I didn't think the cavalier was ever available with LSD. Only ecotec I'm aware of that was available with LSD was the LSJ and LNF, neither of which were in any cavalier.
So the only way to get the GM supplied LSD is to find a F23 from an Ecotech car with that option and then swap the case to mate to the V6 engine? That would probably be more inexpensive than buying the Quaif unit for $1100?
You would need an adapter plate to bolt the F35 up. No idea if axles and such would still fit. I hear the F35 breaking all the time but it might just get abused more than the F23.
Originally posted by KurtAKX: F40 came on the G6 GTP, and some Saab cars w/V6. G6 engine has the Fiero-compatible bellhousing. No LSD.
F40 is still available in some cars, with Ecotec engines; so it's been available with three different bell patterns. ONLY the G6 will fit. (Just to clarify in case someone looks at this thread and buys a newer F40 with the wrong pattern). Also, with at least the Saab version, the XWD cars may have had an LSD in the rear diff, which may add to confusion when searching for an LSD for it. Only LSD for the diff in the F40 itself, is the one from Quaife.
This unit is going in my autocross/track race car. I currently have the Engineered Performance unit in a 282 5 spd that grenaded this past weekend at a track event. The LSD is important here, 160 rear wheel HP has to go somewhere in a 2200# car The winter project is to swap in the F23 and want to make sure I have all my info prior to the tear down. The main reason for the diff is that during hard cornering I was experiencing a lot of wheel spin on the inside, unloaded wheel. The LSD has helped out a lot here in lowering lap times. Many of our AX sites are older parking areas and subsequently very dirty. launching was an issue here too. But ever since the LSD was installed the car has been very competitive and much more fun to drive. We have one more 282 on the shelf without the diff but now may be the time to make this switch.
This unit is going in my autocross/track race car. I currently have the Engineered Performance unit in a 282 5 spd that grenaded this past weekend at a track event.
What exactly "grenaded"?
quote
Originally posted by mcguiver3: The LSD is important here, 160 rear wheel HP has to go somewhere in a 2200# car The winter project is to swap in the F23 and want to make sure I have all my info prior to the tear down. The main reason for the diff is that during hard cornering I was experiencing a lot of wheel spin on the inside, unloaded wheel.
As has been said, the G85 option was only in the F35 transmission, which was only used with the LSJ/LNF Ecotec engines and was never built with the V6 bellhousing pattern. There are a wide variety of F23's available, so do some research. Most of those transmissions were built for Ecotec applications, so you'll need to do a bellhousing swap to make use of them.
Also, are you running a gigantic rear sway bar?
[This message has been edited by Will (edited 09-23-2014).]
The Engineered Performance LSD spring blocks shattered and sent a piece through the top of the case. This is the second failure we've had with this diff. Another of our race cars (86 SE V6) had the same issue. The rear bar is a custom fabricated adjustable unit I built 3 years ago with great results. The car handles exceptional well with the mods I've made over the years but now it's time to do the trany with something a bit more modern. I have the fabrication skills to mount it and the cables but I don't want to split the transmission due to the lack of special tools and knowledge.
The EP diff has been in this car for 3 years. The first one that blew was in a car for 30 seconds. There was a design flaw in the first generation piece and was redesigned with a thicker mid section. The reason this one went was due to a rear hub failure that locked up the left rear wheel and subsequently the diff took the hit. It breaks at it's mid section and sends the pieces in all directions. I have not dissembled the trany yet but I suspect some internal damage. As for the bar thing. Rear spring rates are 400# coil overs in the rear and 300# coil overs in front (custom built). Front bar is a stock 88 unit and the rear is a stock 88 bar with shortened and adjustable end plates. As I said earlier, the car handles exceptional well and has been a work in progress for the last 10 years. It is very competitive and is very close to being and FTD car occasionally. Having the LSD has brought the car to life and even though some question the logic of having it................. IT WORKS. I have designed and fabricated almost every aspect of the chassis and don't wish to compromise it in any way. Just wan t to upgrade to a more readily available and lower mileage trany and now is the time
On my Formula with stock springs/bars and Konis set full stiff (full stiff rear, one turn from full soft front), the percentage split between pure roll stiffness and jounce/rebound stiffness is significant. The ride is very well damped in jounce/rebound, BUT underdamped in roll such that the car fishtails a little coming out of a drift.
Obviously, going from 150# springs to 400# springs with the stock bar will mean that the percentage split between jounce/rebound and roll stiffness will be much less, so one damper setting will be closer to matching both stiffnesses.
Did you notice any increase in understeer with the EP unit? It has about 80 ftlbs of torque preload, so if it reduces inside rear wheel spin, you're only lacking enough contact loading on the inside rear to amount to 80 ftlbs of axle torque... that's not much. I think you could get your traction back by removing the rear bar and increasing the rear spring rate (will you struts handle stiffer springs?).
It would be an interesting experiment, at any rate. You might solve your problem with $100 worth of springs instead of $1100 worth of Quaife, AND reduce weight by eliminating the rear bar.
There are other threads on that forum about his development of that car for track use. The author also posts on this forum under the same user name.
Also, have you looked into alternate ratios for the 282? There are shorter 2nd, 4th, 5th and final gearsets available, as well as a stronger diff used in the HTOB boxes behind the 3.1 Gen2 V6.
[This message has been edited by Will (edited 09-24-2014).]
Considering I run much more power in a car with much less overall weight and much less weight in the rear... I cant see a lsd helping a fiero in autox.
Im not saying its hurting you particularly but I cant figure out how you are managing to spin the inside tire on a 150hp fiero.l without having serious issues of cornering traction as it is. I know my 210whp turbo miata is alignment sensitive but it still runs an open diff with mild success. From what ive been told by the top 150hp miatas around here.. they have almost no gains upgrading to a lsd on the autox courses in the midwest national level events.
Mjata suspension works differently than Fiero suspension. With the low roll center and high CG over the rear tires, the Fiero is going to see more weight transfer in the rear than a Miata will.
It would be interesting to see how FieroGuru's '88 link relocation brackets could help this guy also.
Also, do Miatas at that level typically run rear bars?
[This message has been edited by Will (edited 09-24-2014).]
Weight transfer isn't body roll. Weight transfer is a function of track width, roll center height, CG (really centroid axis) height and lateral g. At a given lateral g, a car will have the same weight transfer whether it has 100# springs or 1000# springs.
He's said it's neutral as-is, so if he eliminates the bar to improve traction, he's going to have to increase the spring rate.
I didn't think this would but people at odds. For the first 3 years I AX the car it was stock and fun to drive but I realized that it was not the car that was slow it was the driver. Then things started to click and for the next 2 years I knew I had to start somewhere to make the car better as I was getting the hang of things and learning quickly. In 2009 I made the decision to run FP and take advantage of the rules as they pertained to an 88 Fiero. So the car went on a diet, 1550# in the trash to be exact and I started to play with the suspension. Koni single adjustable struts went in the rear and I developed a coil over set up using QA-1 single adjustable units for the front, Experimented with different springs and for the next 4 years sorted things out to what I have now. As I mentioned earlier the EP LSD, while simple in design and concept did make a change for the better and lowered my lap times. There are 3 other Fieros using this device and all perform well. I did want to utilize a true gear type diff (Quaife) but there were none available for the 282. So here we are, I will be doing something this winter and was looking for some basic info on the F23. I think buying the one I found here in CT and ordering the Quaife diff is the solution. I will have other questions as work progresses. Such as is a HTOB spacer needed for the V6 application? Some say yes, some say no. I will keep everyone informed. Any suggestions will be appreciated.
Weight transfer isn't body roll. Weight transfer is a function of track width, roll center height, CG (really centroid axis) height and lateral g. At a given lateral g, a car will have the same weight transfer whether it has 100# springs or 1000# springs.
He's said it's neutral as-is, so if he eliminates the bar to improve traction, he's going to have to increase the spring rate.
I get the idea. There is a real fast (80mph) switchback at the track i run around up here in michigan, and its a bit spooky when i ran it earlier this year with no sway and wussy springs. I was still gripping but it was a bit slow to react to the weight transfer.
Will, Point well noted. wrong choice of words on my part. I apologize. Hope I didn't offend anyone? At 61 years old I get set in my ways I get a little ramped up when I start talking about Autocrossing. Get a bit carried away with things. But it will be ski season here in the east in a month and I should settle down a bit then. Thanks everyone for the input, keep it coming.
I will say the LSD was a good addition to the autox performance of the miata, but really its just a gravy item that you can drive or tire around. I would be curious to know what your gains were adding the swaybar other than getting a bit faster tip in because in an autox track situation I dont see a rear bar doing good in a 88 fiero, but i could be wrong.
Well the rear bar was standard issue on an 88 Formula. As I progressed with the car it started to exhibit a severe understeer condition. Played with tire pressures (R-Comps), shock settings F&R, spring rates, ride height settings, corner weighting. When I stiffened the rear bar the car liked it. Likewise when I added the EP diff it like that too. This season I bought a set of Hancook 214 soft 240/45/17 rear , 225/45/17 front and it really liked those. If not for the hub failure leading to the trany explosion I would not be talking to you guys right now. Now if I could only hit the lottery!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
When you lower the rear of an 88 w/o changing the lateral link pivot locations, you substantially Increase the tendency for the rear to roll as the roll center drops quite a bit more than the CG is lowered.
[shameless plug] If you are running 17" wheels, my lateral link relocation kit helps eliminate this increase in roll by correcting the rear geometry. //www.fiero.nl/forum/Forum4/HTML/060635.html
Increasing rear caster may help with camber gain in the rear as well. You could do that with lateral bar adjustemnts as well.
I would suggest our suggestions here about how to get around the lsd are just as or if not more valuable than helping you find an expensive lsd.
...but there isn't rear caster. (in before Will!)
from Wiki, "The caster angle[1] or castor angle[2] is the angular displacement from the vertical axis of the suspension of a steered wheel in a car, bicycle or other vehicle, measured in the longitudinal direction."
I get the idea. There is a real fast (80mph) switchback at the track i run around up here in michigan, and its a bit spooky when i ran it earlier this year with no sway and wussy springs. I was still gripping but it was a bit slow to react to the weight transfer.
To get from 5 degrees roll one way to 5 degrees the other way, you need to roll fast, which builds up a lot of roll momentum. Dissipating it is taxing to the dampers, so you may end up with roll oscillations (fishtailing).
If your springs limit the car to 2 degrees of body roll each direction, then the car only needs to roll 40% as fast to get from one extreme to the other in the same amount of time. Also, the stiffer springs are going to move the body more quickly anyway...
When you lower the rear of an 88 w/o changing the lateral link pivot locations, you substantially Increase the tendency for the rear to roll as the roll center drops quite a bit more than the CG is lowered.
[shameless plug] If you are running 17" wheels, my lateral link relocation kit helps eliminate this increase in roll by correcting the rear geometry. //www.fiero.nl/forum/Forum4/HTML/060635.html
[/shameless plug]
Series8217, whose threads I linked above, and whose car is gaining notoriety via feature in Grassroots Motorsports and other venues says that the lateral link relocation kits are the best mod he's ever done to the car (or maybe tied with really quick power steering for "best mod" status).
