PFF - Pennock's Fiero Forum, PDA Edition

3800SC/ F23- Any real need for an LSD (Page 1/1)

cam-a-lot

MAR 25, 07:37 AM

Hello

I am getting a spare F23 built (swapping gears from FY1 cobalt trans) by a transmission shop with experience in working on F23 transmissions in J Body cars. The mechanic has installed an LSD into his Cavalier and asked if I want one

My car is really just a mid life crisis..Sunday afternoon/ Friday night cruiser. I like to step on it on occasion and have not really had any issues with traction- except when both tires let loose. No plans for drag racing/ slalom, anyhing aggressive beyond occasional spirited driving on winding country roads

Can someone explain to me what (if any) benefits there are with installing an LSD in my situation?

thanks

ericjon262

MAR 25, 10:17 PM

a buddy has a knock off quaife in his car, he swears it made a massive difference, he has an LZ9 3900/F23 setup, but does not have the FY1 gears. My car, LX9 3500/F23 w/ FY1 gears has some serious traction issues in 1st/2nd, I'm considering one, but I haven't pulled the trigger yet.

------------------
"I am not what you so glibly call to be a civilized man. I have broken with society for reasons which I alone am able to appreciate. I am therefore not subject to it's stupid laws, and I ask you to never allude to them in my presence again."

I invited Lou Dias to trash me in my own thread, he refused. sorry. if he trashes your thread going after me. I tried.

cam-a-lot

MAR 26, 07:16 AM

Thanks for the reply

Anyone else with experiences or opinions on this? Again, keeping in mind that I won't be auto cross racing/ drag racing the car. I understand the value of LSD for FWD cars in track use, and RWD cars on drag, but with my setup, not quite sure there is a tangible benefit

Looks like the only good option available is the Qiafe unit, which is quite expensive. Anyone here install one on an F23/3800SC or LS car?

[This message has been edited by cam-a-lot (edited 03-26-2023).]

fieroguru

MAR 26, 09:32 AM

For a daily driver car, I wouldn't install one - especially on a higher power Fiero. If you ever find yourself in the rain or on a cold road and give it too much throttle going around a turn, both tires (instead of 1) will break loose and the car will do an uncontrollable 180 in the middle of a public road.

Fieros do not suffer from torque steer of FWD cars, and their differential layout doesn't load one wheel and unload another vs. typical solid axle RWD car under acceleration. Under WOT straight line acceleration I have found that both my rear wheels spin when I over torque them. I can see a LSD being beneficial for a track car where the track is warm, the tires are super sticky, and the available lateral traction exceeds the available drive traction on the inboard tire that is unloaded around a turn - this could limit the amount of throttle/acceleration available as you exit a turn, which the limited slip will help with while also increasing the chance of a spin out if both rear tires break free around a turn.. but that is part of racing... taking the car to its limits w/o going past them..

ericjon262

MAR 26, 04:28 PM

quote

Originally posted by fieroguru:
Fieros do not suffer from torque steer of FWD cars, and their differential layout doesn't load one wheel and unload another vs. typical solid axle RWD car under acceleration. Under WOT straight line acceleration I have found that both my rear wheels spin when I over torque them. I can see a LSD being beneficial for a track car where the track is warm, the tires are super sticky, and the available lateral traction exceeds the available drive traction on the inboard tire that is unloaded around a turn - this could limit the amount of throttle/acceleration available as you exit a turn, which the limited slip will help with while also increasing the chance of a spin out if both rear tires break free around a turn.. but that is part of racing... taking the car to its limits w/o going past them..

yeah, that's one of the big holdups on me getting one, as far as I can tell, I'm not losing traction because of the differential, I'm losing it because of tires, and boost, I'm hitting 9 PSI very shortly after banging 2nd, and it's coming on HARD.I'll be adjusting boost control to help aid in traction,

pmbrunelle

MAR 26, 05:57 PM

When I floor the gas pedal in 1st gear in my Fiero, it leaves two black stripes, so I conclude that there is no asymmetry.

My truck has a clutch-type LSD, and it's sometimes a little bit dicey. On asphalt covered with uneven snow/ice patches, under throttle, the rear end will step out when one tire gets traction.

I don't think I would want a LSD on my Fiero unless I took driving lessons and upped my driving skill.

Frenchrafe

MAR 27, 02:32 AM

As Fieroguru said above, the Fiero doesn't have many problems with an open diff.
And I agree that in wet weather you'll be in more trouble than it's worth with the big risk of spinning out!
I track (circuit and drag race) my Fiero and I've never had traction issues appart from the stickiness, or lack of, with my tyres.
I lay down two solid black lines when I accelerate!!

I've used limited slip differentials in previous cars like my '77 Trans AM (very tail happy always drifting!) and my '85 Renault 5 Alpine turbo (really difficult to make the turns at high speed!)
They needed it. The Fiero does not.

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"Turbo Slug" - '87 Fiero GT. 3800 turbo. - The fastest Fiero in France!
https://youtu.be/c4Cu7_2OgYc
https://www.youtube.com/cha...1wZvWQlkYxTjivW_0XNg

[This message has been edited by Frenchrafe (edited 03-27-2023).]

cam-a-lot

MAR 27, 08:41 PM

Thanks everyone for your advice and opinions. I won't bother with the LSD