Lowering a ZR-1 questions...

[Meanmyz]

I would like to lower a 1995 ZR-1 about 1 inch from the stock height. As you know our cars ride quite high in stock form.

- I do like the supple ride that the stock car provides but know there is some room for a firmer ride that I would put up with.

- I am not a hard core racer, but I do enjoy road racing events like SORC in Nebraska and BBORR in Texas.

It seems that there are as many "cons" to lowering as "pros". I don't want to decrease the ride quality or handling characteristics that Corvette engineers spent countless hours trying to perfect.

The problem:
- Lowering kit - Some research suggests that the cheap lowering kits (wedges for the front) actually decrease the performance of your suspension because in cutting off the leaf spring rubber bumpers, you actually "un-tension" the leaf spring, getting an even more bouncy soft ride. Is this true?

- Coilovers - I have read articles by Hib Halverson on this subject and he is not a fan of coilovers for the reason that these reduce suspension travel, which is the gold standard of ride quality. There are also full discussions on how the leaf spring also acts as a sway bar and coilovers can be a small can of worms unless you really understand them. Some guys on this site have also taken them back off because they didn't like them.

- This car does get driven at high speed and I plan on taking it to BBORR where you are running at high speed for 118 miles. Will coilovers or a lowering kit put shafts and suspension pieces at angles that are detrimental?

What about lowering with the wedge kit and doing Moracca valving? I have come across forum threads where guys said that unless you are a racer, Moracca valving is pretty stiff for the street....?

The car sits quite high and the front spoiler must be 4+ inches off of the ground. Is there a way to "have your cake and eat it too" with lowering a ZR-1? Thanks for any replies from guys that know.

[Meanmyz]

Probably the biggest question I have concerns the cheap lowering kits.

The vendors selling these kits advertise a handling improvement. However, I came across someone saying this "un-tensions" the spring for handling loss.

Who is right?

In the end maybe it is best to accept it for what it is and leave it alone, but I thought I would ask.

[secondchance]

Probably the biggest question I have concerns the cheap lowering kits.

The vendors selling these kits advertise a handling improvement. However, I came across someone saying this "un-tensions" the spring for handling loss.

Who is right?

In the end maybe it is best to accept it for what it is and leave it alone, but I thought I would ask.

Those rubber blocks with steel caps on top has nothing to do with tensioning. I don’t know where this statement comes from. As for the improved handling, lowering the car lowers the center of gravity resulting in reduced lean in turns.

[Gunny]

I would like to lower a 1995 ZR-1 about 1 inch from the stock height. As you know our cars ride quite high in stock form.

- I do like the supple ride that the stock car provides but know there is some room for a firmer ride that I would put up with.

- I am not a hard core racer, but I do enjoy road racing events like SORC in Nebraska and BBORR in Texas.

It seems that there are as many "cons" to lowering as "pros". I don't want to decrease the ride quality or handling characteristics that Corvette engineers spent countless hours trying to perfect.

The problem:
- Lowering kit - Some research suggests that the cheap lowering kits (wedges for the front) actually decrease the performance of your suspension because in cutting off the leaf spring rubber bumpers, you actually "un-tension" the leaf spring, getting an even more bouncy soft ride. Is this true?

- Coilovers - I have read articles by Hib Halverson on this subject and he is not a fan of coilovers for the reason that these reduce suspension travel, which is the gold standard of ride quality. There are also full discussions on how the leaf spring also acts as a sway bar and coilovers can be a small can of worms unless you really understand them. Some guys on this site have also taken them back off because they didn't like them.

- This car does get driven at high speed and I plan on taking it to BBORR where you are running at high speed for 118 miles. Will coilovers or a lowering kit put shafts and suspension pieces at angles that are detrimental?

What about lowering with the wedge kit and doing Moracca valving? I have come across forum threads where guys said that unless you are a racer, Moracca valving is pretty stiff for the street....?

The car sits quite high and the front spoiler must be 4+ inches off of the ground. Is there a way to "have your cake and eat it too" with lowering a ZR-1? Thanks for any replies from guys that know.

Short answer: been there, done that - liked the results

More detailed answer: I owned a 94 LT1 coupe before acquiring the 90 ZR-1. I lowered the 94 (front & rear). The process is fairly straightforward, but not necessarily a quick & easy process (referring to the front).

I got a set of wedges for the front spring, removed the spring, made the alteration, and reinstalled the front spring. This dropped the front at least 2", possibly 3". Removing the front spring was a b***h and, without proper tools, was probably not all that safe. If you have a lift and other tools the job would be easier, but I did it in my garage using jack stands, floor jack, etc. and would NOT do that ever again ... at least not that way. The rear is much easier - find grade 8 bolts that are at least 2" longer than stock. IMPORTANT: I recommend that you cross drill the ends of each of these bolts and install a cotter pin to prevent the nut from working itself off. It is possible for the nyloc nuts (or other safety nut) can work itself off with potentially disastrous outcome. Anyway, once I did this the handling on the track (street, too) improved noticeably and I really liked the way the car looked. Here's a PHOTO (https://www.zrwon.com/garage/1994/slides/IMG_1198.html). and ANOTHER (https://www.zrwon.com/garage/1994/slides/IMG_1195.html).

I wanted to lower the ZR-1 but ultimately decided not to ... the front was tough for me to do and I had gotten older and decided I didn't wish to take the safety risk. I'm fairly certain I have the wedge kit that I bought for the Z ... PM me if you're interested. You will have to find a nuts/bolts store that specializes in the unusual in order to find the longer bolts ... readily available until you try finding the grade 8 hardness. Home Depot & Lowes won't have them.

Coil Overs might be worth looking at but I have no knowledge of "how to" or cost involved. Perhaps someone else will chime in.

[32valvesftw]

Im lowered about an inch with a Guldstrand lowering kit and rear suspension. The car was that way when I bought it. I ASSUME they did not use wedges but may have. I have not compared the arrangement to a stock Z so I am not sure. The rear has longer bolts, but most of the other suspension components are also different. The cars handles really well, it feels like it pivots around the seat. It retains the FX3 shocks, and frankly its too soft for my tastes on the lowest (Touring) setting. Lowered looks better too IMHO.
The negatives, depending on where you live and the quality of roads, you may scrape the air dam. I see now that you are in Minnesota but you probably don't drive it in snow, if you do it will plow. I have also hit my headers a few times on big bumps. At the moment I have the outer parts of the air dam removed, the center section is still in place.

[Z51JEFF]

https://i.postimg.cc/63Hp4mV6/E313-D677-BD0-D-44-F1-AD1-C-B050-A4609631.jpg (https://postimg.cc/ft9N65g1)
I lowered mine using an adjustable front spring from VP&S,not sure they make the spring anymore. I’ve cut the front spoiler to keep from smacking it on anything. My car is very low,most won’t go this low but that how I like it. I don’t do speed bumps and steep driveways are a challenge to keep the spoiler off the ground.

[RussMcB]

I lowered my rear a little, mainly because I had a visual big gap between the tires and the fender arches, especially on one side (which I hear isn't unusual for our cars).

For me (my car, my wheels/tires, my use), I would not want to lower the front. As it is, the front tires slightly touch the inner fenders during hard cornering, and I don't have the same visual gap as I had in the rear.

And, as Gunny points out above, lowering the rear with the longer bolts is much easier than lowering the front (or converting to coil-overs).

I'm very happy with how my mostly stock ZR-1 handles on the track. Very predictable, low and acceptable body roll. I think we really benefited from the many showroom stock racing miles done in C4 Corvettes.

[Meanmyz]

Thanks guys for all of the responses.

Yun, thanks for clarifying the tension thing. It is what I read on someone's Corvette Forum posting.

It is good to have all of your thoughts/experiences. Vette Brakes & Products is no more Jeff, their adjustable spring would have been the hot ticket.

Thanks again fellas!

[Young1]

This thread made me think about this. When the stock suspension is fully compressed, what is the distance of the lowest point of the tub to the pavement? It seems imperative to know this to determine what is a safe amount to lower. Imagine a dip in the road at 140 mph. It could be possible to lose traction on all four at the same time while slamming the tub to the pavement. Any one know the measurement?

[32valvZ]

I had my 92 Z lowered in the rear only.... it really helped the overall look of the car which is what I was intending... ride characteristics were a little more harsh, but tolerable. That said, I havent touched the 90's ride height so far... its just not that big a deal to me anymore I guess... I must be getting old. :p

[DRM500RUBYZR-1]

So what's the big deal?

Lowering?

I lower mine every time I get into it.................................

Marty

[BigJohn]

Scrape!

[-=Jeff=-]

So what's the big deal?

Lowering?

I lower mine every time I get into it.................................

Marty

LOL..

[Meanmyz]

This thread made me think about this. When the stock suspension is fully compressed, what is the distance of the lowest point of the tub to the pavement? It seems imperative to know this to determine what is a safe amount to lower. Imagine a dip in the road at 140 mph. It could be possible to lose traction on all four at the same time while slamming the tub to the pavement. Any one know the measurement?

Good point Steve. However, I don't think that lowering the car would affect where the bump stops are. You are just taking up an inch (if you lower it that much) of the suspension travel.

Something to think about though because my tech speed at SORC is 140 mph and there are about three stretches on a "not so smooth" road where I am hitting that.

Sometimes I think "just leave the suspension alone". ZR-1's ride a little high which is a trademark of the car and on my stock Z's, I wouldn't think about lowering. It's just that you know....mod "itis"... I added a little power, now why don't lower it a little, and on and on.

[Hib Halverson]

Unless you are a track rat, lowering the car a full inch all around will come with some compromises.

Trying to go fast on windy roads which have a lot of bumps, heaves and undulations, you're going to be tagging the bump stops.

When that happens, the wheel rates go sky high and the changing wheel rates make the car very difficult to drive at the limit.

Also, just cruising on the highway, if the road is rough or has a lot of dips, swales and heaves, the ride gets really choppy because your tagging the bump stops sometimes in the tour mode.

[Meanmyz]

Thanks Hib. It is this kind of feedback that I welcome.

At SORC a few weeks ago, there are a few long stretches where I was reveling in my legal "authorization" to be going 140 mph. If you had ever raced there on the road we run, you would know it is a recipe of "bumps, heaves, and undulations"...seriously! It only gets relatively smooth at speed!

I will tip my hat to the Scott Allman, John Heinricy, and others of the C4's past and think I will leave my ride height alone.

Moracca valving with a lowered height would probably work, but I kind of like my quality.

Hib, in doing my research, I was wishing I could ask you if you had lowered Barney. The one picture I always see of you negotiating a curve makes it look like it is lowered. Your suspension was probably just "compressed"!

Thanks.

[Young1]

Practically with two passengers, a yorkie and luggage for a week and carving the mountains the safest is to have all the suspension travel you can get. Best to leave the lowering for the show and the track.