Ride Height with H&R springs

[Hoyt Clagwell]

Final report (I hope). After looking at the car for a couple of days, I decided I didn't like the lowered look in the back. I don't like that the roundness of the wheel well doesn't match the roundness of the tire. Looks squished to me. The front had already come out close to stock, so I raised the rear back to stock height by putting the stock lower spring pad (with lip removed) underneath the new 10mm pad. ..... So, if my car is a good example, the formula for installing H&R springs and keeping stock height is: FRONT: remove upper spring pad, replace with two 9mm pads ( ) stacked together, keep lower spring pad. REAR: add a 10mm lower spring pad, keep stock upper and lower pads. ...... No alignment issues, no tire-wear issues, but better handling. .......... P.S. I was looking at Texaz3's coupe with just 10mm on the back, it's about the same as mine with 10mm & stock pad together. Go figure! I do have both soft and hard tops, but I wouldn't that would be heavier than a coupe.

Front pads 9mm:

Mfg Part #

31332227901 31-33-2-227-901 31 33 2 227 901 31.33.2.227.901ECS Part #ES#50698Brand
Rear pads 10mm :
Mfg Part #33531136387 33-53-1-136-387 33 53 1 136 387 33.53.1.136.387ECS Part #ES#58755

I said I'd report more after some higher-speed cornering. I did some familiar highway ramps, around 80+ mph. The report is "WOW". A very solid improvement. I remember pushing a 300ZXTT(that had some handling mods) through those same corners, feeling that point where the car doesn't want to go any faster. I can't find that point in this car. It just digs in and holds the line. This car is reaching the point where it can go around a corner faster than I am willing to go.

s
Well, I started with an M, now have H&R springs, Koni shocks, IE subframe bushings, and Conti extreme sport tires. All else is stock, in new or okay condition. That should be it for handling ........... until somebody gives me some new idea .........

Okay, you caught me. One more non-stock item: poly sway bar bushings. And the endlinks are new, stock.

I gathered that you had veered off of your original topic as it was pretty much concluded. If you still had more to say on the subject then please excuse me.
embarrassed.jpg

[pepz]

After reading zellamay's explanation on being able to keep the stock height when using H&R springs, I've decided to use them for their better handling than the OE springs. However, I am starting to see different photos of H&R springs for the Z3. I've always seen the red sports springs for the Z3, but now I see photo's of what looks to be a blue version. Not only is the color different, but if you look closely at the springs they have a different spring configuration to them. I do not know if they are just using an incorrect picture of the springs. Does anyone know if H&R made changes to the springs used for Z3's.

Typical red sports springs

https://www.fcpeuro.com/products/bmw...20group%20%231

Different springs I am starting to find

https://www.pelicanparts.com/catalog...rt-springs.htm

[zellamay]

After reading zellamay's explanation on being able to keep the stock height when using H&R springs, I've decided to use them for their better handling than the OE springs. However, I am starting to see different photos of H&R springs for the Z3. I've always seen the red sports springs for the Z3, but now I see photo's of what looks to be a blue version. Not only is the color different, but if you look closely at the springs they have a different spring configuration to them. I do not know if they are just using an incorrect picture of the springs. Does anyone know if H&R made changes to the springs used for Z3's.

Typical red sports springs

https://www.fcpeuro.com/products/bmw...20group%20%231

Different springs I am starting to find

https://www.pelicanparts.com/catalog...rt-springs.htm

Yes, it's confusing, and H&R is very secretive about thier springs: won't discuss differences or spring rates. I bought #29520 from ECS Tuning for my 98 M Roadster. I looked around quite a bit, and I think that is the right one for Z3s. Your FCP Euro ref is not for Z3s. Your Pelican ref says it's for Z3s, but the blue springs in the picture would not work. Pelican shows both; maybe they would say what the difference is.

[pepz]

Yes, it's confusing, and H&R is very secretive about thier springs: won't discuss differences or spring rates. I bought #29520 from ECS Tuning for my 98 M Roadster. I looked around quite a bit, and I think that is the right one for Z3s. Your FCP Euro ref is not for Z3s. Your Pelican ref says it's for Z3s, but the blue springs in the picture would not work. Pelican shows both; maybe they would say what the difference is.

Ok. I didn't specify on the websites for Z3, I just did a web search and these came up for the Z3. I'll verify H&R's are model #29250....thanks.

[pepz]

I just verified it's #29754-2 for non M Z3. Looks like there are on back order on most sites.

[bluptgm3]

I just verified it's #29754-2 for non M Z3. Looks like there are on back order on most sites.

H&R Spring Applications

BMW Z3 M Roadster H&R 29520


BMW Z3 M Coupé H&R 29520


BMW Z3 non-M Roadster/Coupé 4-cylinder H&R 29754


BMW Z3 non-M Roadster/Coupé 6-cylinder H&R 29754-2

[zellamay]

The question that H&R won't answer: what's the diff between M Roadster springs and Z3 6 cyl springs? They should say what the differences are, so that buyers can decide what they want.

[pepz]

Only noticeable difference is .2" more lowering in front for non M and .05" less drop in rear for non M. It is interesting that there is different lowering specs for M and non M.There is no mention of spring rates. You would think M version has higher spring rate, but it's not listed.

[IndianaRoadster]

That's what I liked about TC Kline's springs, they gave the spring rate so you could decide what you wanted to go with. I originally went F #450 R #500 but the back was to soft (rear bottomed out sometimes). Ended up going R#700, which was perfect.

[zellamay]

Only noticeable difference is .2" more lowering in front for non M and .05" less drop in rear for non M. It is interesting that there is different lowering specs for M and non M.There is no mention of spring rates. You would think M version has higher spring rate, but it's not listed.

I wouldn't rely on those numbers much. I've even seen different numbers, on different sites, for the same H&R springs. Also, as this thread reveals, the drop is not all that predictable. Now, if H&R was willing to state how they got those numbers (they won't), then one could make an informed decision. Are those number calculated?... tested with correct weights? ... randomly compared on one car?

[BimmerBreaker]

The 6 cyl Z3's (non-M) all have aluminum blocks, so probably weigh close enough the to the iron block 4 cyls that those two models use the same springs. The M's with their iron blocks probably have a bit stiffer, or taller springs, to compensate for the added weight. Using non-M stuff on an M would likely result in a car that sits even lower.

[bluptgm3]

The 6 cyl Z3's (non-M) all have aluminum blocks, so probably weigh close enough the to the iron block 4 cyls that those two models use the same springs. The M's with their iron blocks probably have a bit stiffer, or taller springs, to compensate for the added weight. Using non-M stuff on an M would likely result in a car that sits even lower.

On E36 Coupe/Sedan, the “M” springs are of a significantly smaller body diameter than the non-“M” springs, non interchangeable. I assume when same stands true for the Z3.

…..and no sway bar tab on the non-“M” strut casing.
Plus the non-M ‘Hat’ or upper spring perch fouls on the inner surface of the strut tower when the offset ‘M’ Guide Supports/strut mounts are installed. Trim the 328 ‘hats’ or use the E30 or 1995M3 ‘hats’ on the non-‘M’ springs for the required clearance.