Some Interesting Findings on the Dinan Stage 1 Kit

lucid wrote

Are you sure the coupe kits they are currently selling do not have the modified parts?

according to Dinan, coupe kit doesn't have rear spring pockets/spacers. And that's why it's 100 bucks cheaper than the sedan kits.

lucid wrote

Modification of the spring specs does not have to result in a change in the drop. They could have changed the stiffness and the natural length specs of the spring in conjunction with the spacer to preserve the drop. For instance, a softer spring with the same natural length would yield more compression, which can be offset by the spacer to preserve the drop. We might or might not get conclusive info on this. Trying to see if the drop has changed would still be useful though.

Only if they did change the springs specs which I doubt ...

That measurement can show us if the stock car or V1 car sits the same way or lower ... If they didn't change any specs on the springs and added a spacer then it definitely should raise the car by 1/8 ...

isugoo wrote

according to Dinan, coupe kit doesn't have rear spring pockets/spacers. And that's why it's 100 bucks cheaper than the sedan kits.

OK. Thanks.

I am going to call Dinan today to try to find out for sure but the only thing I can think of now is maybe they found out that with a fully loaded car, gas, trunk, 3 adults in the back, the car would slightly rub in the rear at certain times. Why else would you add 1/8 of an inch back to the ride height? It would certainly be easier to do this than get the springs redesigned. Anyway I might be glad I have the V1 kit after all.

Isugoo - Did you have a full tank of gas or a load in the car when you took your measurements? I know we are talking fractions of an inch here but I have the stock PS2s with 8000 miles on them and as I said a little less than 1/2 a tank of gas with no other weight in the rear when I measured last night.

If you guys are measuring center of wheel hub to top fender line, tires and wheels don't matter. (Actually, a large wheel offset or wheel cap position difference would have a very small effect, but I wouldn't worry about it.) It'll be hard to obtain meaningful measurements if there is indeed an intended nominal difference of just 1/8".

AMPowerJ wrote

I am going to call Dinan today to try to find out for sure but the only thing I can think of now is maybe they found out that with a fully loaded car, gas, trunk, 3 adults in the back, the car would slightly rub in the rear at certain times. Why else would you add 1/8 of an inch back to the ride height? It would certainly be easier to do this than get the springs redesigned. Anyway I might be glad I have the V1 kit after all.

Isugoo - Did you have a full tank of gas or a load in the car when you took your measurements? I know we are talking fractions of an inch here but I have the stock PS2s with 8000 miles on them and as I said a little less than 1/2 a tank of gas with no other weight in the rear when I measured last night.

My car had 2/3 tank of gas with stock 19 and about 4600 miles on the odo.
With my small hand, 1 finger fit gap on the back, 2 fingers on the front.

Stock rears were already low so I'm happy with 1 finger gap.

BUT WHATEVER IT IS ABOUT THE PRICE, PRE-MATURE REVISION, I LIKE THE KIT A LOT (if I don't think about how much I spent).

I'm really liking my Dinan suspension kit. It exceed my expectation by miles. Extremely civilized compare to regular stiffer lower springs.

Sometime I feel that it's even softer and comfy than stock in EDC Comfort setting but still hugging the road better than stock in highway exits.

To be fair, I have to say, they did good job on the kit.
Their own springs with mixed and modified BMW OEM parts, really changed the ride quality.

I spoke to Dinan engineering today.

The guy I spoke to told me that all the engineering that was done on this kit was initially performed on an E92. Then they started getting feedback (he never said they tested any on an E90) that the ride height in the rear may be a little low and cause less suspension travel because of the added weight of the E90. I didn't call him out on this but that doesn't really make sense because we all know the E90 doesn't weigh much more than the coupe and with 50:50 weight distribution we are talking probably 25lbs or so. So the extended perch and spacer is just to increase the ride height 1/4 to 3/8 of an inch in the rear.

Seems to me that Dinan released this kit too soon if they were going to create a specific version for the E90 later even though the version I have was marketed as a E90 kit.

With that being said, I think the need to increase the rear ride height is bogus and I would personally rather have it as low as it can be in the rear anyway. Plus I got a better price on the kit. I see no reason why you couldn't purchase the E92 kit going forward for the E90 if you want it to be lower in the rear and save a few $$$.

I have lost a bit of confidence in the superiority of Dinan engineering over this but like Isugoo said, the ride is great so I am not really going to complain unless I start having problems which I do not anticipate.

AMPowerJ wrote

that the ride height in the rear may be a little low and cause less suspension travel because of the added weight of the E90. I didn't call him out on this but that doesn't really make sense because we all know the E90 doesn't weigh much more than the coupe and with 50:50 weight distribution we are talking probably 25lbs or so.

Just an idea - perhaps it's not the extra weight of the car itself, but rather the load it can take in the rear may be different. E92 only accomodates 2 in the rear, E90 can take 3 adults - which can mean load differences of 200lbs or even more. Also, the difficult ingress in the E92 rear seats probably means that very few Coupe people load up their cars with passengers in the back.

So maybe it wasn't all BS. Which of course doesn't excuse the lack of proper R&D on the sedan on such an expensive product...

adc wrote

Just an idea - perhaps it's not the extra weight of the car itself, but rather the load it can take in the rear may be different. E92 only accomodates 2 in the rear, E90 can take 3 adults - which can mean load differences of 200lbs or even more. Also, the difficult ingress in the E92 rear seats probably means that very few Coupe people load up their cars with passengers in the back.

So maybe it wasn't all BS. Which of course doesn't excuse the lack of proper R&D on the sedan on such an expensive product...

I agree with both, AMPower J and ADC but a little different way.
I would like to consider the new sedan kit I have as an option based on driver's lifestyle and preference.

It seems like it's not type of thing that "must have" for sedan.
It's more like "safe side" for people who often have rear passengers and/or heavy items on the rear seats/trunk space but if it's not the driver's lifestyle, Coupe kit wouldn't be bad idea either.

With all current information we gathered,
Sedan kit seats 1/8" higher with disc spacers and rear spring pockets than coupe kit for weight differences (and possible, lifestyle differences between coupe vs sedan).


One the side note (off topic):
Dinan sent new driver side exhaust with "correct" painted tips yesterday. It took total 3 days to reporting concern to shipping out from warehouse. They also shipped returning label to ship mine back. Extra installation charge (to install this new driver's side) will be reimb. by Dinan after I fax the invoice. (Will let you guys know how long it takes to get reimb. check from Dinan)

AMPowerJ wrote

I spoke to Dinan engineering today.

The guy I spoke to told me that all the engineering that was done on this kit was initially performed on an E92. Then they started getting feedback (he never said they tested any on an E90) that the ride height in the rear may be a little low and cause less suspension travel because of the added weight of the E90. I didn't call him out on this but that doesn't really make sense because we all know the E90 doesn't weigh much more than the coupe and with 50:50 weight distribution we are talking probably 25lbs or so. So the extended perch and spacer is just to increase the ride height 1/4 to 3/8 of an inch in the rear.

Seems to me that Dinan released this kit too soon if they were going to create a specific version for the E90 later even though the version I have was marketed as a E90 kit.

With that being said, I think the need to increase the rear ride height is bogus and I would personally rather have it as low as it can be in the rear anyway. Plus I got a better price on the kit. I see no reason why you couldn't purchase the E92 kit going forward for the E90 if you want it to be lower in the rear and save a few $$$.

I have lost a bit of confidence in the superiority of Dinan engineering over this but like Isugoo said, the ride is great so I am not really going to complain unless I start having problems which I do not anticipate.

So, did they offer you to send those missing parts to make your current kit "perfect" for your car

doba_s wrote

So, did they offer you to send those missing parts to make your current kit "perfect" for your car

Nope. Not sure they would if I pushed but I doubt they would with out additional charge. They just asked if I was having a problem with the setup I have now. I don't want to have to take the car apart again anyway.

Related post; rebate finally received after 24 weeks: http://www.m3post.com/forums/showpost.php?p=6085179&postcount=75

Will Dinan ever respond to this thread?

I still have to say with all this trouble:

a. still I love the products. whatever they did with modifying the parts, it works great. the ride quality is truly what they advertised.

b. their customer service was actually great. got an wrong painted tip exhaust on one side but in 3 days, they sent me new one with return label. I can get reimb. installation charge as well.

really only things I disagree with them are:
a. pre-mature revision on the sedan kit.
b. price. price. price.

overall, I'm happy with my setup although bank account is a bit empty now though.

isugoo where are the pictures of your car ?

isugoo how much did you pay for your exhaust ?

I am pretty sure it was 1999 on their website, but now it is 2299 ?

Looks like they decided to raise their prices by 10% ...

doba_s wrote

isugoo where are the pictures of your car ?

Hahhaa- Sorry, I'll take pictures soon. I took some but lost them. =(

doba_s wrote

isugoo where are the pictures of your car ?

Pretty bad pictures but well, I promised and here are the pictures.
Stock front: 3 finger gap.
Stock rear: 2 finger gap.

Dinan front: 2 finger gap.
Dinan rear: 1 finger gap.


Drivability: awesome. I didn't expect this much but man, hate the price tag but drives awesome. Not rough at all like other springs. Very smooth but hugs the roads better. Lovin it.

here is my rear wheel



and this is an old picture with 19" ...



I got 18's now and the gap might be even bigger

doba_s wrote

here is my rear wheel



and this is an old picture with 19" ...



I got 18's now and the gap might be even bigger

Hope you got PS2 on your 18s. Your Conti on the 19s breaks my heart.

isugoo wrote

Hope you got PS2 on your 18s. Your Conti on the 19s breaks my heart.

Contis are excellent tires. I'll stay with the PS2s on my car, but I loved the Contis on my e46. For a daily driver, I think the Contis may be a better tire. They are quiet, ride and handle well.

What is it you don't like about the Continentals?