New track times for ZZ4 cam

[96ImpSS]

Since the trans on my 302,000 mile pickup is now rebuilt and again solid as a rock, I went to test n tune today to see what the truck would do with the ZZ4 cam and the Yank SS3600 converter. It spun every run, but still ran 14.3's @ 92 on all 8 NA passes I made. I sprayed the 50 shot on the last pass, and even though the starting line didn't do it any justice, also eeked out a new best of 13.69 on the juice.

[fast 95]

Nice time for such a heavy truck.

[gmc406]

Good rip, I wish I had spray. Sounds like fun.

[96ImpSS]

After yesterdays's outing, I've decided I need to do two things: Get rid of the crap GovLok diff and do something about the wheel hop/axle wrap on the start. It's impossible to keep both tires spinning in the burnout, and the engaging/disengaging of the diff with slicks is pretty violent...only a matter of time before it goes kaboom.
Also, the axle wrap is clearly worse with the hard hitting Yank 3600 compared to the Vigilante 3000. It cost me a LOT of 60' time. I've always known there is an issue with extreme pinion rise in high traction/high torque situations, like heavy throttle in low gear when towing with a lot of tongue weight. The driveline shudder is very evident when that rear U-joint operates beyond it's angle limit. At the track without the weight, it results in complete unloading and hop/spin.
I have a practically new Eaton 400lb posi that came out of the Impala when I decided to run a spool in it, so that will solve the diff issue. On the other issue, keeping the pinion down, I'm thinking Caltracs. Anybody know of another solution that is just as good and possibly cheaper? Maybe a pinion snubber mounted on a drop-down crossmember between the frame rails?.....of course I'd want to remove the snubber when hauling heavy loads.

[custm2500]

Caltracs are a great option. The better option is a full 4 link with coil-overs or bags. Just a slight difference in cost. Not much of coarse!

[SimpleGreen]

Cool deal.

I can't wait to get some times in my truck. Should run into 13s on motor with a better stall and some traction.

[96ImpSS]

Cool deal.

I can't wait to get some times in my truck. Should run into 13s on motor with a better stall and some traction.
I agree. With your weight and a good converter, 13's are right there.
FYI, the Yank SS3600 converter looks to be worth about 4 tenths in the 1/4 mile compared to the Vigilante 3000 that was in it prior to this year. The Vig did not have the punch off the line to wrap up the leaf springs and spin/hop like the Yank does now. And even with spinning/wheelhop, the Yank improved the motor-only times by 3 tenths. And it's even snappier response in daily driving than the older-technology Vigilante. It's a very tight feel at partial throttle, but flashes up there when you put the torque to it. RPM's stay above 4000 rpm after each shift. I expect 14.1's to 14.2's next time out with some traction bars to keep the tires glued down.

[SimpleGreen]

Ya. I only have a TCI Saturday Night Special. I can squeeze a little more than 2,000RPM out of it. Id like to toss some more converter in it and rebuild my TH400 before I hit the track. A friend of mine is running mid-low 14s in a stock Vortec 350 step side...and I have 110HP advantage over him so the numbers ought to look good.

[crossy's son]

Cool deal.

I can't wait to get some times in my truck. Should run into 13s on motor with a better stall and some traction.

Doesn't your truck have a TH400 and 3.42's in it too?

Remember compared to 700R4 trucks your TH400 truck may be a tenth or two slower because of that massive trans.

[SimpleGreen]

Doesn't your truck have a TH400 and 3.42's in it too?

Remember compared to 700R4 trucks your TH400 truck may be a tenth or two slower because of that massive trans.

Its that TH375 mix bred thing that was in 454SS trucks.

Even if the trans is slower the motor will more than make up for it :D

[crossy's son]

Yea for sure.

The TH375 is a TH400. lol nuff said.

TH400 with small output= th375

[CustomChevyGuy]

always nice to hear other members running their trucks at the track.. im guessing it was a 1/4 mile?

[whitelightnin92]

mine wont be hitting the track this year...... needs a rebuild, but not to worry 383 build is in near future! along with 4.56s.. 14s here i come!

[crossy's son]

mine wont be hitting the track this year...... needs a rebuild, but not to worry 383 build is in near future! along with 4.56s.. 14s here i come!

I'll start the bidding for your old motor at $100.

:lol:

[whitelightnin92]

I'll start the bidding for your old motor at $100.

:lol:

:lol: too bad cause im keeping it

[va454ss]

Anybody know of another solution that is just as good and possibly cheaper? Maybe a pinion snubber mounted on a drop-down crossmember between the frame rails?.....of course I'd want to remove the snubber when hauling heavy loads.

Put 4* of pinion shims on each side. You'll want to install them as to point the pinion down.

Clamp the leaf spings tight together in front of the axle. Install polyurethane leaf spring bushings.

[96ImpSS]

I put the Eaton in today. One of the spider gears in the GovLock diff had a tooth broken off, probably from last weekend at the track. Glad I finally got that POS out of there!

[Pauly]

Nice times Pat. Looks like I will be looking at a Yank TC when it comes time to do a TC.
If you had to do it all again, would you do teh ZZ4 cam again, or would you do something else?

Thanks

peace
PAuly

[96ImpSS]

At first I wasn't very impressed with the ZZ4 cam, but the more low rpm/low map timing I threw at it, the better it got. I'm very happy with it now. All other things equal, it was worth at least .3 sec under the stock cam, so that's about 35 hp in a vehicle this weight.
After clamping the front leaves in combination with installing some old slapper bars, I ran it last weekend. Hot, low pressure day, so ET and mph wasn't there, but it picked up .10 sec 60' time on motor, from 2.00 prior to 1.90 now. Pinion angle is ever so slightly up with the front of the leaves clamped, but even under acceleration, it's restricted to not much more than its static angle now, so there was no hop or spin.

[eltravo2008yo]

At first I wasn't very impressed with the ZZ4 cam, but the more low rpm/low map timing I threw at it, the better it got. I'm very happy with it now. All other things equal, it was worth at least .3 sec under the stock cam, so that's about 35 hp in a vehicle this weight.
After clamping the front leaves in combination with installing some old slapper bars, I ran it last weekend. Hot, low pressure day, so ET and mph wasn't there, but it picked up .10 sec 60' time on motor, from 2.00 prior to 1.90 now. Pinion angle is ever so slightly up with the front of the leaves clamped, but even under acceleration, it's restricted to not much more than its static angle now, so there was no hop or spin.
did you try the spray with the new setup?

[96ImpSS]

did you try the spray with the new setup?
No, it was an impromptu track visit with a full tank of 87 octane. Even with motor-only, wheel hop was previously severe, and is now good, so I'm confident that issue is fixed.

[eltravo2008yo]

awesome. i put clamps on the front of my springs and it fixed wheel hop on the street.

[96ImpSS]

I finally ran it again Friday night. At a slower track. NA was 14.40 @ 92.x On the 50-shot, just barely improved with a 13.67 @ 96.3 compared to the previous 13.69 @ 96.2.
But new best 60's both NA 1.88 and juiced 1.76
That 1.76 is a .03 improvement, so I can see a 13.5x in it, on the right day at the right track :)

[RPMbagged97]

nice times. The only mods done to your truck are the ones in your sig? and your in the 14s? What springs did you go with for the zz4?

[C/Ktruckfan]

nice times. The only mods done to your truck are the ones in your sig? and your in the 14s? What springs did you go with for the zz4?

I think I remember him saying he used the Crane 10309 spring/retainer kit......

[C/Ktruckfan]

double post......

[96ImpSS]

Yes, all performance mods are in sig.

I'm almost reluctant to share what valvesprings I'm using. I'm certainly not suggesting anyone follow me!
C/K, yes I did use the Crane 10309 kit initially. However, they were used, and evidently abused; within 3000 miles I had broken two of the exhaust springs. The second one dropped/bent the valve; nothing hurt, just had to pull the head. Live and learn.......I thought with only .510 lift and never seeing 5500 rpm, they'd be fine even used, but they evidently had the livin crap beat out of them before I got them.
After that ........here's where I'll get flamed! .........I put in a new set of the GM "Z28" springs that I had in the garage, along with ghetto-ground stock retainers (lighter than the Crane retainers) Those springs are slightly big for the pockets, but you can rotate them until they sort of "find a happy spot". I pulled the covers at about 1000 miles and they looked straighter than when installed. They have about 70,000 miles on them now. I'm running GMPP 1.6 rollers on the intakes and stock stamped rockers on the exhaust.

PS..........still pumped about the lastest runs with the Impala on Sunday (see sig)! Despite horrible traction and a best of the day 1.53 60', the Fall air is rolling in and resulted in a new best. It's the world record holder for 350/355 NA Impalas.

[C/Ktruckfan]

Man Pat that B-body is mooooving !! Just posted on ISSF a congrats and want to give you one here also.......nice job. On the truck, have you considered increasing the "dosage" of the shot a little?

[va454ss]

It's the world record holder for 350/355 NA Impalas.
:burn::rocking:

[96ImpSS]

It's just a very crude and simple dry system. No fuel going in with the nitrous. The nozzle is aimed at the MAF sensor, and with the 50 shot it seems to fool the MAF just right into "seeing" more mass airflow. The PCM bumps the injectors about right, since I'm seeing about 900 mV on the O2's. I've tried a 75, and the O2's drop to about 860 mV, getting a little lean for my liking.

[Fast305]

It's just a very crude and simple dry system. No fuel going in with the nitrous. The nozzle is aimed at the MAF sensor, and with the 50 shot it seems to fool the MAF just right into "seeing" more mass airflow. The PCM bumps the injectors about right, since I'm seeing about 900 mV on the O2's. I've tried a 75, and the O2's drop to about 860 mV, getting a little lean for my liking.

I wonder if you are out of pulsewidth and duty cycle or if its just maxing out the maf.

I am considering putting my 5.7 on the bottle and looking at how your truck responds to a 50 shot, I might just have to do it.:burn:

[96ImpSS]

I wonder if you are out of pulsewidth and duty cycle or if its just maxing out the maf.
My guess would be the former. That same part number MAF meters air up to at least the 450 rwhp level.

[Fast305]

My guess would be the former. That same part number MAF meters air up to at least the 450 rwhp level.

I seem to remember the black boxes having a very low GM/SEC maximum on them. But 22# injectors on a 50 shot with your engine would probably be fueling around 425 HP.