Help! Disapointed 1/4 mile times any suggestions (bummed out

[Jpalok9]

:confusedIm wondering if anyone else out there can tell me what my car should be doing in a 1/4 mile. I had a 2005 AUTOMATIC with long tubes Vararam and a great dyno tune and a set of perelli corsa . I could go to the drag strip here in Florida get to the start line put the car in d hit the gas and run 12.4 and 117mph all day long. Getting board I start going to sebring raceway and running the 3.7 mile road course. Well with the automatic it really struggled in the conners and I was told if Im going to be serios about running road courses my automatic has to go and a 6 speed is in order. Well thats what I do I get an 05 precision red vette with Z51 package and 342 rear gears 6 spd manual. I put some flowmasters on the vararam and my favorite dyno guys tune. Now I have yet to put the long tubes on and I bought a set of 4:10 rear gears for a little more umpf at sebring. My dyno guy says I sould go to the drag strip and see what my car can do now before he does the long tubes and the gears. Good idea I head out last night to the drags. Now im thinking just like you follks on the forum that with a 6 speed manual, 342 gears and a dyno I should be running 12.6 12.7 easy. My dyno numbers are 371 hp to the rear wheels so Im figuring get this bad boy to hook uip and watch out. Well now comes my dissap[ointment. my 1st run was 13.5 at 107 okay launch was hard a little slipage and spinning tires but 13,5???? next run I try to leave littel more hole shot still hitting 13.5 make a long story short my best was 13.5 at 109 a huge cry from my 12.4 117. Does anyone else out ther have a similar car as mine and what are they running for times. Im so upset I wanna sell the car and foget about wasting the money for installing the long tubes and gears. at 13.5 IM a long way of from 12.4 I was thinking i was going to be high 11s and now this. Any feedback willl be so much appreciated as I really can bel;ive I could not break 12s Again if im going to run road courses then I guess the 6spd the way but im so mad at 13.5 I feell like giving up
Feedback please sorry for thre long post
Jim

 

[catbert]

I had a fast 05 C6 auto - 12.80 (at 1,390 ft elev) with only GHLs anf CAI. When I got my Z06, it took my a bunch of runs to beat my 05s time. You kind of have to REALLY learn how to drag race again. The throttle sweet spot is very small...too much = smoke, too little = slow. The right launch was worth a full second for me.

 

[Jpalok9]

So if I hear you correctly your 05 was running faster than your ZO6 because it to was a standard in the end what did yoiu finally run on the Zo6 what year was the Zo6 how much horse alsoI have a ton of road course experience and a fair amount of drag experience with automatics, The last time a ran 1/4 miles with a stick was 1986 in my GT mustang with 390 gears and 5 spd It ran 14.8 nothing like the vette I admit I felt very aquward launching the vette the other night. It seemed like I bogged the car 1st run I just waited for green and kind of clutched my way out I ran a 13.6 Buy the way Im running Perelli corsa that when there hot stick like glue. My automatic I could go in the box get the tires good and hot then roll up to the line punch it and it hooked up perfect no spin great launch unlike my Nittos that would break loose. The next run I sat at the light reved the cat to a steady 4000rpm and whenit turned green I just dumped the clutch and the car just kin=nda bogged and then took off real har still 13.5. 3rd time I went up let the lights start to run and I floored the car an dummped the clutch. This time I dont know what happend I either broke the tires completlyt loose as the car just skinda sat the not moving much I banged into second and same thing car still didnt really move much felt like either the tires were completely broken loose and I spun all 1st and 2nd or (I don't know if this was possible) the clutch just didnt grabbed at all and slipped the whole time which is kina like it felt as a matter at the end of the run I pulled ofer and spun my tires because I thought I blew the clutch. So I guess where Im disapointed is I feel like my car has somthing mechanically wrong with it because it ran so slow but it runs perfect and it dynoed really great as well. So if im hearing everyone correctly that launch at the begining is that costly is you screw it up and being off 1 second is normal

Jim

 

[catbert]

The 05 automatic was putting out about 350 horsepower at the rear wheels, and the absolute fastest way down the 1/4 mile was just "mashing the gas" with no torque loading before the green light. My best was a little under 12.8. I never used the water box, and traction was perfect without it. Just enough wheel spin to keep revs and HP up.

The Z06 was about 470 horsepower at the wheels, and required A LOT OF FINESSE at the starting line. You have about a 50 RPM sweet spot between bogging and smoke. Where that 50 RPM occurs depends on the car and conditions. Out in Phoenix, where I was racing it was close to 2,700 RPM, except late at night. You will have to figure it out on your car. The difference between a novice driver and experienced driver in the same car can be close to 2 seconds. A Z06 should be able to run mid-high elevens all day, depending on the track and conditions. My very first Z06 run was 12.9 at 122 mph, so you can see I wasn't a "natural."

Roadracing experience is NO help on the drag strip.

 

[Jpalok9]

This is so helpful I was really depressed about the car I put it up for sale and now I have a bunch of people who want to buy it. That sweet spot is pretty interesting. The Perelli Corsas I use for rear tires are $600 a pop they are really made for oval of road courses but because they hook up so well I also use them for the drags. You said you launched your car at 2700 rpm I can tell you I was at 4000 and dumping the clutch and the tires hooked up no spin but it just bogged the car What I notioced on my dyno results was at 4100 my car had its max torque so I figured I launch at that leve but again the bogg. So to you think that having the engine reving that high at the line was not good I should go lke 3000 and clutch it out or do you think I should go 5000 and dump the clutch so the car launches harded. Remember one time I had it like 7000 dropped the clutch and up in smoke I went.
So on youe Zo6 what times do you run now. What RPM do you leave at and do you just drop the clutch or let it out slow. Im thinking the 410 gears I bought will really help the bog situation beacuse its bigger than the 342s. Just havent installed them yet. I did change my rear end fluid today with some Royal Purple. My rearend was making some crazy noises after the other night. Someone at the track told me its normal on the vetts and they sell an additive you throw in that makes the clanking go away or use royal purple which already has it in it so I did.
Well Im going to put the long tubes on this week and redyno the car should get 378-380 hp to the rear wheels so I will go pratice. My last vette I had used the Vararam intake, long tubes and magnaflows and I was at 373 to the rear wheels. Now I have Vararam, (Fast)101mm High flow throttle body and magnaflows giving me 369 so IM hoping for a bump with the long tubes and x pipe.
Please let me know where you think I should launch what rpm that is

Thanks
Jim

 

[catbert]

Some things I learned, then I'll leave it others to give their opinions/experiences:

You WILL bust something in your drive train if you increase power with the mods and get a tune AND dump the clutch. I'm thinking clutch first if you increase traction.

You don't want to launch at peak torque until you get your XXXX together.

More power is not the answer for you right now.

My 2,700 RPM launch was with a bigger engine, more HP, and running in the desert - with a lot of stored heat in the track. You might have to launch higher.

The tires should never hook up at the line. Hook-up should occur somewhere farther than 20 feet out. You are looking for enough wheelspin to keep up in the power band, but not enough to go up in smoke - the sweet spot. Gradually increase throttle after launch. You don't want to break the tires free, even after the launch.

Practice, practice practice. It's different than running an automatic - which is why I used to beat up on C5 Z06s.

I only raced the Z until I learned how to drive it. I couldn't afford the breakage that weekly racing inflicts on high power Vettes.:L

 

[Low drag - High speed]

Sometimes a little goes a long way.

Swap out your tranny fluid for B&M TrickShift and your oil for synthetic. The oil will improve lubrication and the fluid will give you a more solid pull and shift. You may even want to invest in a B&M torque converter for a higher stall speed.

 

[Idaho Slim]

Launch Tips

I went thru the very same issues at the drag strip when changing from our LT1 to a much stronger LT4, and also even put the LT4 up for sale. Many upgrades work, but the best advice was this link on launch tips by ranger acceleration, it has made a huge difference on my launch times and reaction of the car. Summer season surgery has delayed my track return, but I know my 1/4 mile times will be greatly improved. The next best tip is a set of drag radials at the CORRECT tire pressure. I believe with these 2 items mastered, you should be very close to 12.0 imho. Good luck.


Launch Tips

 

[Jpalok9]

Thanks so much for the advice I will check it out. I have gone back and still had traction problems. I was able to get it down to a 13.2 however this car has so much more perfoemance than my last coevette. I have actually have 380 hp to rear wheels and 379 lbs trq at the rear wheels. My last car was 376 at best. I also was noticing my clutch peddle when the car got real hot was staying stuck on the floor. Well come to find out thats yet another issue with the hydralic clutch set up. My fluid was BLACK as a matter of fact I have spent the last week just driving the car 5 -10 miles and then changing the fluid again. It goes right back to black. Some threads out there say it takes a long time to get it all cleaned out so that it will run clear again. However Ive notice a much better hook up at the clutch since I started. I guess the clutch dust gets in there and causes problems as well. Have you ever looked at you clutch fluid.
Thanks and IM going sub 12 eventually LOL I also have a set of 4:10s I have yet to install.
Ls1 to Ls 4 wow what were you running at first?

Jim

 

[Idaho Slim]

Thanks and IM going sub 12 eventually LOL I also have a set of 4:10s I have yet to install.
Ls1 to Ls 4 wow what were you running at first?

Jim

LT1 to LT4 (C4's) not Ls1 / Ls4 ...... I ran 13.8's with a 3.07 geared LT1. With my 6 spd LT4 (344 rwhp) - 3.45 geared - GY drag radials @ 18 lbs, I was runnning 8.5's in the 1/8th and VERY inconsistent, now at the beginning of this season I entered our local 150' drags and with the Ranger tips, greatly improved my launchs and was looking forward to racing this summer and finally hitting the 1/4 track to hopefully get into the mid 12's with this LT4, but sadly, I severed my right Achillies tendon, had surgery and looks like I will miss the complete season

 

[upinsmoke]

The Perilli is a great tire, just not a great drag tire. I added a set of MT drag radials to my old stock wheels and picked up .5 in the1/4. It was well worth the 400 bucks. The six speed is a lot harder to master in drag racing which is why most guys run automatics. When you have a car that sees double duty there is always a compromise. The 4.10 gears will also help a lot in the 1/4. It keeps the motor in the sweet spot thru every gear change. Good luck and have fun!!!