Took the Z out to the track today.

1st let me tell you couple things about the car

1. I bought the car and a few days later I realized the intake filter was destroyed. It was a foam one from Vararam and god knows how long the car ran without a filter. the foam was gone so it was sucked into the engine...

2. Both the driver and passenger side headers got banged up pretty bad from a ladder that went under the car. the passenger side is real bad and had a rip in it that I had to get welded. I wish I had a pic to show, but I think it's robbing alot of power.

3. Due to the filter being missing, and these engine's oil comsumption through the intake, the intake has most likely been coated with oil which then collected and trapped all the dust that the filterless air box never caught. so there must be a pretty nasty coat of crap on the intake runners, and perhaps the intake valves...

4. car has decent compression at around 165-185

5. The car dynoed 382/361 in 2006. a recent dyno from when I got it showed only 345/340. So I know there is a bottleneck of power somewhere in there... It's one of the things I listed I'm sure.


I figured I take it to the track and see how it perfoms. as disappointed as I am, I kind of expected these numbers, however I was wishing I'd hit at least 12s and mid 11x traps...

The mods are

2003 Z06
VR intake with KN filter and powerduct
LG LT Streets (banged up pretty bad)
Corsa Pace Car catback
Dyno tune
Continental ExtremeContact DW with full tread @24psi

I also had a velocity stack on there, and realized it didn't do crap and after taking it off I almost gained 2 mph lol

Out of 4 runs, I had bad 60's on most. the 1st one I missed 2-3 and 3-4 because of my crappy master cylinder that makes it really hard to shift

2nd one I got

60 - 2.655 (spun like crazy, still trying to get a feel for the clutch/power)
1/4 - 13.781
MPH - 107.61

3rd one was

60 - 2.362
1/4 - 13.437
MPH - 107.62

finally on the 4th I took out that POS Velocity Stack thing and had a better launch

60 - 2.160
1/4 - 13.117
MPH - 108.39

Now these times are horrible for the mods I have. I should be trapping near 120 and be in the low 12s, but I know I'm having some kind of a bottle neck somewhere...

just wanted to share I guess. I know I have to clean that intake and get the longtubes fixed.

Just bit disappointing

 

That is dissapointing. Hope you get it figured out.

 

Don't be discouraged... It takes time to get to know the car. Honestly, those aren't as bad as you'd think. I've seen guys in stock C5Z's going high 13's to low 14's!

Were you power shifting? Were you spinning after changing gears? It's possible the track wasn't prepped well. On that last run, it looks like you were losing time and speed in the shifts because you should still be trapping higher. Especially for the power you're making. Any idea what the DA was?

If you're not power-shifting, I would suggest you try that next time. My car dyno'd 355 (Stock) and went 12.6@115, but I power-shifted the whole way through (even 3rd to 4th) and my 60' was the same as yours, 2.1x.

 

Dont be discouraged. How often do you go to the track? From your 60's it seems like you need alot more practice. Your car defientely has mid to low 12's in it. You just need to get more practice launching it and shifting. I have seen a Newer Dodge Viper run a high 13sec run cause the driver did not know how to drive the car. Power is useless if you dont know how to put it to the ground. Search rangers launch techniques its very helpful and practice.

 

Thanks guys.

I used to go to the track alot. I've been going for the past 8 year or so. thing is all my cars were automatics, including the turbo trans am that did low 11s. So coming to the track with a non muscle car and manual makes it a whole new experience. especially launching it

I did not powershift, because simply I don't know what it is, and reading ranger's post about it, I didn't really get it. perhaps that might help.

I was spinning 1-2 gear.

Also My master cylinder has taken a crap and for a few months, I can't get it changed because I don't have the money for a tick master. I thought about doing an OEM master and trying to keep it clean like ranger has said. I would like to just spend the money and get the tick though and have someone install it.

the shifting was bit of a problem. the 1st run, I missed 2-3 and 3-4 because it's so damn hard to shift that car with the messed up master cylinder. so on all the other passes I had to shift kind of slow to make sure I did shift. that might have lost me about 3-4 miles maybe...

I know I still have the problems so once fixed it should make a big difference

Thanks guys

 

u need tires....then youll be in the 12's

 

You could also have a slipping clutch which hurts mph. What was the density altitude? At DA of 10,000 ft = 103-104mph, 5000 ft mine would trap 108-109. <0ft = 115+ mph. You can lookup past DA's here:

http://www.dragtimes.com/da-density-...calculator.php

 

it might have been slipping due to the fact that my pedal wasn't coming up all the way. which I will get fixed as soon as I can afford either another stock master cylinder or the 7x the cost tick master

the DA was 202

 

I'd probably change the slave before the master. I replaced my clutch, tranny, slave, added a Tick remote bleeder, insulated the line next to the exhaust, but left the original master. Using Ranger method its been perfect- hot laps are no problem now.

Cool you had a TTA - I have a couple TR's

 

I've done the ranger method. I think it's too late for that, the seals have been lost to bad maintance I guess...

The slave is a major PITA to do, i might as well try the 50 dollar OEM master and if that don't do it, save up and get a clutch and have them do the slave at the same time.

FYI, I didn't have a 3rd gen TTA, mine was a '97 Trans Am with a GT70 rear turbo. still made good power though. ran low 11s with a built 4L60E

 

Just did a compression test, everything was between 205-210

While at it, I changed the plugs to TR5s gapped at .40

all 7 plugs looked to the be stock AC Delcos with one plug that was a TR6 gapped at .60

That might have helped a bit.

wires are MSD

 

Practice, practice, practice. With similar mods as yours I ran a best of 12.2@118 on street tires. You really need to get the tires hot or you'll spin or wheel-hop

 

I highly recommend NOT power-shifting until you get your master taken care of.

Basically, power shifting (AKA "no-lift Shifting") is when you don't take your foot off the gas peddle while shifting.

So as an example, if you were shifting from first to second, you'd keep your foot pegged on the gas and in the fastest single motion you can do possible, you'd press the clutch, shift and depress the clutch (popping the clutch), which will save you time from depressing and pressing the gas AND keeps the motor ramped.

By doing this you can shave 1-2/10ths off your times easily. I shaved nearly half a second off my times. If I get a chance next time I'm at the track, I'll record the power-shifting.


Now, the reason why I'm saying you SHOULDN'T do it until you get the master fixed is because you will over rev the motor big time if you miss a shift. That's just going to bend a rod or worse. So fix your master cylinder and then practice launching and power shifting.

What worked for me in practicing power-shifting was finding the slowest pile of crap manual transmission car and trying every single possible way to make that car faster without modding it. (Driver mod, basically)

 

It's a terrible idea to be running any car hard when the clutch hydraulics are malfunctioning. Doing so is a straight path to trashing the transmission through missed shifts and shift refusals. Fixing the tranny is one of the few repairs more expensive than replacing a clutch.

Regarding the clutch hydraulics, take a look at the Fast List times for bone-stock and bone-stock except CAI and DRs. Everyone one of those drivers achieved those times with stock clutch hydraulics. Most also run only clean fresh fluid in the clutch.

Here is an example of a simple bolt-on Z06 on DRs, stock hydraulics, clean clutch fluid and about 50K miles on the cars and clutch. 11.66 118.95. Car later ran 11.42 with better driving, with no further mods.

No need for an after-market master cylinder. Just clean clutch fluid on a stock master with 50K on it. No power shifting.

This video plays in HD and full-screen at youtube.


Ranger

 

Ranger, I've cleaned the clutch fluids about 20 times now. I used Castrol LMA. I think for my master, it's just too late from the previous owner...

I was thinking a wagner master cylinder that rock auto sells for like 65 bucks...

They also have a brand called Rhinopac, Dorman, Exedy

Instead of spending 300 bucks on a Tick master, I'll probably just get one of these first and keep the fluid clean, hoping it'll solve the problem...

 

Everything the car does depends on the clutch and its hydraulics.

That said, the implications of bad decisions rest with the owner.

I recommend staying with the GM OEM master cylinder. It's proven on tens of thousands of Corvettes, even hard-driven ones like mine and other racers'. If the car will be driven aggressively, the only requirement is to keep the clutch fluid clean and run DOT4 not DOT3. You want the latest OEM part number for your VIN. Any of the Forum GM-Parts vendors will sell you the latest master for about $100.

If instead you swap the malfunctioning master for some store-brand that's not proven in Corvettes, the likely outcome is continuing clutch issues.

As always, I try to recommend proven solutions at the least cost, in this case a new OEM master at $100, plus one hour per year of fluid maintenance that costs less than $20 out-of-pocket.

As for the Tick, jury is still way out due to a very small installed base and few miles and passes accumulated. The guys I know with Ticks installed still do the fluid maintenance. Meantime, with the same fluid maintenance, my OEM masters have been perfect thru a combined 773 passes at the track and 100K street miles in 3 Z06s.

Once again, I'd suggest staying away from the track and aggressive driving until the clutch issue is resolved. Your tranny and clutch will thank you.

Ranger

 

Looks like it's the launch that's getting ya. The 60'ft times blow donkey nuts

 

Sorry but the truth hurts...taking a car with problems to a place where it has to work the hardest isn't a good idea. Get everything fixed, then see where you stand, everything said is all a guess until the car is functioning properly. Be a good owner, take the time to sort out all the little issues, then come back and see where you are at.

 

Thanks ranger. I'll just get the OEM one. I honestly don't want to spend the money for the tick. I really don't think I need it. you're right about the OEM thing. it's not like every C5 has this problem.

Hawaii50.

yes, you're right. she wont' be tracked until I fix her around february. but she will get a run once fixed and it's still cold out

 

It's not too bad to do the tranny while replacing the clutch, all the same stuff has to come out anyways. I had mine out by myself in a afternoon with no lift and hand tools. Took another weekend to get back in, by myself with the same hand tools. Hardest part is cleaning everything of road dirt and removing/installing the mufflers. Lots of swearing involved too by ones self.

$2400 for a RPM level V. I shipped mine for $140 freight from FL to IN and had it back in a week. This trans is the best mod I've ever done. I haven't missed a shift or had it pop out of gear since! http://www.rpmtransmissions.com/c5pricing.html