Is anybody running a Phantom grip unit in their transmission? Thoughts? Recommendations? I know the welded diff will require more finesse from the driver but that is what I'm used to as go-karting is my pass time.

Thanks

Rei Moloon

My understanding is karts use frame twist (if you are doing it right) to take some weight off the inside wheel to help the kart turn.

A welded diff on the street would be a very bad idea. You just can't go fast enough around typical street corners to make the hopping, skipping, leaving patches of tires at every turn go away. Not to mention trying to park a car in a typical parking lot will always be a challenge. You need some slip on the street. On the track they add some braking stability from very high speed and earlier power apply points in critical speed turns. Two things you don't need on the street.

quote Originally posted by SCCAFiero: My understanding is karts use frame twist (if you are doing it right) to take some weight off the inside wheel to help the kart turn. A welded diff on the street would be a very bad idea. You just can't go fast enough around typical street corners to make the hopping, skipping, leaving patches of tires at every turn go away. Not to mention trying to park a car in a typical parking lot will always be a challenge. You need some slip on the street. On the track they add some braking stability from very high speed and earlier power apply points in critical speed turns. Two things you don't need on the street.

Thank you SCCAFiero! This is primarily a track day car. I only take it out on the streets to test changes I've made and to enjoy the a sunny day on the winding roads of North Carolina. The only traffic area I've taken it is to a car show 5 miles from my home. Karts have a solid axle and I got used to using the rear traction to turn the kart quicker tight turn. I can pretty much apply everything from the kart driving style to the Fiero and it I'm impressed but it's lacking exiting traction and rear brake bias . I believe the welded diff and better rear brake bias will give my Fiero that kart-like handling I'm used to.

I don't think a welded diff would last too long for you. I used to race carts as well and when cornering in a cart you're pretty much three wheeling it around the turns lifting or at least taking most of the weight off the inside rear tire. The track width of a cart is also very narrow which makes getting away with a locked rear alot easier to deal with, whereas a Fiero's much wider track will increase those twisting loads on a locked diff very substantially in comparison. For a track only car a welded diff might survive, but as SCCA said the chassis are completely different between a Fiero and a cart. How much power are you going to have in your Fiero? If you're not going to be making substantially more [ 2x +] than a stock Fiero, you're not going to be able to take advantage of the gains a locked diff will give you. I would opt for the lsd, it will be much easier on parts and you'll get most if not all of the benefits you're looking for.

Just my .02 cents. Good luck with whatever you decide and have fun with it

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BLACKKER 1988 CHOPTOP V8

Local club http://www.foxvalleyfieros.webs.com/
Facebook club page http://www.facebook.com/gro...?gid=141412865904993
N.I.F.E. member #461 Chris M http://www.fierofocus.com/

quote Originally posted by av8fiero: I don't think a welded diff would last too long for you. I used to race carts as well and when cornering in a cart you're pretty much three wheeling it around the turns lifting or at least taking most of the weight off the inside rear tire. The track width of a cart is also very narrow which makes getting away with a locked rear alot easier to deal with, whereas a Fiero's much wider track will increase those twisting loads on a locked diff very substantially in comparison. For a track only car a welded diff might survive, but as SCCA said the chassis are completely different between a Fiero and a cart. How much power are you going to have in your Fiero? If you're not going to be making substantially more [ 2x +] than a stock Fiero, you're not going to be able to take advantage of the gains a locked diff will give you. I would opt for the lsd, it will be much easier on parts and you'll get most if not all of the benefits you're looking for. Just my .02 cents. Good luck with whatever you decide and have fun with it

I'm just tire of the inside wheel loosing grip! I can hear the engine and look at my tach go from 3000 to 6000rpm in a blink of an eye exiting a tight turn and the car lags and when I straighten the steering wheel it'll grab again. It even does it sometimes when I'm steadily on a hard load sweeping turn. I'll keep researching on the Phantom Grip. But thank you for taking the time to give me your thoughts on this subject!

Thank you again

I tried the Phantom Grip in a 7.5 gm 10 bolt.. It didn't last very long. It was not very strong from the get go.
The name suits it very will.Phantom = Illusion, a distortion of the senses. Backed up with real HP.. It shows
its self to a Phantom.. It works as a weak posi I guess..

I have ran welded diff in my jeep. Dana 44. It would twist the axles sooner or later. But then thats 33in tires I would think A welded diff
in a fiero would not last very long. Do they not make a locker of some kind?

I really like drive spooled diff cars. Steering with the rear tires
Most drivers can't drive a car if the rear wheels don't follow the front.

ep lsd is a better option.

http://www.engineered.net/eplsd.htm Sweeeet... !!!!!

quote Originally posted by billpapps: http://www.engineered.net/eplsd.htm Sweeeet... !!!!!

Thanks, I'll give them a call next week!

A open diff will be all you need for peak traction in the rear. I have yet to find the limits of an open diff in a fiero, as with independent suspension and in most cases limited horsepower... you are gaining nothing from a friction LSD, and probably next to nothing with a torque biasing one.

quote Originally posted by La fiera: I'm just tire of the inside wheel loosing grip! I can hear the engine and look at my tach go from 3000 to 6000rpm in a blink of an eye exiting a tight turn and the car lags and when I straighten the steering wheel it'll grab again. It even does it sometimes when I'm steadily on a hard load sweeping turn. I'll keep researching on the Phantom Grip. But thank you for taking the time to give me your thoughts on this subject! Thank you again

I've done a welded diff. It was in an '88 Camaro, but here's the deal: It sucks! I had to order the largest aftermarket rear anti-roll bar on earth. Once I got it in, it would then lift the inside rear tire when cornering hard, and help that tire to spin, while the outer tire did the thrusting. Too much pedal, of course, resulted in instant, extreme oversteer.
In a Fiero, you'll have to lift for every turn, or face serious understeer.
But trying to maneuver in parking lots, with cops nearby, was NOT happening. Chirp, chirp, chirp.
Never mind when stupid teens pointed and laughed, they didn't know any better.
And on sticky tires, you're always risking a broken axle in every tight turn.
Go ahead and try the Engineered if you like, but for a true LSD, go F23 and add the OBX.

quote Originally posted by Isolde: I've done a welded diff. It was in an '88 Camaro, but here's the deal: It sucks! I had to order the largest aftermarket rear anti-roll bar on earth. Once I got it in, it would then lift the inside rear tire when cornering hard, and help that tire to spin, while the outer tire did the thrusting. Too much pedal, of course, resulted in instant, extreme oversteer. In a Fiero, you'll have to lift for every turn, or face serious understeer.

With an open diff (or a LSD which isn't locking enough) you'll get inside rear wheelspin. This is generally pretty benign. The car will just feel like something is holding you back so you can't get a good exit. You should be able to feel the inside rear spinning and hear the engine revs come up without any acceleration to correspond. You'll often get a slower, long duration loose condition in this situation. And this is my situation now.

When the diff is locked (or the LSD is locked enough) you get wheelspin from both rear tires at the same time. This will sidestep the rear of the car because you're giving up pretty much all of your rear lateral grip. Assuming your driving is anything reasonable, it isn't quite as abrupt or alarming as it might sound. After both wheels are spinning, you just start to crab out to the exit of the corner. I suppose if you had both tire spinning and you went full throttle you might spin the car or have a big slide, but generally this isn't how people drive. That is when your butt sensor tells your brain you have to adjust your foot control on the throttle and have an understanding of the tunability of your suspension.

You can compensate for the understeer by tightening the rear and loosening the front swaybars to balance the car. And that is the other thing on my list, the HHP swaybars. Also driver has to drive with more finesse to keep the car under control. Mark Donohue, the 70's F1, Can AM, Indy car driver used lock diffs in everything he drove. Mr David Hobbs, comentator of "The NASCAR Channel" I mean SPEED CHANNEL said he would never drive a locked diff car and criticized Donohue for that preference, Donohue just simply told him he didn't have the cajunas as a driver.

[QUOTE]Assuming your driving is anything reasonable, it isn't quite as abrupt or alarming as it might sound.[QUOTE]

It's not just your driving. Many other factors are at play. The tires themselves, the tire width versus rim width, the engine response, and if applicable, the way the turbo boost comes on.

I sincerely thank you all for your personal input, advice and past experiences but like always I have the last word because it is my Fiero
My plan is to take my car to a 2 day track event and learn how it behaves with the upgrades at that time. Then will take it to another 2 day track event with the welded diff and adjust the set up and driving style accordingly and then compare notes. Like someone said: "You have failed just by not trying"

quote Originally posted by La fiera: I sincerely thank you all for your personal input, advice and past experiences but like always I have the last word because it is my Fiero My plan is to take my car to a 2 day track event and learn how it behaves with the upgrades at that time. Then will take it to another 2 day track event with the welded diff and adjust the set up and driving style accordingly and then compare notes. Like someone said: "You have failed just by not trying"

Whoever said that has failed by not jumping into the volcano while it was spewing red hot lava. Sometimes, it's best to believe others when they all have the same results from trying the same thing.
It is your car, and you probably can cope, but long term, I predict disillusionment.
By the way, if you cause a crash on the street, and the welded diff played any part, and that mod is discovered, then you're liable, plus your insurance doesn't have to pay out.

[This message has been edited by Isolde (edited 12-25-2010).]

quote Originally posted by La fiera: I'm just tire of the inside wheel loosing grip! I can hear the engine and look at my tach go from 3000 to 6000rpm in a blink of an eye exiting a tight turn and the car lags and when I straighten the steering wheel it'll grab again. It even does it sometimes when I'm steadily on a hard load sweeping turn. I'll keep researching on the Phantom Grip. But thank you for taking the time to give me your thoughts on this subject! Thank you again

I have no idea what your setup is, or how tight of turns you are making, but it sounds like you have a bigger suspension problem than a power application problem. I noticed some slip on mine before it was welded but that was rare and certainly not a 3000 RPM increase. The only times I ever had an significant increase was when my clutch was crapping out and even then it was not that big.

The few other track only Fiero guys I have talked to are/were running the stock open differential with no complaints. I am debating on taking it out now that my suspension is even better than it was before I welded the diff.

quote Originally posted by Isolde: Whoever said that has failed by not jumping into the volcano while it was spewing red hot lava. Sometimes, it's best to believe others when they all have the same results from trying the same thing. It is your car, and you probably can cope, but long term, I predict disillusionment. By the way, if you cause a crash on the street, and the welded diff played any part, and that mod is discovered, then you're liable, plus your insurance doesn't have to pay out.

Thanks for you concern Isolde and I'm very aware of the insurance issue you mentioned and I bet everybody who has an LS1, 3.8SC, SBC, VR6, 4.9, welded diff or any other mod in their Fiero are aware of that. That is why this is not my daily driver and that is why I go to track day events. When I do drive it on the streets I'm very aware of my car's limitations which I've never try to meet or exceed on the streets. As far as your prediction you won't know until I try it and If I don't like it I promise you you'll be the 1st to know.

quote Originally posted by SCCAFiero: I have no idea what your setup is, or how tight of turns you are making, but it sounds like you have a bigger suspension problem than a power application problem. I noticed some slip on mine before it was welded but that was rare and certainly not a 3000 RPM increase. The only times I ever had an significant increase was when my clutch was crapping out and even then it was not that big. The few other track only Fiero guys I have talked to are/were running the stock open differential with no complaints. I am debating on taking it out now that my suspension is even better than it was before I welded the diff.

I believe you have #400lbs all around and Konis? Well I have #350 all around and KYB's, stock front swaybar and TFS rear swaybar. The shocks are temporary. When I do my HHP swaybar upgrade I'll also upgrade to koni's and after that I'll decide if I still need the welded diff. The wheel spin usually happens in 1st or 2 and part throttle coming out of a tight turn and started happening after I installed the upgraded 2.8 with a little more power. In this engine peak torque(166 @ wheel)l is at 4400 and it has a flat hp(155 @ wheel) line from 5200 to 6000 with an 11.5 AFR. A little rich but that was the only dyno run I did just to have an idea where I was standing and then tune accordingly. As you can see, the extra hp and torque combined with their relocation at a higher rpm range can be contributors to the problem.
But tell me about your experience with the welded diff! From a scale from 1 to 10 what number would you give it?

I am still debating on its true value so really can't put a number on it. I had to run the extra external CV bearings on the differential as I was spitting out the passenger side axle after a few laps before I added them. The tripot would simply back out of the diff about 1 inch or so and start leaking.

One of the biggest reasons I want to remove it, is due to the heavy under steer or push it causes, especially in tight turns. Some of that is due to my weight balance (42F/58R or 44F/56R IIRC). I have gotten comfortable enough to goose the throttle in turns a bit to break the rear loose to get it to turn easier. Of course, that also adds a whole different element to driving it and I have goosed it just a bit too much on a rare occasion, causing unwanted excitement for those behind me. In the rain, it can be a challenge.

I like the fact that it added a level of stability under hard, threshold braking from 100mph plus. The car always had a little twist or upset when applying the brakes at high speed. The welded diff seemed to cure that, which means I may have a minor imbalance in the rear calipers or something else was going on. The type of thing that is not easily found, but really gets your attention. Maybe compressional braking (from 7k rpm) and reverse torque steer (for lack of a better name) from unequal length shafts, type stuff. I currently run 10:1 compression. All the parts are in good condition back there.

I removed the Koni's from the back and put 300# coil overs on the back with regular Monroe struts. There is so little suspension travel (due to lowered ride height) that the weaker struts don't seem to be as important as the spring rate at this point. I am playing a bit with the ride height to address the positive camber in turns problem on lowered 88s. The front springs are stock 88 cut units with Bilstein shocks. I do have big sway bars front and rear and the cage also stiffens the car up quite a bit. I have also played with different tire size combination's and types. While I can fit bigger tires on the front (to help with the under steer), the car seems to like the same size tire all the way around 225 45 or 50, 15. I am limited to a 15 inch wheel.

Since my co-driver and I are within about .02 seconds of each others lap times, we are both coming to the conclusion we need a different, front engine/rear drive platform to work with. This was a good, cheap car to learn to race with but we are fast approaching its limits, within the rulebook.

I also never use first gear on track once the car is moving. I will use second occasionally, due to the non race designed Getrag that has such a big RPM drop between gears. Those must be some very tight turns if you need to shift down to first which means a locked diff will probably be even worse for you as it simply will not make tight turns with both wheels wanting to go straight all the time. The amount of time the wheel is lightly loaded is a lot less than the total time in the turn.

The jury is still out on its value. Although a verdict may never be reached. I will not mess with it until I have to open the tranny for some other reason.

quote Originally posted by SCCAFiero: I am still debating on its true value so really can't put a number on it. I had to run the extra external CV bearings on the differential as I was spitting out the passenger side axle after a few laps before I added them. The tripot would simply back out of the diff about 1 inch or so and start leaking. One of the biggest reasons I want to remove it, is due to the heavy under steer or push it causes, especially in tight turns. Some of that is due to my weight balance (42F/58R or 44F/56R IIRC). I have gotten comfortable enough to goose the throttle in turns a bit to break the rear loose to get it to turn easier. Of course, that also adds a whole different element to driving it and I have goosed it just a bit too much on a rare occasion, causing unwanted excitement for those behind me. In the rain, it can be a challenge. I like the fact that it added a level of stability under hard, threshold braking from 100mph plus. The car always had a little twist or upset when applying the brakes at high speed. The welded diff seemed to cure that, which means I may have a minor imbalance in the rear calipers or something else was going on. The type of thing that is not easily found, but really gets your attention. Maybe compressional braking (from 7k rpm) and reverse torque steer (for lack of a better name) from unequal length shafts, type stuff. I currently run 10:1 compression. All the parts are in good condition back there. I removed the Koni's from the back and put 300# coil overs on the back with regular Monroe struts. There is so little suspension travel (due to lowered ride height) that the weaker struts don't seem to be as important as the spring rate at this point. I am playing a bit with the ride height to address the positive camber in turns problem on lowered 88s. The front springs are stock 88 cut units with Bilstein shocks. I do have big sway bars front and rear and the cage also stiffens the car up quite a bit. I have also played with different tire size combination's and types. While I can fit bigger tires on the front (to help with the under steer), the car seems to like the same size tire all the way around 225 45 or 50, 15. I am limited to a 15 inch wheel. Since my co-driver and I are within about .02 seconds of each others lap times, we are both coming to the conclusion we need a different, front engine/rear drive platform to work with. This was a good, cheap car to learn to race with but we are fast approaching its limits, within the rulebook. I also never use first gear on track once the car is moving. I will use second occasionally, due to the non race designed Getrag that has such a big RPM drop between gears. Those must be some very tight turns if you need to shift down to first which means a locked diff will probably be even worse for you as it simply will not make tight turns with both wheels wanting to go straight all the time. The amount of time the wheel is lightly loaded is a lot less than the total time in the turn. The jury is still out on its value. Although a verdict may never be reached. I will not mess with it until I have to open the tranny for some other reason.

The fact that you have experience on a Fiero with the modification I've been trying to get valid data from and in the scenario that I'm intending to use my Fiero on, your input definitely plays a very important is role on my decision on the welded diff. The pushy nature of the Fiero is one of the aspects that I had to change because I prefer more oversteer. And I had a suspicion that the understeer could be worse with a welded diff, and you have verified that for me. That is why I left the stock front sway bar in the front and installed the TFS swaybar in the rear. I have #350 all around but I need to get #400 for the rear to stiffen it more to cure some of the understeer, to minimize weight transfer to the back on acceleration and to keep that weight in the front for more front end bite. Well, once you take it out and if I haven't done mine, I can probably buy yours.
Thank you very much once again for taking the time to help me in this matter!

Rei Moloon

Have you checked into www.GR8GRIP.com That's what I have in my 4t60, no complaints.

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85 GT 3.4
14.9 @ 90 1.9 60' Old TH125/3.06
Unknown New 4T60/3.42

[This message has been edited by Lilchief (edited 12-26-2010).]

quote Originally posted by Lilchief: Have you checked into www.GR8GRIP.com That's what I have in my 4t60, no complaints.

Thanks dude! I sent a request just now!

quote Originally posted by Lilchief: Have you checked into www.GR8GRIP.com That's what I have in my 4t60, no complaints.

i second that... i have a phantom grip, and it is OK, but honestly, it lacks real locking power when you need it, and makes the behavior of the rear end unpredictable going around turns. the gr8grip from Bud Aldeman is a much better product. you send Bud the diff, and he sends it back to you with the locker installed... real simple. He guarantees his work. the Gr8Grip has four-wall tension, not just two-wall like the phantom grip does