Announcement

Collapse
No announcement yet.

Weight loss or power gain

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • Weight loss or power gain

    I have been debating on how to increase my power-to-weight ratio, is it the best (cheapest) to reduce our car's weight or increase our horsepower?

    Our stock power-to-weight ratio is around 14 lbs/hp (2700 lbs - 193 hp).
    If we reduce the weight 200 lbs, our new power-to-weight ratio is 13 lbs/hp.
    If we increase our power to 250 hp (2.5l conversion) and leave the weight stock: 10.8 lbs/hp.

    I am not sure what are the cost to go either way...does anybody have details?

    Thanks

  • #2
    loosing 200 lbs. is weight cheaper then 250 hp. But they still aren't even.

    Figure out how much hp it takes to get to 13lbs/hp. Dyno your car as a base model. And then figure out how much those mods will cost to get you that hp increase (making sure you dyno after getting the mods to verify them (don't think you'll add hp with a k&n filter).

    Are you willing ot remove stuff from the car to shave weight?
    ApexRaceParts.com - Facebook Fan Page - Twitter

    Comment


    • #3
      loose weight! It's not only the bhp/lbs ratio what counts, the handling will improve!
      Brakes will work better, corner speeds will be higher. change the rear diff ratio for better acceleration.
      And if you got some money later, some more bhp will never hurt....


      Goodbye M3, you served me well.

      Comment


      • #4
        ^ truth
        I'd take a light weight low HP car over a heavier high HP car any day!

        Comment


        • #5
          It all depends on what you're optimizing for. If you're optimizing for racetracks, take out the interior and sound insulation and have fun. But if you're using your car for frequent 500 mile trips with a girlfriend/wife, for instance, you should probably add power to preserve the street comfort... as reducing weight pretty much always means the car gets way louder and more raw.
          Seattle, WA
          currently:
          1988 M3, ex j-stock
          1984 911, RoW 3.2
          1990 Peugeot 205 GTI 1.9
          http://cars.g93.net

          Comment


          • #6
            kinda silly saying this but......you should go both ways.:hee:

            carbon fiber hood / AC delete / back seat delete / spare tire delete / carpet + sound deadening material delete / maybe some CF race seats and you've just lost well over 200lbs

            then get yourself a nice CF intake kit with some form of engine management / schrick cams / 48 TB's / 8lb flywheel / sport exhaust
            and
            AWAY YOU GO!:drive:
            JAMES
            sigpic

            Comment


            • #7
              Don't forget the massive reduction in wallet weight ^^

              -Kelly

              Comment


              • #8
                Originally posted by UweM3 View Post
                loose weight! It's not only the bhp/lbs ratio what counts, the handling will improve!
                Brakes will work better, corner speeds will be higher. change the rear diff ratio for better acceleration.
                And if you got some money later, some more bhp will never hurt....
                Uwe nailed it!! Lose the weight first, then add HP. As others have said, it's better to have a light/good handling car than a higher HP/heavier one, within reasonable limits... You're not accelerating and decelerating as much weight so the car will feel better all the way around!!!
                Ron ///Man

                • '91 Gr-A Former CiBiEmme / Ravaglia - Sold
                • '90 M3 Faux EVOII Alpineweiss 36K Orig Owner - The Queen
                • '91 M3 Faux EVO III Brilliantrot Euro Driveline - The Rocket
                • '91 M3 Faux Gr-A Club Racer DM - The Alter EGO
                • '89 M3 M3T / ITR Club Racer
                • '94 Spec E36 - Eh....
                • '09 M3 - Tarmac Terrorist
                • '04 330Xi Sport 6 Speed - Snowmobile
                • '07 530 Xi - Highway Star
                • http://www.imwcarparts.com/e30-m3-parts.htm


                Comment


                • #9
                  To rephrase what others said...

                  Horsepower helps the car accelerate in one direction, weight loss helps the car accelerate in ALL directions. Granted acceleration can be a negative value.



                  - Tire is the other control arm bushing.

                  zhpregistry.net

                  Comment


                  • #10
                    Originally posted by pltfn View Post
                    Don't forget the massive reduction in wallet weight ^^

                    -Kelly
                    Slam! that was funny



                    - Tire is the other control arm bushing.

                    zhpregistry.net

                    Comment


                    • #11
                      Step 1: Do the cheapest first, lose as much weight as you can stand from front to back and the top to bottom of the car (removing carpet and sound material, A/C system, steel hood bonnet)

                      Step 2: Start improving on the power starting with the DME, an Alpha-N piggyback or MegaSquirt standalone is under $1000 and gives modest gains without being too invasive... allowing for further weight reduction removing the stock airbox etc.

                      Step 3: At this point you'll have a fast car, but if more is what you seek do a leak down test & compression test, weigh your wallet and if all is good with the motor a supercharger or turbo system may be up you alley $3500-6K.
                      Eventually the "while I'm in here" bug will get you...

                      Step 2.5: Don't forget a brake upgrade "Upgrades makes objects closer than they appear in the mirror"

                      Step 4: Rebuild to 2.5L or 2.7L, not for the faint of heart or wallet... enter at you own risk.:bones:
                      Last edited by ///schwartzman; 06-15-2009, 11:21 AM.
                      Rich!

                      Comment


                      • #12
                        How much noise/sound increase does a CF hood cause?

                        Comment


                        • #13
                          Originally posted by ///schwartzman View Post
                          Step 1: Do the cheapest first, lose as much weight as you can stand from front to back and the top to bottom of the car (removing carpet and sound material, A/C system, steel hood bonnet)

                          Step 2: Start improving on the power starting with the DME, an Alpha-N piggyback or MegaSquirt standalone is under $1000 and gives modest gains without being too invasive... allowing for further weight reduction removing the stock airbox etc.

                          Step 3: At this point you'll have a fast car, but if more is what you seek do a leak down test & compression test, weigh your wallet and if all is good with the motor a supercharger or turbo system may be up you alley $3500-6K.
                          Eventually the "while I'm in here" bug will get you...

                          Step 2.5: Don't forget a brake upgrade "Upgrades makes objects closer than they appear in the mirror"

                          Step 4: Rebuild to 2.5L or 2.7L, not for the faint of heart or wallet... enter at you own risk.:bones:


                          Where can I get said supercharger system that works reliably for 3500?

                          Comment


                          • #14
                            Originally posted by ///schwartzman View Post
                            Step 1: Do the cheapest first, lose as much weight as you can stand from front to back and the top to bottom of the car (removing carpet and sound material, A/C system, steel hood bonnet)

                            Step 2: Start improving on the power starting with the DME, an Alpha-N piggyback or MegaSquirt standalone is under $1000 and gives modest gains without being too invasive... allowing for further weight reduction removing the stock airbox etc.

                            Step 3: At this point you'll have a fast car, but if more is what you seek do a leak down test & compression test, weigh your wallet and if all is good with the motor a supercharger or turbo system may be up you alley $3500-6K.
                            Eventually the "while I'm in here" bug will get you...

                            Step 2.5: Don't forget a brake upgrade "Upgrades makes objects closer than they appear in the mirror"

                            Step 4: Rebuild to 2.5L or 2.7L, not for the faint of heart or wallet... enter at you own risk.:bones:
                            Step 5: Go on diet...eat less of them Burgers....That is a lot of weight.....LOL....
                            Lawrence

                            BMW CCA San Diego Chapter #192742
                            '90 M3 AWII - Garage Queen
                            '09 540i Touring 6 Spd - Son's DD
                            '03 530i 5 Spd - SO's DD
                            '03 Nissan Frontier Crew Cab - My DD & Range truck
                            '05 330i ZHP 6 Spd - Alternate DD
                            '15 Honda Pilot - Daughter's & Grandkids Hauler

                            Comment


                            • #15
                              I am a material engineer...so material weight is always on my mind. Here is a list of upgrades that I wish to make eventually (in no particular order):
                              - CF hood
                              - CF fenders
                              - Light forged wheels
                              - Full titanium exhaust (after the headers) - which I plan to fabricate myself with some kind of carbon fiber muffler
                              - Light racing seats

                              I am not sure what we can do about the doors, windows and the sunroof (including motor).

                              In terms of an Alpha-N, I am interested but I live in Montreal and I am not sure where I can get someone to install and tune the car properly...I really love the CF intake. A surpercharger might also be a very good option...just waiting for a safe and reliable kit for our car.

                              Comment

                              Working...
                              X