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So I will first start by recognizing that most will doubt what is presented here so I will attach links to some videos from Huibert Mees. He is a renowned suspension engineer, who has done chassis designs for Ford, Tesla & others. I refer back to my earlier post. Most think they know suspension, they think springs, struts, sway bars, (but never think of link ends) & maybe a few other things! And as such think they understand how to build a suspension. If the body rolls it must be springs or CG! So the first order of business; they lower the car’s CG by using a shorter spring! Terrible idea! Why? Even an inch or two down impacts the roll center negatively, while reducing the suspension travel! I am not comparing myself to Huibert Mees, but I have designed suspensions among many other mechanical devices for more than 50 years & have many patents. So I’m trying to garner accolades. There are so many things to look at with a suspension, but if I pick just one thing to affect cornering & more specifically high speed cornering, it would be sway bars & their end link! Yet many ignore sway bars as a remedy. Even more so, most never consider their relative size vs end link size! If, I simply said to you, have you ever heard of Archimedes & his statement of "Give me a lever long enough and a fulcrum on which to place it, and I shall move the world." You most likely would say yes! Well to a degree this is your sway bar & end links! Do you honestly think a bar, aka lever, 4 feet or longer & ¾” or more in diameter; in some cases as much as 1 5/16”; be effectively applied by a secondary lever that is more than 3x smaller!? In some cases like the solid aftermarket front bar of the W-body ll more than 4x smaller. If you did the section modulus of the two you would find the numbers even more staggering! Amanita, without seeing your setup I would be guessing, but by your pictures several things appear to be part of the cause, but all point possibly to two issues. The sway bar & weight distribution. It has been many years since I have worked on one of the first gen W-bodies. So please correct me where I am wrong. Doesn’t the front bar end point attach into a u bracket & rubber bushing? Similar to how the bar attaches to both sides of the frame? If so, the bar as the rectification point! I can explain how. The second is the weight distribution. These cars, as most should know, have a horrible weight distribution. Again there are ways to affect this if you want to put in the work. Last the rear leaf. This can be improved, but it will take work & if you can’t do that work I doubt it is worth it to you to pay to have it done. Last I will attach some pictures, sketches & links that may explain things better, especially the jacking force.

My suggestion to you is to not throw parts at the issue, get a proper scanner on the engine, do a live readout & note in particular what the a/f display is showing you. A failed o2 sensor will only prevent the fuel system from going into closed loop. If the sensor HAD failed then something upstream caused it to. A check engine light will also light up. A bad map will completely throw off the ECM;s ability to configure a proper air/fuel ratio, that will be seen on a scanner as well. Another small item to look at is the wiring harness condition to the engine temp sensor, if it's faulty then that sensor cannot send the proper signal to the ECM to configure A/F ratio due to inaccurate information on the engine actual temp. That will be seen on a scanner as well. The 3 vital sensors needed for the ECM to calculate proper A/F ratio when the engine starts are the MAP, IAT, ENG TEMP.

Hi again. 90 old C/S 3.1. Really bad idle. I replaced the o2 sensor and iacv. After installing the o2 it ran pretty good and then it didn’t. Back to rough idle. Any thoughts on what the issue could be? I’ve heard of bad pcv/ map sensor/ coil pack. The erg is not gummed up. However I just had my battery tested and came back bad. The car starts fine but they said it was bad. I’m not sure if that has something to do with it. Any ideas. Thanks.

Thanks for the tip.

Hi, I’ve been experiencing a voltage drop/ surge only when in gear and at idle. I just put in a new 02 sensor and a iacv. And the alternator seems to be charging the battery at 14.2.the car has the 3.1L thanks for any advice!

Will, the first thing I would say is looking at your pictures the car is delivering a lot of jacking force! This is often an issue with Macpherson strut suspension. I’m pressed for time at the moment, but I will answer your post more thoroughly hopefully tomorrow or possibly Saturday. There are a few things that you can do with the first W-bodies & I have so good things you can do for the W-body ll.

I've probably put my Grand Prix through the ringer more in the past decade than anyone else on this forum and, at least for first gen cars, I feel the springs are the weakest link for how they handle. My car has the sportier FE3 suspension and the amount of body roll is still really high. I have a few pictures of it during track days while in a corner and while it doesn't look that bad I can say that you really do feel all the weight being thrown to the outside of the car. Braking is similar, you feel all the weight getting transferred to the front wheels during an aggressive stop and I've had the back end slide out from behind me a few times because of it. I think the best way to improve the handling for these cars is stiffer springs and better tires, but good luck finding a shop that will fabricate a new monoleaf for you. This isn't nearly as much of a problem with second gen Ws since those actually have some aftermarket options, but I do have a '98 Grand Prix and still feel like the springs need to be stiffer on those as well. I will also add that I do think dropping the car by an inch or so will help so long as you have camber bolts or some other way to adjust the angle the wheels are sitting at, the center of gravity in these cars isn't that bad but it could be better. Macpherson struts aren't exactly the most adjustable setup, but the tires would really appreciate the weight coming down on them in corners at a better angle.

First let me say that anyone should do as they wish, obviously, with their own car! That said, I believe it’s important for proper information in making decisions that affect not just the performance of such choices, but safety. Most will pass over this as just so much yada yada, but those that understand engineering, physics, the principles of energy & much more may take a moment to read & think about this. Recently there was a mention in a post about the lowering of the W-body’s! It was stated that such a choice was a bad idea & I concurred, but I would leave it there at that time! I would like to address those reasons here! Reasons many people believe lowering a car's unsprung suspension is a good idea & will help a car handle better often comes from others who make assumptions & never do the math, really don’t understand the entire physics involved or know how to do the real work that is required to know what their actual numbers are & never truly put the car to a real test to prove it out! Yes they may take that car around a corner faster or it may corner flatter at the same speed as before & it feels good, but what if they really had to push it? So the first fact, & you can research this yourself, is a double wishbone suspension & a macpherson strut suspension are worlds apart. The first can be infinitely fine tuned. The latter can’t! The first has many components that can be adjusted to affect roll center. The latter does not. With a double wishbone you can change caster, a lot, you can change camber a lot. You can effectively do a combination of movement of both caster & camber forward & out or in or rearward & out or in whichever you chose. With combinations to create many performance effects & these are just two parameters that affect suspension physics. With many double wishbone suspension you can find lowering spindles! This allows changes to the geometry of the lowered suspension with regards to CG while allowing RC to remain unchanged or altered whichever you chose. For the simplistic explanation, this amounts to the car being lowered, but roll center remains the same,with proper adjustments, as does suspension travel! In a Macpherson strut suspension this does not happen. There is no simple way to change caster! Camber you can, but it has limitations compared to a double wishbone. There are no lowering knuckles for Macpherson suspension for obvious reasons! The bearings are so large there is no room to alter the knuckles. As a result, suspension travel is negatively impacted. Roll center changes negatively, in a bad way automatically & you can’t do much to alter it. Then there is this. How many truly know what their roll center is? How many know how to figure it? Better yet, how many of you can do your own wheel alignment? If all you did was put in lowering springs, & as such the car seems to corner better; then the answer to the above is you don’t know! This means if you were ever to be in a situation of needing to maneuver excessively quick, at a higher speed you might find yourself in serious trouble! In finality, suspensions are very complicated. There are over 100 mathematical calculations involved in setting up just a front suspension! Instant center, roll center, center of gravity, jacking force, anti jacking force, etc… to name just a few! In the end you can make an FWD handle! Not just well, but high end sports car well! But, not by lowering the car!

And a few years later and I'm finally building a proper exhaust for it. I bought a universal kit off Amazon and put this together this weekend, along with a couple used Borla mufflers that were given to me. It's louder than I was expecting, but is mostly just too much bass and rumble for my liking. I attribute it to the 3 inch pipe and straight through design of the mufflers. I have since ordered a smaller inline chambered muffler that I'm going to install where the factory cat/ resonator were installed to see if it tones down the deep rumble a bit. Aside from that, does anyone know where I can get new or like new OEM looking exhaust tips for this car or have recommendations for a lookalike? I'd certainly appreciate any suggestions but ideally would like to copy the original style.

I'm sure everyone will have their own opinion here, but if you want to keep a stock sound I would highly suggest a Walker Muffler. I had them on my 3.1l Grand prix and I think they sounded better than the rusted out stock muffler, and restored the original sound. https://www.walkerexhaust.com/ And here is a Youtube video with a Walker Muffler on a Pontiac 6000. To each their own, if you don't like this, there are plenty of other options. I really like Magnaflow mufflers as well and have those on my GTP, and my old 3.4l Cutlass.

Hi everyone. I’m restoring my 90 olds cutlass , the car is all original. Still has stock muffler. But I’m pretty sure it’s on it way out. My question is if there are any mufflers that won’t take away from that 3.1 raspy sound. That exhaust tone is nostalgic.

Thanks for this.

1.5gens are significantly lower offset than 2nd, though.

I knew the make/model, not specific years. the bell housing is different. Google's gay robot doesn't know about the TC. It also thinks it was in a 94 Lumina. Like hell it was.

What I do not like about spacers is that more often than not a simple spacer will not be either hub centric or wheel centric. Ideally one wants both inner & outer to be centric to what the spacer is being used on. The hubs design is to take the vertical shock of bumps in the road, the wheel lugs are there to hold the wheel to the hub.

I'm glad that joke is still funny

I never thought of that, but I do like that 1/4" spacing on the front after parking next to the TGP. It gives the impression those 2G GTP rims are wider like the TGPs and I have to make that match on the rear to make it all look "right".

I thought the same thing, but then I saw the valance is intact so you know it's fine.

Nice car...1st thing you might consider is removing that led light bar right in the centre of the path for the air intake for the a/c condenser & the rad.

Welcome to the site! There is plenty of information to find around here about these cars.

Hi, I have a 92 Chevy Lumina Z34 automatic with the V6 DOHC. It's all stock. I am new to fixing cars and got it a year ago. Any tips or suggestions is appreciated. The current thing I'm working on it wiring and brakes.

This, kids, is why this website is the fucking best when it comes to W-Bodies.

There's a guy in Denver that we used to use a lot that checked mine out that might be worth talking to: Steve's Transmissions and Gears 303-744-7904

Bumping for any more adventures that anyone may have had with the 284. I have about 1000 miles on my LS4/ 284 combo and all seems well. I have two additional 284s in need of different repairs that I could/ would like to combine to make one like-new unit.

Psssst....hint *move the calipers inboard*