LS1GTO.com Forums banner

41 - 57 of 57 Posts

·
Worthless reject member
Joined
·
40,165 Posts
just have to slip the clutch, and don't run 30 psi on the street. run like, 20-24.

at the track, heat them up good. they will stick if the track is prepped well. you will be surprised how high you have to launch it for it not to bog down. Run 18 psi at the track.
 

·
GR-RRR!
Joined
·
5,511 Posts
Discussion Starter #42
Yeah, just give me a warm Summer-like day so I can try it again before I go buying a bunch of stuff. But when I was at the track a couple of years ago, dropping the tire pressures did absolutely nothing. First went down to 24, then down to 16. If anything it got worse. 60fts suuuuuucked. But it was like 100 degrees out (not joking) so power was down, launch box was slippery. And yes, I drove around the water box.
 

·
Worthless reject member
Joined
·
40,165 Posts
running lower pressure works with a drag radial. i mean, to an extent. you want to run the highest pressure you can while still hooking, otherwise you lose mph for no reason. drag radials generally have softer sidewalls than regular radial tires.

MT recommends 14-18 psi on their drag radials, iirc.
 

·
Registered
Joined
·
278 Posts
If it's for competition acceleration only then get a MT ET-R. I had SS's on stock wheels and they did well. I'm going to the R's next.
Mt's do run wide so you will likely need to roll fenders. You could rock the m&h 245/45/17 and be fine if you dont wanna go up to a 275.
 

·
Registered
Joined
·
1,913 Posts
Well I’ve yet to spin the nt05r’s at the track. They are much much better than 555r’s. I hear mixed things about the nitto’s and mickeys. Most people say the mickeys are superior and then some people say they nittos worked better for them. I haven’t tried the Mickey’s yet so I can’t say. I’ve got one brand new one I picked up from a buddy who destroyed the other one is a very short distance (got cut) so I need to grab another one. Wasn’t really worried about it till I wear out my nittos. I pulled a 1.7 on mine but I didn’t have enough track time to get it lower. I think a 1.5-1.6 is doable with practice. You’ll definitely have to find the sweet spot on a standard of slipping the clutch quickly.
 

·
2006GTO M6 dd-drag-roadcourse
Joined
·
1,505 Posts
I will say the NT-05R’s are tuff at the track. They want to dead hook. I usually leave at a high rpm so it spins a little then goes. But its not spinning and propelling the car like a bias ply or slick would. If the tire dead hooks a too low of an rpm it will just bog (being around stock power and stock gear ratio). The one time i got it to dead hook leaving at high rpm it twisted and snapped my passenger side innerstub instantly.

If you end up hunting times at the track go with the mickey ET Street R, or Hoosier Quick time pro. It’s easier on the drive train being a stick car. Essentially pop the clutch at 6K and let them spin and propel you out of the hole. And You can still drive on the street. Just dont do a bunch of high way miles as they are not steel belted. (275/40/17)

If you are looking for a tire that you can run on street that has max effort while ripping it up on the back roads and still has decent tire life and is steel belted for extended highway usethen go with the NT-05R or ET Street SS. The ET Street SS will need a little more heat in them to compared to the NT-05R for the same level of traction. And alternatively the ET Street SS will have a little more traction overall if fully heated up (with burnout). (275/40/17)

If you do a lot of highway driving and want something still does good in the wet/rain and is not a drag radial, look into the firestone Firehawk Indy 500. I’m telling you they are a bad ass tire. I’ve tried many different types of tires over the years looking for max traction but also turning and stopping ability. These fit the bill and wont break the bank. (245/45/17)
 
  • Like
Reactions: Kfxguy

·
Worthless reject member
Joined
·
40,165 Posts
MT ET street R bias, you mean? they make a street R bias and a street R radial, iirc.

and the ET street SS is very similar to the old ET street radials, just with a different tread pattern. i had called mickey thompson one time and asked, they said the compound and the "carcass" was effectively the same. i think it was just a rename with a few changes to the tread siping to differentiate the old product form the new, and to differentiate it from the ET street PRO.
 

·
GR-RRR!
Joined
·
5,511 Posts
Discussion Starter #49 (Edited)
Well, unexpectedly had a warmer day today and couldn't improve on my times, but I didn't try any lower pressures in my street tires. I think some drag radials are going to be the answer. Just not sure I care to spend the cash right now. Through today's experiments I did determine that raising my shift points to 7k or close to it slowed me down by 3-4 tenths. Going back to a 6500 shift point got me right back were I had been the other day, about 13.1. I had to shut down one run because I saw a large black pickup with something printed on the sides at an intersection ahead of me. Good thing, it was a State Patrol truck. Not sure how he didn't at least hear what I was doing, but he turned and went the other way.

BUT, earlier in the day I was running an errand with my brother on a major 2-lane and wanted to show off the new updated GTO. I passed one guy and as I got around there was another guy a ways ahead and the road was clear so I kept going. When I shifted into fifth I was just passing the second guy (started in third). I kept rolling a little ways past the second guy. I heard the shift light hit redline in fourth which is why I went to fifth, wasn't looking down since I was watching for traffic down the road and to the sides. When I let off in fifth we were rolling at 140. I had NO idea we were going that fast. Fastest I've ever gone before was 127 and that was in a different car. It was still pulling in fifth and ran like a champ. Previous fastest I'd gone in the GTO was 120.

I am VERY happy with the recent mods. This all happened in Mexico of course.
 

·
Worthless reject member
Joined
·
40,165 Posts
Well, unexpectedly had a warmer day today and couldn't improve on my times, but I didn't try any lower pressures in my street tires. I think some drag radials are going to be the answer. Just not sure I care to spend the cash right now. Through today's experiments I did determine that raising my shift points to 7k or close to it slowed me down by 3-4 tenths. Going back to a 6500 shift point got me right back were I had been the other day, about 13.1.
that's pretty interesting. does the software log shift times?

that makes me wonder if torque really does drop off severely enough with the stock cam to warrant wanting to shift at 6500. Also wondering about valve control. hmmmn. I know you have updated springs with your roller rockers now but playing it safe us always a good thing. I had read on ls1tech.com that the LS2 cam had issues with valve float at higher RPM's, i guess because of the lobe shape design. Supposedly, even though the specs are close to the early LS6 cam, the lobe ramps are different. Just hearsay though.

something i have always wondered is how the synchros and clutch do at 6200-6500 vs 6900-7000. I've noticed myself with the stock shifter and LS7 clutch my shifts seemed slower at higher rpm than if i just banged them at the stock redline. could just be me and being nervous or if the clutch and synchros had a harder time. I don't think i've tried shiting at close to 7000 with the S1 and the LT1-S yet.
 

·
GR-RRR!
Joined
·
5,511 Posts
Discussion Starter #51 (Edited)
Shifting was fine either way. I didn't feel any valve float but that would be more obvious on a dyno chart. But it seems whatever the case, there is no need or reason to take the revs that high. It is much the same on my L79, it can certainly go to 7k, but going beyond the 5800 redline is just making more noise and I've got the timeslips to prove it.

The Gtech graphs both the speed and time, you can certainly see the shift points. The speed graph is probably the best. The RPM graphs aren't very useful as the Gtech doesn't always read RPMs accurately.
501472



However, the G-force graph is good at showing acceleration and traction (or the lack thereof). This chart does show that my clutch is working well.

501473


But if you mean shift times as it at what RPM, like I said, the Gtech doesn't always log RPMs well. You can calibrate it one day and it is off the next. I measures RPMs better on an older car with far fewer electronics in the car and a single coil. It reads RPMs through the electrical signal coming from the cigarette lighter (where it gets its power) so it can be kind of all across the board on a car with lots of electronics. Perhaps cars with multiple coils is harder to read too, I don't know. It has the same problem in my Honda which also has multiple coils. It does a better job on my old stuff and worked pretty well on my old '93 Prelude which had just one coil and a mechanical distributor.

As far as RPM shift points I have to work from memory. I also have my shift light set at a specific RPM so I know if I've hit it already or not even if I'm not looking directly at the tach. In a real serious run I try to shift just before the shift light goes off because I will be at the RPM by the time I get the shifting started.
 

·
GR-RRR!
Joined
·
5,511 Posts
Discussion Starter #52
By contrast you can see the effects of higher RPM shifts here. The black line is the 13.0 run and the red line is the 13.4 run. You can see the sizeable difference in trap speed too. Ignore the actual trap speed numbers (they tend to be a little high) but just notice the difference, over 5 MPH difference. Even the 60ft on the 13.4 run was slightly better, but it didn't help due to the higher shift points. The 13.0 run used 6500 shift points, the 13.4 run used 7000.
501474
 

·
Registered
2004 M6 PMB
Joined
·
305 Posts
I thought about getting this setup, but no plans to take the GTO to the strip.
Sounds like it should help to not shock the tires and improve consistency.
 

·
Registered
Joined
·
1,994 Posts
Decrease your times by following these simple steps.
  1. Get rid of your 5 year old tires. DUHHHHH!!!!!!! Air them up appropriately
  2. Align the rear suspension correctly. Toe = 0, Camber (0 to .5). No reason for your car to be set up with negative camber! (Buy eccentric bolts)
  3. Increase anti squat % by raising the whole car or just rear suspension. This will increase due to the rear trailing arm design (helps 0 - 60') a lot.
  4. Increase your CG "ride height" by raising the car as much as you are comfortable (helps maximize rear load when the car reaches steady state around the 60' to the end)
  5. Increase those rear spring rates. Camber gain is your enemy and drag strips dont have bumps. Just make sure you adjust dampers appropriately to the new spring rate
  6. Rev as high as possible. The LS torque does not drop off that much. So the force available in the next gear is always less than the current. Do not rev past where your car was tuned.
  7. Get some scales and balance out those rear tire weights by adjusting cross
  8. Open up that tuning software and make sure the engine is working correctly with the DA, temp, and humidity. Big swings here if not calibrated right
  9. Minimize compliance anywhere there is a bushing. Anything absorbed here is wasted energy and will effect your alignment ( Control arm bushings, diff bushing, engine mount, trans mount, subframe mounts
Alot of work there and thats just the start. However this will make a big difference
 
41 - 57 of 57 Posts
Top