Well, a few a you that are friends with me on Facebook already know this but I *FINALLY* got my much sought after 10 second time slip last night at the local test and tune track.

Car: 1996 Z28 coupe
Engine: 5.8 out of a 2002 Silverado.
__ Cam: Isky "Triple 12" - Dur @ .050 = 212/212 Lift = .56x/.56x LSA: 112
__ Heads: PRC Stage 2.5. Brian Tooley springs. Trunion upgrade
__ Intake: stock Ls1.
__ Fuel: E85 pumped by twin intank Aeromotive 340's. Feed/Return: -8AN/-6AN PTFE Steel braided. Fuel Pressure(58psi) Regulator: Boost referenced Aeromotive
__ Injectors: Bosch 127#
__ Power Adder: PT7675 .96 A/R set to 17psi via Turbosmart manual Boot controller. Front Mount Intercooler(3")
__ Exhaust: Full exhaust, CXR hotside going to a standard Borla catback.
__ Tune: HPtuners. Tuner: Myself ��
Transmission: Old school TH350
__ Transbrake: Yes
__ Torque converter: PTC brand (Not Precision Industries, not Vigilante, etc) stalled to about 3,000rpm
Differential: Ford 8.8/GM 10 bolt hybrid with 3.55 gears.

So about a month ago, the car had 3.08 gears(I thought they'd 'load' the turbo more effectively) and a 4300 stall Vigilante Torque converter. I took that to the same track and while the ET/MPH(11.3/120) wasn't bad, the RPM's were only dropping 200 rpm or so on each shift. That's what they refer to as 'blowing thru the converter', meaning, the Torque converter couldn't hold the load placed on it.

I conferred with Ray Cahall about it and he said my setup (stall and gears) were all wrong for my setup and it was completely outside my TC's efficiency range. He suggested sending the Vigilante TC back for a restall to something like 3000 and putting 3.55's back in the differential(which is what I'd just taken out to put in the 3.08s) .

Meanwhile, I read a lot of posts about a guy named Dusty Bradford with a TC company named "PTC". I contacted him and he said he could fix me up with a custom converter. I ordered it and some new 3.55's and when they arrived, I installed them.

Last night, I went to the track. I'd recently installed the wiring/switches to use one momentary switch connected to 3 arming switches so that I could independently or in combinations, activate my 2 step, the Transbrake and the line lock. They're all contained in my ashtray cavity. Just open the door and there they are. I arrived at the track early and went from the freeway to the staging lanes, having already reduced the M/T 315x35x17 drag radial pressures to 17psi before leaving the house. The car had tools in the hatch, full tank of E85, the heavy ZR1 wheels all the way around (9" wide rims with 295's on the front and 11" wide rims with 315's out back). After being called up to stage, I backed into the waterbox, armed only the Line lock, pressed the button and cleaned/warmed the tires, letting go of the button and spinning out to dry them and pre-stage. This being the first time with this new combo of TC, Gears and the new switch for transbrake, etc I was a bit nervous as I entered the staging lights. Once the prestage and staged lights lit, I armed all 3 switches, held down the brake pedal, then pressed the momentary switch, then floored the gas. To my dismay, the car started pushing out of the staging lights. The transbrake wasn't working. Ugh.... So I let go and took off anyway, deciding I'd diagnose the issue in the pit area before my next run. This netted an abysmal 2.19 sixty foot, an 11.3 ET and a MPH of 128.

Back in the pits, I lifted my switch panel to see if anything had disconnected on the transbrake. Sure enough, the spade connector had slipped off. I reconnected it, then tested the activation. It Works! So I quickly got back into the staging lanes and awaited my turn.

As I sat there waiting, staring at the time slip I'd garnered on the first pass, I saw the sixty foot as an indication that I might be able to get into the 10's if I got off the line to a decent 1.6 or 1.7 sixty on this next pass. When they called me and a nice looking WRX up to race, I repeated the cleaning/warming of the tires, then pre-staged. The WRX prestaged then staged fully. I bumped into the 2nd stage light, armed everything, stomped the brakes, hit the button to activate the Line lock, 2 step and Transbrake, said a prayer, the floored the gas. By now the yellows were coming down and I felt the 2 step limiter doing its job and the transbrake was working ! On the last yellow, I 'sidestepped' the momentary switch. Holy cow... It didn't spin and I felt like I'd been shot out of cannon. I'm not going to lie, it was awesome and scary for a second or so. I almost felt light headed. More proof of that disorientation was that I shifted from 1st to 2nd at a meager 5,200 rpm, about a 1,000 rpm early. I watched the tach for the next shift and shifted at 6,100. Looking in the rear view for a moment, I saw the WRX was way back there, like in a different zip code.

I quickly braked and waited for the WRX to turn off first as is protocol for the car/driver closest to the return lane and headed anxiously to the timing booth. He handed me the slip and I drove away. Not having my glasses on, I couldn't readily tell what the numbers were as I idled back down the return lane. Then my curiosity got the better of me so I reached over, picked up my glasses from the passenger seat, put them on and quickly glanced down.
Sixty foot: 1.5
ET: 10.629
MPH: 128.94

Woot!

I was warned back in the staging lane that to race there any more, I needed to have a cage and a single layer fire jacket (or to limit my passes to 11.5). I didn't care, I wanted to head home after the 10 second slip anyway ��
I pulled back onto the highway and drove home.
Thanks to Brian and Tiff for inspiring me to go Turbo Fbody!

 

Congrats on the paas, and big ups for still being able to drive it home after the festivities!

 

Thanks and Yes, the fact you can drive your car to/from the track without a worry is a big plus after such a performance.

 

Congrats after all that hard work and learning curve on your tuning! Don't 60 foots like that feel great? Especially after driving there!

 

Congrats DAVE! I wish you had that auto back when your LT1 was boosted.

 

Me too Jon. I never got a chance to change the TC and put the TH350 back in.

 

Congrats, nice pass-you should get a job as a writer, lol

 

Congrats man!

couple questions, what do you weigh? How much timing? Have you monitored backpressure at all? Trap seems maybe a little low for 17#

congrats again man, be running 9's in no time! Dusty did my converter also!

 

Congrats! That's quite an improvement.
and you short shifted it big time. Been there done that!
until you get a bunch of seat time, turbo cars will make you look like a spaz for sure.

Gonna put a cage in now?

 

hell yeah that car is running really strong!

i bet you could get some more mph too

 

Agreed, man I loved reading this story. Pure awesome. Congrats on the time.

 

Nice job. Congrats on the 10 second pass. Drivin' em there makin passes (fast ones at that) and drivin em home is where it's at!

 

Curious about the timing as well. I've been tuning a buddy's 3rd gen with a 5.3 s475 and its been 138mph on 16psi/14*.

 

TO Thanks for the kind words guys.

Backpressure: I've not measured it but I'm pretty sure it's a factor because I'm running a full exhaust. 3" outlet from the turbine goes to my 3" downpipe, back to a standard Borla catback and then to the bumper. I'm going to disengage the intermediate pipe, put a turndown on it and see if it feels better. Unfortunately, I think I've ruined my ability to race at the local track until I get a cage, so I won't be able to quantify it. I suppose if I went my local dyno, that could reveal any enhancements.

Timing. I have an aggressive timing table setup for the E85 I run. From 4427 rpm up .., no knock retard at all.
RPM Advance
4427 18
5393 17
6068 16 to redline.

 

Thanks Ron.
Yeah, I've got to simplify my switches so I can arm/use them without so much activity.

On the cage, I'm reluctant to do it since I'm the original owner. I might opt to buy a Porsche 944 roller and put a turbo 5.3 in that with a cage. Whom knows There was a time I wouldn't even put an extra screw hole anywhere in the car, just to keep it pristine. But practical needs, such as the fuel pump trap door, materialized and I'm glad I've done that in hindsight.

I'll have to revisit the cage possibilities and see if one is in my future. To be certain, there's rarely a passenger in the car so I don't have to worry much about that aspect and their comfort.

I still have twin GT 35's and a standup radiator to install this winter and I'm looking forward to that.

By the way, I wanted to ask you guys... Have you seen the new ZL1's and Hellcats and stock GTR's running at the track? There were 3 ZL1's, one Hellcat and one GTR at the track when I was racing. The ZL1's went like 12.0's, the Hellcat 11.5 and the GTR was 11.5 too. Just wondering if that's typical.

 

yeah thats about what I see. unless Ron tunes them, then they run 9's/10's

 

you will gain power/tq with a cutout. I have a dual 2.5" exhaust after my 3" DP... and with twin cutouts on the 2.5" pipes I gained 40+rwhp/70+rwtq @ 13psi.

Also, I typically see peak tq timing a few degrees lower than peak hp timing. I ran 12 deg @ pk tq and 15 deg @ pk hp on 93 + meth... I made 817rwhp/758rwtq @16psi with a slipping clutch (stock LS3 bottom and 7675). I'd be interested to see how you hp/tq change with some timing changes... if you get an opportunity to get to the dyno.

 

Pretty solid numbers on pump gas.

 

Congrats man! You are ramping timing down as rpm goes up and over peak torque? Might be some power to be had there

 

Thanks guys. I'll look into these tips. I've installed the turndown and completely bypassed the muffler system. I started it up in the shop just to see if it would be too punishing to hear, but was relieved that it doesn't seem to be that bad so far. I'll schedule a trip to the dyno to see what can be had there. It started raining right around that time so I'll have to wait for better weather to get some more seat time.