I have noticed that if I spin the tires on wet pavement with anything more than half throttle, the engine hits the rev-limiter before the trans has a chance to shift. At WOT the engine seems to stay on the rev-limiter while shifting first thru third gear.
Why doesn't the tranny shift before hitting the rev-limiter? (at least I think its the rev-limiter as the revs are around 4200) Maybe its running out of fuel at this point? I have done the banjo bolt mod to the fuel inlet at the heads, which made a huge difference pulling thru the higher rpm's.

Any clues as to why it doesn't shift quick enough? Not enough load maybe?

 

Has it done this a couple times or many times?
Usually, it will "learn" after a time or two.

Many of these files have been changed a little (no one can leave well enough alone, lol) since I've left.
The issue is with the acceleration rate. The acceleration rate is higher (mph increase rate on the speedo) while spinning the tires than when you have traction.
It can not properly anticipate the shift because the acceleration rate it too high and it "misses" the shift.

See if it goes away. If it doesn't, call superchips and give a very specific explanation.

 

Vic,

Your PM box is full

 

When I spin my tires on wet pavement it seems to shift fine at WOT but then when you back out of it it downshifts into the proper gear for the speed and seems to get stuck in that gear for a short period.

I just figure it is the computer having no clue as what to do, with a loose nut behind the wheel.

My tuner should be coming back this week from SC. I had to get an update becuase of the new flash that i didn't want and knew it wouldn't fix my problem which it didn't. I will see if it still shifts erractically when it comes back. If it ever rains again, or better yet maybe it will snow!!

 

Remember, shifting is not based only on RPM, but MPH.

WHen you spin the tires, finky stuff happens (even on stock trucks) because the truck might only be going 5 mph, but the speedo reads 40 and it says "SHIFT!", only to cause an immediate downshift once you have traction again.

Hell, you can powerbrake the truck and burn out in place all the way into 5th gear =o) All that matters is the proper RPM is reached or proper MPH is reached (or both).

 

I should have been more clear on that I was not meaning to blame the tuner at all. It did the same thing in stock form.

 

...I blame the tuner for the following occurance:

Sunday afternoon I was on my way with the family (wife, two kids) to her uncle's house. We were on a six lane (three each way), 45mph road with occasional stoplights. I pull up next to a tricked out Nissan 350Z with aftermarket exhaust, brakes and wheels. The guy is revving his engine, so I brake torqued the X to two grand and when the light turned green I completely smoked him!! At the next light I guess he decided to try harder, as I'm sure I surprised the "H" out of him. Again, he winds his motor up and prepares to pop the clutch ... Again I brake torque the X, only this time I overdid it a bit, because on green the rears started shredding and moaning, so I let up a bit, reconnected the tires and again completely blew his doors off!!!

I really felt sorry for the guy, because there was moderate traffic behind us, and I'm sure he must have felt the ultimate embarassment to have his racy little Z car trounced so badly by a big truck -- Hahaha!!! I gave him the thumbs up as he began to turn on to the local tollway, and he reluctantly flashed me a peace sign.

SCMT ... I bow down to your greatness!!! I've never had so much fun in ANY vehicle before, and I've had the good fortune to drive some pretty slick (and fast) rides!

Regards All!!
Steve

 

The 350Z is a disappointment as far as I'm concerned.
I've seen them pull 16's at the track.....pathetic.

Still, getting the better of one in a diesel truck is pretty cool.

Have you ever been in a car that runs (I means really runs) 10's or 11's with some sticky drag radials or et streets?
It's an absolute scream.
The PSD is fun, but I dunno if it's THAT fun....

Then again, the nonsense of something that big and diesel pulling that kind of 60' is pretty damn entertaining =o)

 

A buddy of mine has a 2003 SVT Cobra drop-top (with the 5-speed), and I've had the good fortune to drive it. VERY fast and great fun, but although it'd blow away the X I have to admit that it was the novelty of completely embarrassing the Nissan guy with my entire family in the truck that made it so much fun!!

I agree with you ... the stock Z doesn't begin to live up to it's potential, but I doubt that the people around us knew that when they saw the racy Nissan getting totally trounced by the "ugly" gray truck spewing black smoke!!

Regards (and thanks, Vic!),
Steve

PS I saw a 2003 episode of "Truck Universe" where the SCT folks took the "T.U." guys to the dragstrip in an F250 Superduty along with a brand new stock '03 Mustang GT, and smoked the Mustang definitively on every run, with a best quarter mile of 13.9 at I think 98mph in near 100 degree heat with the A/C on and two people in the truck -- VERY impressive!

 

Funny part about it is that the tune they ran in the truck had STOCK boost/EBP tables and only 12 degrees of injector timing to keep it from puking in the Florida heat

It was LOADED up with fuel though, and I do mean loaded...

 

I had a 2003 Sonic Blue Cobra (by the way, they only came in manual, and only 6 speed).
Stock, it ran 12.90-13.10 (depending on driving)
Stock power (at the tire) was 360HP/333 FT LBS (superflow dyno)

After pulley, intake, exhaust and tuning, it ran 11.50's @ 123 MPH
472 HP/494 FT LBS at the tire

After removing the stock blower and adding a whipplecharger, it ran nearly 130 MPH in the 1/4 and is definitely 10.80 capable.
590HP/ 580ish ft lbs

The 03-04 cobra is perhaps the most modification friendly vehicle of our era.
I still miss that car.
It made peak torque at 3100 RPM and peak HP above 5500, and made for a LONG hard pull with instant response.

They are easily tunable into the 10's and with some effort, they can break the 9's.

700 ft lbs at the tire can easily be attained with the correct pulley, tune and a shot of nitrous =o)

 

Jim, did you do a live axle conversion on that car or just beef up the IRS?

 

You don't need to beef up the IRS (if you can drive it).
Many 10 second cobras are running stock IRS components

I prefer the feel of the live axle (plus I eliminated my IRS hitting a curb in a high-speed drift gone wrong, lol). I found a live axle cheap, and the car handles much better (believe it or not) with the live axle. Not quite as comfy, but more in control. The live axle mod saved around 150 LBS.

I didn't get enough track time with it to realize it's full potential, but it was fast enough to make people ****.

A friends equally equipped car (he still had the IRS) was running 11.40's -11.50s at 123-124 on a regular basis.
Only mods were a 2.8 upper pulley, air filter, catback, ***** blower port and a Superchips inc HP4 pulley tune.
A lot of people don't understand just how fast these cars can go.
with nearly 500 HP at the tire, your hands are full, and if you add a whipple or Kenne Bell blower, 600 rwhp is easily attained in a daily driver on PUMP GAS.

It's just an incredible engine with forged internals and and amazing ability to handle high boost.

edit: I see one of my non curse words was bleeped out. It is spelled: A-P-T-E-N, and is a brand name for a company that ports eaton blowers. I wonder why it got bleeped? Funky.

 

You guys are really making me miss my old car...
It would still make you feel like loosing your lunch at over 100mph

 

OOOPS!! It's been awhile since I drove the car ... forgot that it was a 6-speed!

If "Sonic Blue" is Ford's equivalent of Royal Blue, then your car was identical to my buddy's (assuming you had a drop-top). Royal Blue is my favorite color ... I think it looks great on just about any vehicle!

Good Fun!!

Steve