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B C

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Posts posted by B C

  1. 13 hours ago, patsbimmer1 said:

    We bought my son a new bike as an early birthday present. 

    I got my kids onto bikes with hand brakes and derailleurs as soon as I could so they could become little shreddies on the MTB trails. 
    With how quickly they grow it is hard to justify getting them each a $400 Trek so I’ve tried to find the best department store bikes and upgraded things to make them a bit safer and more trailworthy.


    Looks like he has a great bike! Time to try out Minooka

  2. Delivery times for parts have been very slow lately.

    I ordered 7” long 350 lb front springs instead of 6” long 350 lb fronts as well as some new pinch bolts for the knuckle/kingpin. It all finally showed up today and I got the 6”ers swapped out for 7”.

    How is it?

    Let’s use letter grades to compare the old 6” 525 lb/650 lb setup to the 7” 350 lb/ 430 lb setup.

    Ride Quality Before: D+, fine on smooth roads, brutal on concrete roads/sea-sick on some freeways

    Ride Quality Now: A-, its not a brand new Lexus, but for still being approximately double the stock spring rates, I dont believe the firmness of the ride would draw the attention of a normal person very readily.

    -

    Handling Before: A+, razor sharp turn-in, completely flat, and neutral. Automotive nirvana.

    Handling After: B-, turn-in is not what im used to, body roll is there but pretty minimal, balance is biased to mild understeer at the limit which may be neutralized with another 0.5 degree of front camber. I’m probably getting ahead of myself as I still need to get the alignment and check to see if any sway bar preload needs to be neutralized.

    -

    Ride height before: B+, form follows function, but it looked great, if not just a tad higher in front than rear. Never any scraping or bottoming out.

    Ride height now: C+, no rubs or bottoming out thank goodness, but the front is too low and I need to raise it up 3/8-1/2”.  
     

    im expecting that I can get the handling up to a B+ and ride height to an A-.

    im not there yet with the setup, but even as it sits daily driving will be even better than before. 

  3. This car’s setup is at home and in its element while on the smooth pavement of the track. I consider it a streetable track car when I need it to be a trackable street car.

    I started down the path of shopping more street oriented coilover setups but was persuaded by Ground Control to try a “proven setup” by going from the 6” 525 lb/in front,  6” 650 lb/in rear springs, to some 6” 375 lb/in front/ 7” 430 lb/in rear.

    For reference, VAC Motorsports classifies the following spring rate combinations:

    Performance with Comfort 300/450 

    Aggressive Street Car 450/500

    Track days (minimal street use) 550/600

    the 375 springs were unavailable and I felt that the rear to front spring rate ratios were a bit too close so I chose 350/430 as it matches the proportion of the current spring rates better.

    I was concerned that the 6” fronts were going to be too low and ordered some urethane spring pads to add compliance and 3/4” of material to help with the ride height. 

    The pads ended up not fitting as nicely as hoped on the front but I am running 1 on the rear springs. (Old 6” 650 lb/in rear spring on left, new 7” 430 lb/in rear spring on right)

    2AACF4A5-7334-4A3A-BADD-AD210FC0B4C8.thumb.jpeg.22c089e45d3629d5f555ceb7297bc49b.jpeg
     

    old 6” 525 lb/in front spring on left, new 6” 350 lb/in spring on right

    9ED2D3DA-B10E-406F-88D5-8FE1518CD3CD.thumb.jpeg.00238bf46da32c29b0073a3da003504d.jpeg
     

    The new spring rates are almost smack dab in the middle of stock rates and the previous rates.

    with everything together the rear sits 7/8” higher than before and the front sits 1/2” to 3/4” lower than before with no ability to adjust it any higher.

    4C93E1A1-CC0F-4153-8B43-A7661B104F5A.thumb.jpeg.cbb87f27296c5e1a67b7a3432fa81fe7.jpeg

     

    I welcome a slightly higher ride height for practicality but am targeting 1/2” higher overall from before as a starting point before getting it dialed in, mainly to provide more suspension travel before contacting the bump stops. Right now there is about 1”, which is what GC suggested. (For comparison, Stock E90 M3 has 1/2” of travel before hitting bump stops according to a bump stop article I was reading by Dinan).

     

    DB302AEB-F8F5-4345-8111-90DFA76EDF90.thumb.jpeg.c23ad074f19aef6ec9a4e0381891364f.jpeg
     

    My test drive was limited because there was some rubbing on harder turns from how low the front is. Hopefully not speaking too soon, but the ride quality is still firm. It feels like a lowered car. I definitely need to lower the rebound damping in the rear.   The best way I can describe the ride quality difference is there are certain bumps that make you clench, but hitting them now was not a clench-worthy moment.

    Turn in is no longer razor sharp, but compromises have to be made.

    I ordered some 7” long front springs which will actually allow for some height adjustability and wont clank around when the car is in the air.

    Hoping by next weekend ~ May 1st I can have things sorted and ready to take to Big Bear for the final touches

  4. 27 minutes ago, P_Roloff said:

    Most of the nice sounding ones are running catless headers+resonators with an aftermarket muffler and are just stupid loud. It seems that adding back quieter mufflers just seems to cut the noise but maintain the rasp, which is exactly what I would want to get away from. I wonder if going to quad resonators, x-pipe, catless headers, and a moderately quiet muffler would be the solution?

     

    Have any pics of said muffler guts?


    note the perforated pipes

    image.jpeg.a96eaf532b190a5e86c9ca622e3fb438.jpeg

    Interestingly the Z4M seems to have better luck with muffler options that sound good.

    The stock exhaust sound isnt BAD, it is unique if not just a little bit exotic, but it isnt a sound that gives James May a fizzing sensation. 

    The risk comes with modified exhaust as you can really ruin it, making it worse than stock. 

    @pynacl  I wish you godspeed, just not a Godspeed exhaust

  5. All videos with really good sounding S54s are deepfakes of an E36 M3 with a pitch adjustment /s

    It is entirely possible to have a great sounding S54 but I have yet to find a quiet setup that sounds good enough to spend money on. Loud enough to actually hear it while driving but quiet enough to hear the induction sound and not be a nuissance.

     

    When you see inside the stock muffler its a bit baffling at how they arrived at such a design. 

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