C 5

In this thread I'm going to share my journey from a stockish 2008 z06 to a mainly street/strip car. Katech #32



August/july - 2014:
After searching for a z06 for months I've decided to take a look at a 2008 z06 that appeared to have been modified by Katech. The z06 had 29,000 miles, had a cam that and longtube headers that was later found to be katech torquer 110 (after contacting katech). Under closer inspection the car was pretty much stock with the exception of 1 7/8 Kooks headers. The very first thing I had done was take the car for complete fluid flush/spark plugs/checked the exhaust valves, and checked the tune and bought a Halltech Killerbee intake. The car put down 470rwhp and seemed to run extremely rich (10.8 AFR WOT) after a retune the car picked up 65rwhp. Couple weeks later I ordered a set of pilot super sports in 285 and 345 widths.
February 2015:
I knew the trans and the clutch wouldn't hold up to the abuse that I was putting the car through forever, after racing the car in one form or another every week the transmission had to have been rebuilt (although I knew it was on its way out as soon as I got the car).
For this reason I planned on going to a built transmission and differential through Rick Kim at RKT56, I ended up getting a built tr6060/diff/c5 axles with a mantic twin clutch. Rick did an excellent job and even did a head gear cooling modification to the transmission. I opted for the MH3 5-6 gears for my needs.



Took the car to the track with ET Street R 305 45 17s and ended up getting a feel of the car and trying to dial it all in. I ended up up trying to make a few shake down passes and ran a best of 10.6x at 133. I ended up trading my fenders for a set of grand sport fenders as I've always been partial to them over the z06 style.

Early 2016:
At this point I've driven about 36,000 miles and have had fun daily driving the car and figured I would leave that behind. I made a personal decision to get serious with the car and make it a fair weather car that had a primary objective of running some serious times and still being able to be driven. At this point I was on my second, soon to be third clutch. I decided instead of chasing numbers with a 6 speed it would be wiser to go automatic. I opted for a Level 6 4l65 conversion from RPM transmissions. To save some weight I ended up going with Race star industries drag pack that allowed me to run the serious tire I needed to, for this I picked up a set of drag spindles.


for the next set of modifications I wanted to get a bit more power out of it, seeing as the car would be in the high RPM range, I wanted to get a cam to match that, as the torquer died out fairly early. I went with the BTR stage 4 cam and the MSD air force intake


Spring/Summer 2016:
Ordered a set of weld RTS S71s, considering putting a small shot on the car, 100-125.

C 5

Since the fall of last year I have been running with dumps (for weight savings) on the car.
The car with the dumps after the X pipe saved a good bit of weight, given that the car was no longer a pure daily driver at this point, I also decided to keep it on the drag pack pretty much full time. I ordered a set of burns stainless 6.5 inch mufflers to still keep the weight down, but not restrict flow. The car was dropped to get an exhaust system fabricated and match the breathless GT2 diffuser. Here is a picture of the burns stainless muffler with a size comparison.

demonio1023

Tame yet effective build! Where does the nick name, "School Bus" come from?

C 5

Well I never really had nicknames for any of the cars I've had always just referred to them as "the z06 or the cobra" or such. I couldn't come up with a name if my life depended on it, but after I beat a few friends and people on the street a buddy of mine started calling it the school bus (hence the color) and it handing out loses/lessons. Eventually it stuck, as corny as it is, I think it adds character. I thought it was pretty comical and decided to stick with it once others started catching on to it. Heres a video of it leaving on the street. Leaves just about as good as it does at the track!

C 5

Until yesterday I haven't driven the car in a month and a half, I had a little incident where all of the four brakes locked up on me at 135 and almost killed me and a good friend of mine who ended up sacrificing his terminator in the situation. Since then the car has had basic repairs and suspension repaired. I ended up selling my race stars and buying a set of welds for the car, took the car to get a lightweight exhaust system fabbed up from after the headers on back, full 3 inch system. Another issue I have to sort out is the high coolant temperature. I got as high as 240 degrees in traffic today. I will order a remote transmission cooler and mount it away from all of the heat.

MTBSully

So your brakes locked up at 135, your buddy wrecked his cobra? What happened? How is the cobra? Pics? You can't just drop a bomb like that and not give details. Glad you are alright though. Was it active handling related I assume?

I see you are working on some halo tail lights!

C 5

Yes active handling locked all four up. I was leaving my buddies shop where we hang out and wrench after hours, there is a long stretch of 4 lane highway around the way that's very straight, decided to do a hit there, as I was off the gas and coasting I applied minimal braking to start slowing down. No abrupt inputs like hitting the brake to the floor or anything, and the car got unsettled, took a very hard left, and ended up spinning for couple hundred feet. At one point I was sideways and he was behind me (and my car being at a 90 degree angle) he avoided T-boning my car and took a hard right to avoid me, sadly he cobra was a total loss, he made it out with just a bruise and some scratches. Luckily we were the only cars on the road that night (I wouldn't of done it otherwise anyhow). After looking over the car we've concluded that it was an active handling malfunction.
As for the halo tail lights, yes, I love them, unfortunately water got in the capsule that mike supplies with them and that's why I was pulling it, Otherwise I love the single continuous halo .

z06clif

Sounds to me like a breaking problem that activated the AH . Glad your both ok

Clif

C 5

Thank you, Yes it was AH.
So far this new starter (currently the 5th starter) is holding up. After I installed the MSD unit I ended up using heat wrap insulation sleeves on all of the starter wiring, and the area of the headers that come the closest with the starter. Fast forward couple weeks ago, I wanted to get the car ready for the track rental at MIR, to beat my own personal record, which at the moment is 9.86 at 133.


Next couple of weeks I hope to get the car ready for the track rental, and make some adjustments, and further weight reductions. One thing thats been bugging me is the car gets very hot in stop and go traffic (220-240) in the summer, If time allows I will end up getting a derail trans cooler w/an inline thermostat, and replace the dexcool with another fluid like a zerex, a g05/hoat fluid. In the meantime the school bus is at vengeance racing for an e85 tune.

C 5

So a little update, picked the car back up from vengeance,
I was told the new starter is taking a ****, which further complicates my issue. I've wrapped ALL of the starter wiring, put a brand new battery in, and heat wrapped the headers that's closest to the starter. Which helped and it drove fine in 90° Humid weather and stop and go traffic and started fine. I've checked the tables in the tune before dropping the car off, the tables look fine and nothing is off that should affect starting. The only thing I could think of was the factory heat shielding on the starter wiring disintegrated and caused the last 3 starters to die within weeks of each other. So I figured it was just an immense amount of resistance in the wires when the car is hot, causing them to die very very quickly. The original starter lasted 60,000 miles no issues, and I daily drove the car in traffic, rain, etc. fast forward to two months ago, wrapped everything and went with the MSD starter unit. Problems still persist. Perhaps it's the headers, maybe they need to be recoated. At this point it's just very frustrating as I only drive the car to the race track, sometimes a meet, but don't really daily drive the car by any means. Either way, there is some good news, my new alumastars came in, with morose ds2 bias ply front runners. This with some strange brakes all around should get me closer to my target race weight. Oh and did I mention 55 gallons of e98?



Car ended up putting down a bit more power over pump gas (93 here in Maryland) and seems to have better driving characteristics.


The waviness is from the 15s on the car at the time of the dyno pull. Definitely feels stronger, can't wait to go to the track and hopefully pick up some good slips.

C 5

So I went to the track tonight, weather was perfect, 50°, not very humid, last test and tune Wednesday night for 2016, so I decided to take advantage of the weather. Drove approximately an hour and a half, Tech'd in, let the car cool down this time, dropped the tire pressure to 17psi, and did a decent burnout. The launch felt pretty good, I had a good feeling it would be a decent pass. Didn't think it would go what it did with this much weight in the car. Still could of took the passenger seat, and went with the skinnies up front. I was actually on street wheels and tires up front.
It was a relief to know that the car went what it did, it allows me to go iron some kinks out and try for another PB. At some point I do want to try on a little smaller tire, the Hoosier 25.6 drag radial. My hypothesis is that I will 60 better, have a bit higher trap speed, and lower ET, as long as the track is there and I don't spin.

DaOtherOne

Great numbers and excellent 60' time

double06

As far as cooling mods what has been done Dewitts radiator or difference fans?

FNBADAZ06

Excellent times !!!!

I didn't catch it, but are you still running the 110 cam, or something different ?
edit: never mind...read further and you switch to BTR IV cam
What's your race weight with the auto in it ?

C 5

thank you. I switched to the btr 4, had I stayed with the Katech, and just threw some heads on and an intake I'm sure it would of went 9s as well. My race weight with the auto was 2980 last time I weighed the car at MIR. That was with passenger seat removed, no windshield washer fluid, and with a race star drag pack. With the welds and alumastars it's a good bit lighter. Specially with a bias ply front runner. I plan on removing a little over a hundred lbs in the future.

No cooling mods so far, just a 160° thermostat and fan controller. Stock radiator and fans. If I take the transmission cooler and go with a standalone, I suspect that will greatly help.
Thank you !

jim2527

Any chance your previous incident with the 'terminator' was due to improper wheel stagger?

C 5

Very possible. At that time I had about 12 stock c6z wheels and the tire size might of been different than I thought. So it's very possible.

C 5

Hi all, just wanted to post a little update from the No DA excuses track rental. Made a few passes, and the last one resulted in the personal best slip. The car was very consistent. I made a 2 passes on the 15 inch welds with the radial pro (28 inch tall tire) and using the same launch technique after I switched to my 25.6 Hoosier dr2 radial tire on 17s (315 35 17) and made two passes on that. As predicted the car went faster with that tire, not only did my 60 foot drop, my mph increased and my shorter times were faster. Same launch technique as beforehand. Car was very very consistent. I am still amazed how an all motor, late model street car is cutting 1.25 60 foot times on a very very small tire on stock suspension. But of course the best part of the day was actually getting to meet, and spending time with all the people there. It was great seeing everyone, part of what makes it a great event, aside from the weather and the cars.

PB pass details:



60'.............1.254
330'...........3.882
660'...........6.119
660’ mph...109.64
1000'..........8.060
1320'..........9.704
1320’ mph…138.93

blkscls1z

Nice runs! What was your launch technique?

C 5

I apologize for not replying sooner, I tested and tried many different techniques, what I found works best depends on how the prep is. If the track seems to be working well, I try to be as aggressive as possible. For the PB pass I staged early, stalled it up, rolled into the second beam, and footbrake a little before it starts to push through the tire. Right before I launch I flash it a little higher as I get off the brake. Foot braking as high as I could before I pushed through the tire only netted me 1.3x 60s.

As far as the school bus build, I haven't been as proactive as I should have since I've been busy with life and other things. I sold the ls7 intake to oil pan, originally I planned on going to a single front mounted 88mm with an a2w setup, while I would still love to do this, it's not in the cards right now. Just between the air to water setup and the turbo I was seeing 4500$+ figures. So as it stands I plan on going with a iron 6.0 based 408 and throw a 300 shot. I loved how my car drove on motor, don't want to deal with the issues of forced induction setups (overheating, cooling, oiling, and chasing down vacuum leaks, etc). My car drove perfect before hand, Just didn't have enough mph for my liking. Unless something changes, that's the direction I will be heading.