Dinan Strut Brace, Camber Plates, etc...
 

I just traded in my 2000 328Ci for a 2005 X5 4.4i Sport... Very happy so far, but I do miss the handling of the 3.

On the X5, I'd like to address understeer and body-roll control (especially when changing directions, e.g. in the middle of an S-turn) I thought I'd first try bumping up the front tire pressure by about 2 psi (I am currently running the stock Sp package 255/55 18" Michelins at 32 psi all around). But I'm also considering a Dinan strut brace, and camber plates...

The front strut brace made a HUGE difference in steering response, turn-in, body-roll control, etc. on my 3 - how effective is it on the X5? Has anyone noticed much of a difference with steering response and mid-S-Turn body control? Also, does it make the ride considerably more choppy over rough, uneven pavement, or is this effect more mild than on the 3-series?

And regarding the camber plates, does anyone have any experience with how well they address X5 understeer... and are there any significant drawbacks, oversteer issues, etc. ?

What other 'favorite' upgrades would you recommend?

Thanks for your help.

- Aaron

Deosn't tire pressure increase upfront reduce the contact patch and thus reduce grip, ineffect increasing front slip or understeer!? It does increase stiffness and make for a firmer ride but I dont know about better grip. I must admit I have limited experience on road-car setup. Just go karts which are a whole different animal.

contact patch size does not change with air pressure. the shape of it changes with air pressure.

more pressure makes the tire stiffer and less compliant to slip forces make it turn in a bit quicker.. its a very fine tuning process. you can get the car more neutral when you adjust more of the suspension (more results from chassis adjustments then from tire pressure)

imo, its a street car and it should have the large amount of factory understeer in it to keep untrained drivers safe (especially since instinct is to lift off the throttle when the rear starts to slide). if other people will be driving your car, i would suggest to still leave in at least some understeer, since you don't know the skill level of the other drivers....

I've always read the oposite... more psi up front is supposed to help a little with understeer.

Agreed. I don't want a drastic change, just more neutral than it is now.
Hayaku, do you have any suggestions for front/rear psi? What do you think of camber plates?

i ran 36 fr/32 rr psi when i had my x5. it was the best compromise i found for turn in and ride comfort on my stock 18"s.

personally, i prefer fix camber plates with fine adjustments by shims over the slotted type or change out the control arms to adjustable ones for camber... i have no idea what dinan offers for their camber plates, but more neg camber up front would help your turn in also (shape of the contact patch is now tear drop instead of rectangular-ovalish)

you can rotate your strut hats or the strut bearings with the stock setup to get more camber now. just disassemble and reassemble the whole thing the way you want it. you can get up to -5 deg camber i believe (way too much).

thats what i said... more psi up front reduces understeer by a tiny amount... :dunno:

I have both (the strutbrace was included in the S2 package) and I think the Dinan camber plates are one of the best mods for the money. They will change the cornering characteristics dramatically and the X5 will go into corners much faster. However the downside of running with camber plates
is that your front tires will start to weave at appr 7000-8000 miles and cause some slight vibration at around 70mph. The solution is to swap either the front tires every 8k or to have them shaved and re-balanced.

- Jan

Dear jmh - was thinking of adding the camber plates with mt Dinan S2 upgrade :cool: - what kind of driving resulted in the weave wear - I have some gorgeous mountain roads with twists'n'turns, but most of my driving is interstate 75+mph - it's going to be real embarrassing having to keep it under 70mph down I15 :loser2: - You do make a good point though, as summer tire set are not rotatable (9.5 n 10.5) - I plan on 18" identical winter set - I will have to look into this further - Any suggestions out there? :dunno:

Sorry - I was respnding to Batman!

I will try bumping up the psi up fron to 36 on your experience...
I just read an article on Motor Trend online (http://motortrend.com/roadtests/suv/112_0406_storm/) where they put the X5 4th behind the Cayenne S, FX45, and SRX (in that order), which is a little disappointing :mad: (The X5 was w/o Sp. package though) Basically, the article complained about understeer when pushed (which I already observed) but also the all-wheel drive system's rear wheel bias as opposed to the Cayenne & FX45's system that utilizes more front tire power to help pull through the turn w/ less understeer... hmm... not sure about that one. (Any thoughts?) They claimed the 5300 lb. Cayenne handled like a sports car!

To those with camber plates: do you think they're worth it overall? I would definately like to take away some understeer, but not with a big sacrifice in stright-line performance and wear.

the monkeys at motortrend can't ever put a real comparison test together because of 2 reasons:
1. they aren't smart enough to figure out how to put the close competitors together.
2. they get paid advertising dollars to bias their results (which they will never admit but its true)

the cayenne is a very very very capable sports car. i've seen and riden in them at the track and they are very nice (haven't driven). the body roll will scare the uninitiated, but the grip the car has is impressive. it is a pig tho. weight transition is slow.

on pro awd cars, the bias is rwd. the most successful mix so far is 30% front, 70% rear for racing. anymore up front and you have to run massive camber and toe out and use berms to turn the car (which means slower straight speed and poorer braking). although, you can get on the power earlier in the turn with awd then rwd alone. its all about trade-offs and gambles in racing...

additional camber will definitely help the x5 reduce its understeer. i doubt you will feel any difference in straight line acceleration or braking.

Yeah, that makes sense to me too... not equipping the X5 with the Sp package should have been a dead-give away at their ineptitude and bias.
I made an appointment for a strut brace and camber plate install for next week (Motor Works West in North Jersey). Next, I will have to start thinking about exhaust, and intake (BTW, Dinan just released the High Flow Throttle Body for the 04/05 engines... )

This is truly a slippery slope!

Hey, give us an update on the camber plates as well. Good luck. The throttle body may quicken the throttle response that many were complaining about in the newer valvetronic engines....Hopefully there is software to go with it. Mind you....you won't get any real extra HP, but probably a better, quicker throttle response.

Actually, I spoke to a guy at Dinan today - they claim about 8hp gain with the Throttle Body, and no s/w required. (The Air Mass Meter does need s/w, though. They say Air Mass Meter, the s/w, and the Cold Air intake should be released "soon") And I believe it's the s/w that improves the throttle response...
Thanks for all the advise - and I'll keep you posted on the upgrades!

Just got the camber plates and strut brace installed yesterday... :thumbup: improvements are FANTASTIC! I noticed a big difference on the first turn; this is the way the X5 was intended to handle. I recommend these upgrades for anyone who likes to drive... uh... enthusiastically. ;)

Do you turn the DSC off? I think the stability control kicks in and distrupts any skid way before the real capability of the chasis.

I thought Dinan did not make camber plates for the 04 and later X5s yet. I thought they only had them for 03 and earlier. What year is yours. Also can you use them if you have full air suspension. I dont think you can. I want to get these soon so any feedback would be appreciated.

Haven't tried turning DSC off yet. Not sure how often I'll being doing that, really... I've read that they mellowed-out the DSC settings on the X5 in '04 - one of the many re-workings for the refresh. I haven't pushed it hard yet, but I've only gotten it to come on once on a really sketchy, tight turn. And even then, I didn't really feel the DSC, just saw the triangle flicker in the instrument cluster out of the corner of my eye. :)
In my 328Ci, the DSC was a real party-pooper though. Seems like they did a much better job with this on the new X5's.

Mine is a 2005; the camber plates fit the same on the new X5's as on the older ones (and as far as I know, air suspension does not make a difference either). The strut brace fits both new and old X5's too, although the air suspension models get a slightly different version...
The camber plates were $249, plus $350 for installation at Motor Works West in NJ. (Also, they recommend an alignment after the camber plate install, so that was another $150)
The strut brace was $599, plus $45 for installation. The grand total was about $1475 :wow: ...but the difference is worth it.

Dinan X5,
Thanks for the info on the parts. I am going to get the camber plates soon. I am going to hold off on the strut brace because i think the camber plates are responsible for about 90% of the increse in grip you are getting.

Instead of the strut brace i am going to get the throttle body dinan makes thats good for 8 hp. By the way are you getting the throttle body or do you already have it. If you do let me know how you like it.'

Thanks
Tony

Tony, does Dinan sell those camber plates? Could you elaborate on how the camber plates aid in the handling on the front end? I have only seen strut braces sold by Dinan.

Thanks

Batman - check out the Dinan website - It will explain better than I and give you some more ideas.

Yes, the camber plates are Dinan. They help handling by giving the front wheels -.5 degrees of camber (picture the 2 front tires tilting just a hair so that the tops are closer together - if you're looking at the car from the front they go from this: | | to this: / \ ...OK, obviously not nearly that much, but you get the idea :) This alteration of angle gives them a better bite when cornering, and effectively corrects the excessive understeer.

I agree that the camber plates comprise the majority of the improvement. The difference is noticable in almost any turn, but the improvement is astounding in tight turns.
The strut brace is more subtle... it just seems to keep the front end more planted and settled when initiating a corner, and even more so when changing direction (like in the middle of an S-turn). The strut brace definitely does not make a drastic change like on my old 328Ci; some may not even notice the difference on an X5.
I don't have the throttle body - yet! You're probably right to start with the camber plates and the throttle body, and wait on the strut brace. My though was just to do all of the handling improvements first, and come back for the power tuning when Dinan releases the CAI, and the engine/trans software.

Well thanks anyways. I knew what camber is. Specifically how does the camber plates increase the negative camber, and why not just adjust the camber directly on the suspension since the X5 has that adjustment!? BTW, how does it affect staightline speed and tire wear?
Thanks