Something to think about.I scan my car alot.I use 92 octane fuel.My car is always in the low octane tables.My buddy's 99 LS1 WS6 annivesary t.a. does not have this problem nor does my other f-body friend.
At the track,i used 92 octane,did not hear knock,but the timing was 21* across the RPMs,the run was 13.8 @ 101. (auto 3:15s-unprepped track)

After pulling fuses 16 and 23 to reset the PCM,i added a can of 104 octane boost.20 minutes later ran 13.3 @ 106 five times in a row,i think one was a 13.4...28* timing across the RPMs.Stays like this until i need to refuel,then if i don't add octane,back to the low tables,i just live with it and reset the PCM and use octane at the track.Alot of c5s do this,most owners don't even notice.If you race a LS1 f-body in the low tables,you stand a good chance of losing,i never lost to one in the high tables.


One thing that made me spit my coffee on my key pad,was launching at 3700rpms,if you try that on our track,you'll sit right at the line and spin like mad.Off idle or nothing on this track,unless you pay to join the pro-gas assoc,then pay the entry fee for a certain event,then they prep the track.I can only dream of a nice track....and take some of this humidity away..midnight and it's still 70% + humidity,we can't race during the day.

 

I had my car dyno tuned, and I'm pretty sure that he set the low octane table to be identical to the high octane table.

 

Here's what I have learned with C5s + drag racing...

Auto:
Drag radials are fine, ET streets are better
3.90s are awesome
3800+ Stalls are not too big for the street
Hardened output shafts are a good idea but not necessary


6 Speed:
Drag Radials are your enemy(break too many parts)
ET streets are the hot ticket
Hardened output shafts are required
When you think your launching too high RPM add more RPM
Stock FE1 suspension kicks aruse
Z06 tranny gearing is better for 60'
Ram dual compound clutch is an awesome clutch
Ram 6 puck holds it all but is tough to drive smoothly
Aluminum flywheel is a great addition

Phil

 

I launch the car the same way for nitrous and all motor passes:
2nd gear burnout, 6800-7000 and drop the hammer, My best 60s are in the high 1.4x for both nitrous and n/a passes.

 

This makes zero sense. How could you break more parts with drag radials than you would with the much stickier ET Streets??

 

Do they make ET streets in 18"?

 

ET Streets wrinkle creating a rubber band effect. This makes for much less shock to the drivetrain when launching. Most people that break output or half shafts, do it on street tires or DR's.

My shafts are all stock and I launch at 6800 rpm's on ET streets. I've never broken anything at the track.

 

I still don't buy it. You get much better 60fts with ET Streets or slicks, and believe me, even with the wrinkle effect your car has a lot more shock on it when you launch at high rpms on slicks/ET Streets than you can ever put on it launching much lower with DRs or street tires.

 

The BFG drag radials are a very soft compound just like the MT ET streets. The drag radials being a normal radial tire that has almost 0 flex to a very very soft racing tire. The rubber band effect makes a world of difference. Since I have switched over to ET streets, I have cut faster, more consistent 60's than the drag radials. I have broken more parts that you can imagine on the BFG drag radials. Take my 2 years of experience or not, its up to you. I can guarantee you if you run drag radials and drag race your gonna be sorry in the long run. Been there done that.

 

We went racing friday and with the 26 x 11 ET streets we cut a new personal best of 1.41 60' and 6.41 @ 108 1/8. I am launching 6k + 150 shot right out of the hole. Try that on drag radials.

 

"This makes zero sense. How could you break more parts with drag radials than you would with the much stickier ET Streets??"

One word....wheelhop. I've never busted an axle or rearend on ET Streets or slicks. I can't say that I've been as fortunate on DRs (I'm talking F-bodys here, btw, but the same should be true here.) I can attest that DRs are notorious for causing some pretty VIOLENT wheelhop on a great hooking track (especially violent when we're talking 1.5 60 fts and better.) This isn't the case with ETs or slicks. Those wrinkle walls do a good job of cushioning the initial hit and also of preventing wheelhop (ya gotta spin to hop you know.)

 

I never thought about the wheelhop aspect of it, good point Colonel, I stand corrected.

 

what PSI is best to run the ET streets at to prevent breaking parts? I just picked up a set to use at the track. Being a former F-body owner ('00 WS6) I'm not too confident in launching above 3000 rpm! Someone reassure me My C5 has 3.90's, 6 speed, cam, bolt-ons, etc...

 

I run 12psi 75% of the time. It really depends on temps, track conditions, overcast, ect. We start at 12psi and go from there, mostly we launch 6000-6500 on the spray and slightly higher off.

 

That is a bad *** car. Nice runs...

 

No one ever did answer the question of whether they make ET's in 18" sizes or not, unless I missed it. All other tech info is excellent. I have also been into drag racing a long time. However, not 2 years worth of nothing but a C5. This mans experience shouldn't be questioned. I myself have a 3200 stall Yank and stock runflats. What traction!! NOT!!! I am very interested in the answer to the 18" question. Thanks.

 

I have searched the MT site for the 18" and only see a 17". So I am going to say that they do not make an 18" Yet. To solve this I am looking for some Chrome Wagon wheels to mount the 17" ET streets to and swap rims when it is track time.

 

I have been to the track many times and with the Eagle f1 runflats I pulled a 1.94 sixty foot and a best et at 12.73 at 114. No wheel hop. Then just by switching Drag radials I ran a new best of 1.82 60 foot and dropped 3 tenths to run a 12.40 at 112 and average 12.40 -12.50s all day long. Again never had wheel hop. I launch the car at 4000 rpms regulary with the tire pressure dropped around 14.

I think I might take some of the regular track ****** who go all the time advice and see whats the magic in the ET Drags.

 

The problem you have with larger tire diameters is that you NEED sidewall. If you keep making them bigger AND keep the sidewall, then they aint gonna fit in the wheel well.