Sorry if this should be in the drag section but i would like advice from the FI crowd. I went to the drag strip yesterday and still having the same problem i had NA, NASTY WHEELHOP, so bad that even rolling off the line i broke my Fuel Lever Sending unit. After that i took as much weight out as i could and it helped.

I have Tein S-techs (G35), Koni Yellows, Kinetix arms, SPC Toe Bolts, ~1.5* Camber 0* Toe, 295 BFG KDWs, and a Solid Rear Diff Mount. I used to hop even on the street NA and had a busted Diff mount so i installed a Solid mount and it helped some, but after about a year i busted the rear diff mount stud that screws into the cover. I broke this stud again yesterday.

What is the key to reducing hop? I know DRs or slicks would but i want to fix this problem with street tires.

For those wondering i ended up running a 12.42 @ 119mph rolling off the line.

\/\/\/ CLICK FOR VIDEO \/\/\/


Had to do this to make it home

 

Do you happen to have a video of a launch?

My guess is that you are simply releasing the clutch too fast and/or going WOT too soon, and you are hopping off the start. Since you mentioned you had this issue NA, thats what Id lean towards, you are getting ahead of yourself or getting anxious at the line.

What tire pressure?

Do you get this on the street?

Are you getting the water off your tires or driving around the water box?

Curious what your 60ft was on that run?

Nice rig to get home btw

 

Replace your diff cover with teh nismo diff cover...

The new revised nismo diff cover has a stud that threads into the diff cover itself, its no longer a pressed in stud...So its stronger and replaceable...

New nismo diff cover stud:



Additional bracing:
From there, it seems your driving style may also warrant an additional braces...like this:
SOUND PERFORMANCE BRACE:

https://my350z.com/forum/engine-and-...brace-kit.html
OR
INJECTED PERFORMANCE PASSENGER SIDE BRACE:

https://my350z.com/forum/drivetrain/...brace-new.html
BOOSTED PERFORMANCE:
https://my350z.com/forum/forced-indu...on-inside.html

-J

 

I launch slightly when i broke the fuel level unit, but i NEVER just dump the clutch since im on a JWT with 40k miles. The rest of the runs i would start at >1500rpm and let the clutch out slowly, then ease to WOT, if i did that (like in the video) it seemed do hook, and atfirst this method yeilded a ~2.5-2.7 60ft but i started getting it to hook and went WOT quicker and god under 2s. Also if i slammed it in 2nd to fast it would start hopping again.

Tire pressure 33psi

On the street all i do is spin, no traction untill i come out of peak TQ in 2nd

I did a slight burnout just to clean the tires, 3k launch 3-5secs out of the box

on that run my 60ft was 1.984 1/8th was 8.144 @ 91.37

oh and thanks she made it 54miles

 

With my OE diff cover the stud just threads in, thats how i replaced the last one, and i have a Nismo cover but im waiting until i swap to a 3.3 to install. And ironically i just bought an Injected Diff brace last week but havent picked it up yet

 

Heres the entire album, GF took the videos and i have'nt even had time to watch them, so you may find a better one of the launch
http://s154.photobucket.com/albums/s..._334/MMP%20TT/

edit: maybe this one can give you an idea

 

With a 1.9 60ft and 119mph worth of trap you should have been 11's EASY. If you can hook that decent you just have to do your part to keep it from spinning in 2nd gear, then nail shifts and its there.

My bad I didnt realize that was a video I just now clicked it but cant hear your car well over the other.

Have you ever tried slightly lower pressures to see if it helps? On a few occasions (when I was NA) when the track prep wasnt that great and Id start to hop, Id lower down to 25 or so psi, and it would smooth out. I wouldnt go to low, they arent DR's after all.

 

yea thats what i thought, i was trapping the same as a GTR running 11.4. I know i really just need DRs but i hate to spend the $ when im trying to build a block.

I also tried lower pressures when i was NA and it didnt help with the hop at all, so i didnt bother yesterday, the only thing i found that helped was removing weight from the rear.

I know my rear springs are extremely soft, i think softer than stock, and thats why i added the Konis but do you think that could be part of it? I didnt go Coils because i didn't care to lower it anymore than what it is and im cheap

This is the video where i busted the fuel level sensor

 

The next step would def be to try to play with the shock settings, Im not too familiar with Koni adjustment. Go stiffer in the back and see if that helps the issue.

Soft in the front to help with weight transfer.

 

Both front and rear are all the way stiff, ill try to adjust the front soft next time, and i hope the Injected Brace helps, but i bought it more as an insurance policy to keep from leaving that diff behind when if the stud breaks again

 

THis is a problem I have seen on my g35 coupe also and I am NA I thought It was my suspension to blame

 

I don’t think the Injected brace will do anything to prevent wheel hop (that’s a picture of mine installed above), I installed the Injected Brace when I was N/A and I didn’t notice any improvements at all (solid differential mounts fixed my wheel hop issues so far), but I also installed it as insurance, maybe it’ll prevent something from breaking.

Edit: Were you pushing 484 whp when you were trapping 119 mph?

 

I suggested the added brace because he already has solid diff bushings...look at his pic...

the addition of the stronger nismo diff cover and stud will help as well, but if he breaks another one, then he at least has a brace holding his diff rather than ratchet strapping his diff to get home......plus a nismo diff cover stud is replaceable (threads on and off)

-J

 

The nismo diff cover has more meat in the inside of the diff cover compared to oem.....

The oem diff cover is not beefy on the inside:
Diff cover crack coming from OEM stud location:

PIC TAKEN FROM HERE:
https://my350z.com/forum/engine-driv...e-install.html


-J

 

stiffen up the rear and problem will be solved. also check tires pressure as well, i would look into your camber also

 

My solid mount helped some when i was NA but i keep snapping them, and yes i hit 10.4psi on that run and i made 484rwhp @ 10.3psi and even though most people dont believe it Z1s dyno reads low for a DJ, compared to another DJ about 70miles away it reads 9% lower

EDIT: and i feel like i should have hit 120, i hit the limiter as i crossed the line, i have a 27.1" tall rear tire (295/35/19) and 7k rev limit

 

idk, but doesn’t that 119-120 mph trap seem a little low for 484 whp?

Single turbo Z here trapped 116 mph with 373 whp.

I’m heading out to the strip this Friday for really the first time since I boosted my car, we’ll see what happens…

 

considering no launch, starting from 1500rpm id say thats about right

 

SICK DIY!!

 

That’s exactly what he’s doing on the launch, really just a 1st gear rollout on street tires (I actually drove it down the track last year). I was hoping for a trap around 112 mph this Friday, trying to figure out what I’ll be able to manage, lol

Are you finishing in 4th gear? I think in an 6MT 03/04 G/Z 4th gear should take you to 117 mph at 6600 rpm (with factory size tire)