Ok guys, i need your input here. I have a 2003 coupe cammed and on nitrous, the car is on 20" rear wheels (pirellis 305x35r20) 19" on fron 245x40x19 - here is my issue, when the car shifts from first to second at full throttle she jumps a few feet to the left- so bad on nitrous that it completely throws me into the next lane. What do you guys suggest in order to keep the car from leaving its lane???

Thanks in advance for the input-

 

When I put the s.c on my coupe and 550 hp was there I had similar problem. I changed tires to a softer tire ,hankook rs3 are super soft when hot . I also installed z06 rear spring with blisteen sport shocks. Wow the car stays perfectly straight on launch unless the road is sloped to the outside , then may slightly drift to the outside. try suspension work first.

 

I'm assuming an auto by the description of "when the car shifts..."

If the car is jumping that hard left, it sounds like the transmission is tuned to slam a hard shift. Basically your momentarily breaking traction and regaining it.

Soften the shift up so that your not shocking the tires on the shift so bad, problem solved.

Be careful, if it actually manages to fully break traction on the shift, you'll be staring at a wall. Been there done that... Cold tires suck...

 

Thanks for the quick replies, yes I forgot to put its automatic- so softening the shift will help- I'll talk to my tuner regarding that, thanks again!

 

what ????,make it softer ? why ,ok then might as well take off nitrous, go back to stock and so on . At some point you must make some improvements elsewhere in order for it all to work together. You cant just make big power without changes to where the rubber meets the road. Enjoy the shifting like a standard.

 

I'm definitely going to start working on the suspension and see what happens from there- I love the power and don't want to give any of it up!

 

I can't speak for an auto, but once you start making more power, you definitely have to get everything "tuned" so it works together, suspension mods, alignment, ect, it's a learning curve and every car can be a little different, but the power serves no purpose if it can't be controlled, it could be a combination of small things.
My stick would tend to kick the rear out pretty hard under hard acceleration in 2nd and 3rd just above 4 grande, a good alignment along with good tires (Hancook V-12) solved my issues.
Lots of videos on YouTube where people have crunched their cars due to loosing traction (control) smart to make sure that power can be used as safely as possible.

 

Simply put... An automatic that shifts HARD, is not the same as an automatic that shifts FAST.... Line pressure only increases shift speed to a VERY limited extent, what it does do, is increase clamping force. The more line pressure, the harder it clamps, and the less slip you get in the packs, producing less heat.

This is not the same as how fast it shifts from gear to gear... You will reduce wear to the packs to a certain extent with higher line pressure, but there is a price to pay. Its slamming hard parts, and shocking the drive train components.

A sure sign of a poorly tuned transmission for a specific setup is one that is slamming and chirping tires in every shift. That is, unless the customer desired it... People somewhere along the line got the idea that they want an auto that chirps the tires when it shifts. Chirping tires, are tires loosing traction.



Correctly tuned, an automatic will shift when commanded, be firm, and snappy, almost seamless between shifts. Setup this way, and the car will be very predictable, and stable.


This is not to say that there is no place for suspension or tire upgrades, that would be totally false. More, that if the car was just tuned, the transmission was likely dialed up, and the tuner just made it a little too hot for the current setup...

The options for the OP being, spend money on suspension parts, or just have the tuner dial it back a bit for no cost.

 

When I did a Quaife rear diff, it helped alot with the dancing around. Less side to side action, and more grip and go! I think it works alot better than diff clutches.

 

so I lost control of her in the 1-2 wot shift with traction control off.... here is the results

 

what suspension upgrades should I do now since the car is headed to the shop?

 

tire tire and more tire.. MT ET street radial or Nt05R

 

Ouch, sorry to see this, glad your ok, car don't look too bad, good luck with everything.

 

Ever had any differential work? If the belleville washers are cracked the differential won't work properly. The quaife is a great diff, but I believe the clutch types can hold more power. I'd also suggest a differential brace, z06 springs, and stiffer shocks.

 

Damn dude... I hate to say it, but that was really dumb. You knew it was jumping around and people on here even tried to warn you, but you still kept jumping on the nitro. Lessons learned so they say..

Here is what you need to keep planted. (After the cost to get it back on the road.) Tires, an alignment, and a few suspension upgrades. Im sure like most, if it was lowered, it was never given an alignment after. You are loosing traction due to negative camber if this is the case. What Pirellis's are you running? Width pails in comparison to the importance of compound, and Pirelli does make regular jack off tires too. So running Pirelli's doesn't necessarily mean you are running good tires.

You need a stiffer rear sway bar to help keep the wheels lined up too.

Once you are planted, you are going to shred your diff and or tranny. You need to combat wheel hop before it happens. Get a solid diff mount and maybe even a diff/trans brace. Even with these, it is important to upgrade the shafts in the diff. They are a notorious weak point.

 

BINGO!!!!!!

GREAT ADVICE!!!! After i read your very first paragraph and my recommendations were to make sure that your limited slip clutches are working correctly!

Here are a couple of post that will explain how the rear end (differential works and how to inspect and improve it:

- C5, ragtopws6 , Upgrading your C5 rear with C6 Z06 guts, : http://forums.corvetteforum.com/c5-g...-z06-guts.html
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- C5, Its_Go_Time, Output Shaft Install - Left and Right: http://forums.corvetteforum.com/c5-t...post1573407966

- C5 Differential Seal replacement: http://forums.corvetteforum.com/c5-g...on-photos.html


If it has not been done already, its a great idea and perfect time to harden up the rearend. At a minimum, replace the clutches and belleville washers. so you have proper traction on both rear wheels when you accelerate.

NukeC5

Has more good info! At your power level, you need the PFADT Mount and a ECS Differential/trand brace....

Bill

 

Really, it works great for me. Mine has made up to 1000rwhp with no issues.

 

PFADT Mount and a ECS Differential/trans brace, good shocks,
good tires (summer tires not all weather)
That PFADT diff mount really made the difference on the street.
Works for me, even at some high speed cold tire runs-very eye popping but kept straight.

 

thanks for the great info, nitrous was not on when this happened. Never had differential work that I know of. The Pirellis are pzero nero m&s , trac control was turned off, it was definitely dumb of me, unfortunately when you have a corvette accidents happen. I enjoy driving my car, and I am definitely learning from this mistake.

Thanks for all the great info guys!

 

When you criticize people for doing things that they shouldn't, sometimes you have to live in their shoes and comment on FACTS.

That said,,, Do you know what P ZERO really stands for??????

Perillie ZERO TRACTION!!!

I switched from the OEM C5 ZO6 tires to Prellie PZero tires and found a significant loss of traction.

They are the ONLY tires that I have ever owned and promoted as truly HORRIBLE! From the first 10 miles of them being mounted, I almost crashed my 02 ZO6. Just ask Justin at ZIP Performance. He was in the car with Me!!

I had to SUFFER thru 25,000 miles of lousy traction and I BLISTERED the damn things as MUCH as I could to expedite their demise.

HORRIBLE TIRES with SUB-PAR TRACTION! NEVER EVER,,,,,, purchase Prellie tires!