Author Topic: Wrong HR Springs? (Read 7516 times)

tophertii · « **on:** October 02, 2006, 11:31:49 AM »

I recently purchased an IS. The first thing I did was rebuild the suspension. The car now has new control arms with Bavauto offset urethan control arm bushings, new sway end links, Billy Sports and HR Springs.

I bought the springs from BMP. I sourced them from BMP because they had a decent price, free freight and were close enough that I would receive them in time to install them over the weekend with all of the other parts.

When I placed the order I gave them the application and told them that I wanted sport springs not OE. I got all of the new parts on the car and lowered it. It didn't seem like much of a drop, I was expecting more. Unfortunately I didn't measure stock height before the install, I got too anxious.

I checked the box and the part number - 50406. The description on the box says E30 M3 16v 1987-92. I then researched the springs a bit more and found that other vendors are showing at least three part numbers for the application, that is not including the OE's and the race springs.

One website list the drop at 1" front and .75 rear for the E30 M3. It also lists the drop with these springs for a 325 @ 1.3 front and 1.3 rear. I called HR and the voice confirmed this. He also said the only application that he shows for the 318is is 50404.

First off I'm a bit dissapointed with the drop but more importantly I'm concerned that that front to rear spring rate bias is incorrect for the front to back weight bias of the car. I would think that a 325 would be heavier in the front than our cars. Seems if you had the wrong spring rate bias you could be playing with understeer oversteer issues. Since the springs were intended for a four cylinder car - M3 - it may not be that big of a deal.

I plan on doing some autoxing and maybe do a couple track days/driving schools. I know that suspension set ups can be highly subjective but do you all think about this? Is my thinking about matching the spring rate bias to the weight bias of the car wacked? Any experience with these springs?

///Motorsport · « **Reply #1 on:** October 02, 2006, 12:16:48 PM »

So have you figured out what springs they are? I would go for H&R Race, I believe I ordered mine for an M3 but it could have been for a 325is, I cannot remember, I guess I didn't think it would be a big deal.

Euro Nation · « **Reply #2 on:** October 02, 2006, 12:27:10 PM »

As far as I know the M3 weighs almost as much as a 325is. The 318is is lighter on both ends (ever notice your car probably doesn't have that 55lbs of trunk tar all the 6cyl guys whine about?)

Febi Guibo · « **Reply #3 on:** October 02, 2006, 12:59:37 PM »

i used the #29964 H&R sport springs for the M10 318i ...they are nice and firm and have a fine drop, perfect for crappy NYC streets. There are a couple of other dudes on here with them.

I suspect there is little difference between the new style H&R sports for the 325is and the 318is, having seen both in person.

rfritz · « **Reply #4 on:** October 02, 2006, 01:01:13 PM »

There are some for sale on s14.net for $150 right now. (318i)

thumper3ld · « **Reply #5 on:** October 02, 2006, 01:48:09 PM »

The springs you have are H&R Race springs for our cars. Those are the numbers on mine.

FL318is · « **Reply #6 on:** October 02, 2006, 02:13:27 PM »

I hope to be getting a part time job and will be doing some mods and repairs. With all the talk about H&Rs I am getting confused between OE and Sport or versa visa. This link calls for the 50404

http://www.hrsprings.com/site/index.html

So which spring does the 318is need, not for max drop but rather replacement?

Febi Guibo · « **Reply #7 on:** October 02, 2006, 02:50:45 PM »

my springs are sports, and are the best for OE handling with a slight drop... kind of like, "OE the way they should be"

thumper3ld · « **Reply #8 on:** October 02, 2006, 02:52:07 PM »

Screw OE handling. Its all about kidney rupturing race like feel.

m42 fan · « **Reply #9 on:** October 02, 2006, 02:52:52 PM »

Quote from: FL318is

I hope to be getting a part time job and will be doing some mods and repairs. With all the talk about H&Rs I am getting confused between OE and Sport or versa visa. This link calls for the 50404

http://www.hrsprings.com/site/index.html

So which spring does the 318is need, not for max drop but rather replacement?

yes, the OE are the ones you are looking for. BTW, ignore my sig, I ordered the springs the other day from Turner. Hopefully they will not be on backorder for terribly long...

Brian

tophertii · « **Reply #10 on:** October 04, 2006, 08:54:33 PM »

Well I learned a bit about H&R springs today. I called BMP's customer service on Monday and explained that according to H&R's customer service and website the only sport springs actually recommended for my car are part number 50404. The customer service rep said she would research it and call me back in a few hours.

I hadn't heard back from them so I called back today. I spoke with a tech named Anthony and he explained that they chose those springs over the 50404 because they are much stiffer. The rates are at work and I will post them tomorrow. Anthony said they tested the different rates by running them on the track and the 50406 produced faster lap times than the ones recommended by H&R. From what Anthony said the 50406 is stiffest street spring the H&R offers to fit our cars. I said that I was disapointed with the drop and said that from what they have measured the recommended springs only give an additional 1/8th of drop over the recommended springs.

I have gone from damn what am I going to do with these springs to I can't wait to try them. BMP could be trying to get out dealing with me wanting to return them but they said they would swap them if I wanted. FWIW

thumper3ld how is the ride with your springs. Tell more about what you think of them. Thanks

thumper3ld · « **Reply #11 on:** October 04, 2006, 10:52:26 PM »

These springs with bilstein sports on a nice windy road, will make your car feel like a race car. However, on a road thats bumpy, or hitting one nice sized bump at speed, will make your kidneys bleed. Careful when choosing tire sizes also. I recently increased my tire size to 225/50/15 and I was having rubbing issues. I had to correct it by adding an extra 10mm spring pad which did alter the handling alot at first but seems to have gotten closer back to normal after a few days. Its not at what it was before the spring pads so I'll prob take them out once i wear these tires out. All in all, I love these springs. Probably not the best for the rough streets of nyc, but smooth windy roads here and there, make it worth it.

tophertii · « **Reply #12 on:** October 05, 2006, 07:36:40 AM »

Here are some rates. I tried to get them out of h&r but they wouldn't give them up. These come from BMP.

50406 185F 340R
50404 118F 256R

Wizard · « **Reply #13 on:** October 05, 2006, 04:44:57 PM »

Here are some part numbers for H&R springs. Although they do not list spring rates, they do list the amount of drop-- front"/rear".

OE Sport Spring   E30     not cabrio 0.25"/0.0"    50404-55
Sport Spring     E30      not cabrio    1.0"/0.75"     50406
Race Spring     E30      not cabrio 1.6"/1.5     50404-88

bullmand · « **Reply #14 on:** October 06, 2006, 08:46:51 AM »

From the H&R website:

1991 318is/318i
Stage Chassis/Drivetrain Notes F Lowering R Lowering Part #
Sport Spring E30 16V not cabrio 1.25 1.25 50404

1991 325is
Sport Spring E30 not cabrio or ix 1.3 1.3 50406
OE Sport Spring E30 not cabrio or ix 1.0 1.0 50404-55

1991 M3
Race Spring E30 not cabrio 1.6 1.5 50404-88

The Sport and OE Sport springs for the M3 are the same part numbers as the 325is. Hope this is useful.

Edit: Sorry about the formatting, it looks fine until I save it.

Author Topic: Wrong HR Springs? (Read 7516 times)

///Motorsport