11-14 psi
* P275 and smaller sizes: 12-16 psi
On the highway we recommend running 75% of the max psi as notes on the sidewall of the tire.
Burnouts
The tread compound used in the ET Street Radials is designed to heat quickly and does not require a heavy burnout. Continue the burnout until the engine starts to pull down. We do not recommend a dry hop after the burnout.
Chris
07-10-2006, 11:33 AM
#5
Melting Slicks
Thread Starter
Originally Posted by robz
The tires might be a bit too much for your rwhp and you can't take advantage of lowering the tire pressure so they hook properly. However you should still be able to cut some 1.6x's. I don't want you to break so be careful, but I would lower the tire pressure to 16psi and do a monster burnout. You'll have to come out hard like 5000+ but then you will increase your chances of breakage. IMO that should put you in the range you want. Again be careful, not sure if you have beefed up driveline parts.
My older TPI style engine is dead at 5,000. I don't think the engine will even free rev to 5500, lol. It seriously noses over about 4700, and my 5k, it is just out of breath, so I don't know what launching from that RPM will gain me, but I'll give it a shot.
To do a smokey burnout I would have to power brake the car. Even then I don't know that I could get the tires to smoke with out using the nitrous. I never did do a good burnout though, so maybe I'll try laying on the brake and seeing what happens.
07-10-2006, 11:46 AM
#6
Le Mans Master
Originally Posted by chaase
They don't require a big burn out.. from the website
Inflation Pressures
On the racetrack DO NOT use starting pressures below 11 psi.
Recommend pressures for:
* P295 and larger sizes: 11-14 psi
* P275 and smaller sizes: 12-16 psi
On the highway we recommend running 75% of the max psi as notes on the sidewall of the tire.
Burnouts
The tread compound used in the ET Street Radials is designed to heat quickly and does not require a heavy burnout. Continue the burnout until the engine starts to pull down. We do not recommend a dry hop after the burnout.
Chris
Inflation Pressures
On the racetrack DO NOT use starting pressures below 11 psi.
Recommend pressures for:
* P295 and larger sizes: 11-14 psi
* P275 and smaller sizes: 12-16 psi
On the highway we recommend running 75% of the max psi as notes on the sidewall of the tire.
Burnouts
The tread compound used in the ET Street Radials is designed to heat quickly and does not require a heavy burnout. Continue the burnout until the engine starts to pull down. We do not recommend a dry hop after the burnout.
Chris
07-10-2006, 12:59 PM
#7
Team Owner
Originally Posted by robz
A big burnout for diagnostic purposes won't hurt, it appears he's not getting the tires hot at all. And the psi very's so much from car to car. I believe he will be fine with 18-20psi since he has only 335rwhp. I never found the company recommendations to be very useful but they will at least get you in the ballpark.
I suggest you get a line lock to help w/burn outs.
07-10-2006, 02:12 PM
#8
Le Mans Master
When I went from street tires to DR's & from DR's to ET Streets, it took me about 4-5 trips to the track to get my launches down. You have to learn how to launch YOUR car on the new tires. Your MPH will most likely go down a bit due to the increased traction. Make sure you slip the clutch & are not dumping it. I agree with Rob that I'd raise your launch rpm's. Along with slipping or riding the clutch, this should help your 60' times.
Also find out from guys on the forum where you should be shifting your particular model & set up. Shift points will make a big difference in ET.
After gathering that info, practice & seat time, along with some patience will help you out most.
PS-If you're losing your burnout mid way, you're not feeding enough throttle during the burnout. Keep the revs HIGH!!!
Ron
Also find out from guys on the forum where you should be shifting your particular model & set up. Shift points will make a big difference in ET.
After gathering that info, practice & seat time, along with some patience will help you out most.
PS-If you're losing your burnout mid way, you're not feeding enough throttle during the burnout. Keep the revs HIGH!!!
Ron
07-10-2006, 07:03 PM
#10
Race Director
I'm running (I'm guessing, based on my times) about 320 RWHP. I'm consistently getting 60' times of 1.79-1.82 seconds on my MT ET street radials. As I heard here, I give them a good burn-out on the first run, then short ~1sec burns on subsequent runs. I'm running them at 23-25 psi. With my 2600 stall TC and 3.33 gears, I don't have the horsepower to make them spin at the line. As I see it, that's where you want to be: enough traction so you can dump the clutch and not spin.