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VTPP Tester Matt Murphy's STX E46 330i

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  • VTPP Tester Matt Murphy's STX E46 330i

    Can the extra grunt of a 330 make up for its' significant extra weight in an autocross setting on street tires?? Who knows, but I'm working on finding out.

    I've documented quite a bit about my build over on BimmerForums, but I thought I'd post here too. (I get bored at work)

    As it sits:
    AST 4200's
    Vorshlag camber plates
    H&R non-M bars
    18x9 SSRs w/ 265/35/18 tires
    Jim Blanton LSD
    old Sparco MonteCarlo seats I picked up cheap (just above 25# with sliders, won't fit anyone over 200lbs)
    ETX18L 18lb battery
    Vorshlag RTAB limiters
    Powerflex FCABs
    M3 motor mounts



    Weighs 3,090 lbs according to the Nats scales with a sunroof and stock exhaust and just under 1/4 tank of gas. For reference the E36's are weighing in around 2850.

    Andy Basham made it work in 2005, taking 2nd in STX, though with a pretty full-bore build, and a ZHP, which has a higher final drive ratio than my sport package. He was using TC Kline DAs, 500/500 rates, and 30/25 bars.

    He got his to about 3050 without a sunroof, so I think I should be able to get mine a bit lighter than that, even with a sunroof. High 2900's are possible with an early non-sunroof car, though the higher final drive of the ZHP (3.07 to my 2.93) may be worth the extra weight.

    My car started at 550/780, with 27/21 bars on soft/hard. Worked well when the weather was cool, but as it warmed up, grip went up, and I was in the bumpstops up front, giving some pretty ugly push. 650 lb springs up front and the bar on stiff got rid of the push. With the front sticking well, now the rear is wild, so right now I'm at 650/550, though I feel like ultimately I may end up at 650/650. Still working on sorting out the rear end.

    I'm able to get about 3.5* of negative camber up front, which is less than the E36's get, but should be enough if I keep the car stiff enough. Pyrometer readings thus far show it to be enough, though it'd be nice to get more.

    I started on the RE-11s, but found them to not like heat. They'd be brilliant for the first two runs, but as we'd learn the course better and drive better, the tires would fall off and we'd have slower times. We're on the AD08's now, and they seem to tolerate the heat well.

    I drive this car *every day*. This is my only car, and I'm loving it in STX trim. I drive on the Yok's every day as well. I've put about 10,000 miles on the car since April, and I'm not looking forward to yanking a bunch of the parts for winter. I'm begging AST to make some non-adjustable shocks that I can run with my M3 springs in the winter. =]

    We have three more local events to go this year, two of which are back to back at one of our better sites, so we'll see how the changes to the rear end work up against some national-calibre competition. Then on to next year...

  • #2
    Re: VTPP Tester Matt Murphy's STX E46 330i

    oh yeah, just looked up Basham's thread, apparently he had is car down to 3,096ish, so I'm already below him, with a stock exhaust still on there, and larger wheels & tires. That puts the 2005 ZHP at around 100-120 lbs heavier than an earlier 5spd if you assume the sunroof is 50lbs.

    ZHP has a 3.07 final drive and 2.5 2nd gear for 7.675 2nd gear
    5spd has 2.93 final drive and 2.49 2nd gear for 7.2957 2nd gear

    So ZHP has ~ 5% gearing advantage. ZHP peak hp advantage is due to a different cam, so that's a wash. the ZHP does have a faster steering rack, which is nice when autocrossing, but not a performance difference.

    Does anyone have thoughts on whether a 5% gearing difference is worth 100lbs?

    Comment


    • #3
      Re: VTPP Tester Matt Murphy's STX E46 330i

      Hmm... ZHP has what, 10 more hp? But I assume those cars only came with the sunroof (I think it was 2003 that all E46 non-Ms came with the sunroof, and ZHP was only built 2003-2006)

      I wouldn't lose any sleep over such a small change in final drive ratio (3.07 to 2.93). The E36 cars had a huge range of final gearing, I believe from as tall as 2.93 down to as low as 3.91. That small bump for ZHP would be almost not noticeable.

      I suggest spending the time and money building a purpose built ST legal lightweight exhaust. The BMW stuff is HEAVY... you should lose 40-60 pounds, or even more if you are already hearing impaired. Does your E46 come stock with a cast exhaust manifold or tubular style header? An aftermarket header would a good bit be lighter as well.

      I doubt the small advantages the ZHP has would be worth changing your car for, or adding the potential for more weight. I'm looking at non-sunroof E46 cars for my DSP build, just to keep the weight down... but I can update/backdate to get any of the better ZHP bits.

      Very encouraged at the weight of your car... in SP trim (no a/c, no airbag steering wheel, aftermarket intake manifold, no radio, lighter seats, no emissions requirements) it would lose even more, and without a sunroof... wow, the E46 is not sounding too shabby.
      Terry Fair - www.vorshlag.com
      2018 GT / S550 Dev + 2013 FR-S / 86 Dev + 2011 GT / S197 Dev + C4 Corvette Dev
      EVO X Dev + 2007 Z06 / C6 Dev + BMW E46 Dev + C5 Corvette Dev

      Comment


      • #4
        Re: VTPP Tester Matt Murphy's STX E46 330i

        yeah, my ZHP thoughts are mostly about what to do when it's time to replace this car, as I'm about to hit 100k, and put about 20k a year on it. It's been very reliable, but at some point every car slides down the reliability scale below the daily drivable point for a working professional.

        I definitely noticed the gearing difference when driving the two back to back, but I'm not sure if the buttdyno translates into actual time when laden.

        I'm thinking an "unmuffler" and some hanger bits to make changing easier. I don't think a compromise exhaust will ever be as light as I'd like it for big events, or as quiet as I'd like it for DD.

        The header is definitely heavy, and restrictive, but that's partly because the cats are in there. So while I could replace it with good aftermarket headers, gain some hp and lose some weight, my options are both expensive and dubious as to whether I could keep it from throwing a CEL. (and replacing cats inside the header is certainly not as easy/cheap as doing so in the exhaust pipe)

        Of course, no worries for a DSP build...

        I looked back at Basham's thread and I guess his was a 2003, not a 2005, and did have a sunroof, and also had the cold weather package. So maybe the newer cars aren't necessarily that much heavier, looks like about 50-70 lbs. (accounting for 10lbs heavier wheels & tires on my car, and assuming about 10lbs for the cold weather junk) Still, a non-sunroof ZHP was only possible for half a year, so the 2001-2002 can still end up 100-120lbs lighter than any ZHP you can actually find. (getting this car under 3,000 lbs would be pretty sweet!)

        The 10hp on the ZHP is just a cam and software, it just shifts the power around, doesn't make more "area under the curve" as I like to say. Not worth bothering power-wise.

        Comment


        • #5
          Re: VTPP Tester Matt Murphy's STX E46 330i

          I've got some time on my hands, so I thought I'd post up my plans for next season. Our first event isn't until May 1st, so I have some time to think...

          Winter:
          - water pump replacement
          - coolant expansion tank replacement
          - new (OE) front pads

          Pre-season:
          - change diff fluid
          - install some sort of chip
          - install stronger tranny mounts
          - install pulleys
          - install an intake?
          - buy 10mm spacers
          - buy 15mm spacers (for testing w/ stock rear sport package wheels)
          - install 75mm studs
          - buy a pair of 650lb springs for the rear
          - test fit 10mm spacers up front w/ 265mm tires, I think they should fit

          April TnT in Lincoln (hoping Evo does one again this year):
          - test 265/265 vs. 265/255 vs. 265/245 vs. 255/255 tire options, to see if I can gain a gearing advantage without giving up too much lateral grip
          - once the tire package is sorted, test 650/550 vs. 650/650 vs. 650/780 spring options

          Mid-year:
          - intake if not already done
          - exhaust and possibly header solution
          - strut bars if I have the money (not likely)

          It'd be nice to rig up some sort of strut sensor that lets me know if I'm getting into the bumpstops, but I likely don't have time/money for something that fancy.

          Neal Tovsen will be running the Darrylmobile (now belonging to Neal) locally, so I should have a very clear understanding of where I stack up nationally, but I also plan to hit the Milwaukee and Lincoln Divisionals, as well as Nats.

          Comment


          • #6
            Re: VTPP Tester Matt Murphy's STX E46 330i

            Originally posted by murph View Post
            It'd be nice to rig up some sort of strut sensor that lets me know if I'm getting into the bumpstops, but I likely don't have time/money for something that fancy.
            zip tie on the shock piston will give you that information. any experienced local should be able to give you a how-to on that.

            What's Darryl running now, btw? Jump ship to STR like the rest of the world?

            Comment


            • #7
              Re: VTPP Tester Matt Murphy's STX E46 330i

              Originally posted by rp1 View Post
              zip tie on the shock piston will give you that information. any experienced local should be able to give you a how-to on that.

              What's Darryl running now, btw? Jump ship to STR like the rest of the world?
              Yeah, I've been using the zip tie method, and got them out of the bumpstops under the conditions I was testing, but it'd be nice to see data that tells me when conditions have gotten grippy enough to get them back into the bumpstops, so I know when to adjust in what direction if I'm getting front end push.

              Darryl bout a classic 2002 show car. I don't think he'll be doing as much autocrossing this year, but we'll see.

              Comment


              • #8
                Re: VTPP Tester Matt Murphy's STX E46 330i

                Sounds like he's laying low testing an '02 for ST. Down with the Civics! (or maybe that's just my dream)

                Comment


                • #9
                  Re: VTPP Tester Matt Murphy's STX E46 330i

                  ok, lots of work done so far this winter, and especially in April:

                  - water pump
                  - expansion tank
                  - fluids
                  - DIY intake
                  - TMS underdrive pulleys
                  - fresh plugs
                  - diff/tranny fluid
                  - tranny mounts
                  - longer studs
                  - "summer suspension" installed, along with 650lb rear springs
                  - front seat mount adjustments
                  - 18lb battery reinstalled
                  - RE-11s mounted

                  I've been chasing a clunk, so I ordered a reconditioned steering rack, attempted to install it, and had to abort, it was screwed up. A replacement is on the way, and then I'll get the performance alignment done next week, right before our first event of the year.

                  I decided the strut tower bar is probably important, but I'm not sure the expensive Mason bar is going to fit, so I bought a cheap used IE bar. Unfortunately that won't get to me until after next week, so if anyone has a Mason bar lying around, it might be worth the extra cash if I can get it next week.

                  I got an estimate of $1,000 on the exhaust (not including header) so I'm going to have to think long and hard on that. I'm not sure 30-40 lbs is worth $1,000 and a certain loss of street freedom. (I can gun it whenever I want now, no unwanted attention)

                  With the fresh plugs, pulleys, and intake, the car feels much faster than last year, and now I'm skeptical that gearing improvements will really help it, but I'll be testing anyway. We have back to back TnT's May 15/16th, so lots of opportunity for testing that weekend.

                  Comment


                  • #10
                    Re: VTPP Tester Matt Murphy's STX E46 330i

                    Quick update as the season progresses...

                    Getting to a proper ride height is important. Especially with those struts up front, gotta keep them in their camber happy place!

                    I think the setup is finally at a place where I'll call it good for the season, and concentrate on driving in prep for Nats. I don't think it's perfect, but it's time to stop having to learn a new car every event.

                    Here's where I'm at:
                    13.5"/13.5" ride height
                    650/780 springs
                    30mm H&R bar on medium front, 21mm H&R bar on soft rear
                    265mm Dunlops

                    My next event is the Milwaukee Divisional, then the Lincoln Divisional and Nats are right around the corner.

                    Comment


                    • #11
                      Re: VTPP Tester Matt Murphy's STX E46 330i

                      Just a pre-Nats update, did a little tweaking. As I get more comfortable with the setup, I like the rear end a little looser.

                      I'm now at 13.5" front, 13.25" rear, but jacked the rear swaybar up to full stiff, and the rear compression nearly to full. I'd rather be using 850 lb springs in the rear with less rear bar, but I won't need as much stiffness after nats, (running on poor surfaces locally) so it seems a little silly to purchase the stiffer springs and then have to try to tune around them if the Nats TnT course might not even reflect a proper nationals-style element size and speed.

                      The car worked great in Lincoln last weekend at the MidDivs, and is liking the concrete a lot. I had my best result ever at a national-level event, taking 5th in STX, just one shy of a trophy, and right there with a bunch of nationals trophy winners.

                      During Friday's Evo TnT I tested 265mm Front, 255mm Rear tires, to see if I could dial in more oversteer and take advantage of the better gearing of the 255s. The 255s felt better in terms of getting rotation, and the gearing difference was noticeable on every corner exit, but ultimately the 255s were consistently slower. This porky car needs every bit of grip it can get, on whatever end it can get it!

                      I also weighed the car, it came in at 3,056 lbs at race fuel. (just over 1/8 tank) I can still drop 10-15 lbs in the exhaust, maybe 20-30 lbs in brakes, and 35lbs (?) if I swapped the roof, but those are all rather expensive endeavors, which likely won't happen since the car is really only trophy-level competitive.

                      I was surprised to hear that the STU E46 M3s are weighing in around 3,200 lbs, it's unfortunate that they're so much heavier.

                      Comment


                      • #12
                        Re: VTPP Tester Matt Murphy's STX E46 330i

                        Originally posted by murph View Post
                        I also weighed the car, it came in at 3,056 lbs at race fuel. (just over 1/8 tank) I can still drop 10-15 lbs in the exhaust, maybe 20-30 lbs in brakes, and 35lbs (?) if I swapped the roof, but those are all rather expensive endeavors, which likely won't happen since the car is really only trophy-level competitive.

                        I was surprised to hear that the STU E46 M3s are weighing in around 3,200 lbs, it's unfortunate that they're so much heavier.
                        That's surprising to hear. I've heard a few people with zero option M3s are around 3150 without anything done to the car...but there were no pictures to prove it. I wonder if these were sun-roof'd cars.

                        Great little update, btw! See you in a few days!

                        Comment


                        • #13
                          Re: VTPP Tester Matt Murphy's STX E46 330i

                          Yea, the 265mm tires make more sense on any car that heavy. I'm not too surprised they are faster, but I was unsure if the 9" wheel limitation in STX would hamper their ability to add more grip. I guess you proved it didn't.

                          See you there in a few days!
                          Terry Fair - www.vorshlag.com
                          2018 GT / S550 Dev + 2013 FR-S / 86 Dev + 2011 GT / S197 Dev + C4 Corvette Dev
                          EVO X Dev + 2007 Z06 / C6 Dev + BMW E46 Dev + C5 Corvette Dev

                          Comment


                          • #14
                            Re: VTPP Tester Matt Murphy's STX E46 330i

                            This winter I have some big setup changes planned, and so I'm getting much more aggressively scientific with this build. I'm going to take the measurements for motion ratios, unsprung weight at each corner, center of gravity, and plot the camber change through roll.

                            I hope to combine all this info with the notes I have on where the car did well in what conditions on what settings, and come up with setups for next year. I'm hoping to get more camber next year, use less spring & more bar, and less overall roll resistance up front, with more spring, less bar, and more overall roll resistance in the rear next year.

                            THIS PIG WILL TURN! =]

                            The setup will be flexible, so I can run the car on crappy surfaces in 40 degree weather and at LAP in 80 degree weather.

                            Comment


                            • #15
                              Re: VTPP Tester Matt Murphy's STX E46 330i

                              Just a quick pre-season update, with the new car and new plans...

                              First, I bought a new car. I found a non-sunroof ZHP out in CA in immaculate shape for a good deal, I couldn't pass it up. So the rolling couch is for sale, though in essentially stock trim.

                              Next, I decided the driveline needed attention. I upgraded the subframe bushings on my new car to AKG 80A poly, the diff bushings to Meyle HD, and I'm waiting on some Bimmerworld solid rubber motor mounts to compliment the rogue solid rubber tranny mounts already on the car.

                              Next, I had the LSD rebuilt with the ZHP-spec 3.07 final drive.

                              Then, I said what the hell, threw caution to the wind, and ordered myself up a set of AST 5220GA dampers. With the remote-reservoir connections mounted below the camber plate, if I want I can tuck the strut top nut up under the sheet metal of the strut tower, so the little opening is no longer a limitation to how much camber & caster I can get.

                              So, as a recap, I think the car last year was a solid trophy-level car. This year will see improvements in the following areas:
                              - camber
                              - caster
                              - gearing
                              - power
                              - driveline slop
                              - center of gravity

                              We'll see where the weight lands, I haven't weighed the car yet... I'm guessing around 3,050 lbs, just because the newer year ZHP car has extra standard stuff like the HK stereo, the brackets for the cd changer, the bigger front subframe plate, etc.

                              The same old klutz will still be driving it, but it'll sure look nicer while I'm finishing mid-pack!

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