Boxster weights
 

Sooo....AX season is almost finished and I'm already thinking of this winter's projects. One thing in particular that I've realized is that the Box sure does love losing weight to go faster. Currently my car (2000 986S) is around 2750. I'm not a Spec racer, but just for reference, what's the Spec minimum? What are some of the things Spec guys have done to pull weight out of the car?
The major things I've done:
Top and all it's stuff is gone
Spoiler is gone (I'm using Aerokit II lid and wing)
Carpet is gone in cabin and both trunks
Racing seats
Braille battery (absolute junk, it causes electrical issues)

what should be next???

BSX class is 2900 with driver (my car weighs 2710 empty)
BSR class is 2650 with driver (empty car is around 2470)

Boxster Spec Racing Official Website

It just depends on how far you want to go. Stock muffler, A/C system, stereo, carpeting all add weight. Eric523 has a great BSR build thread on Renntrack. His car is to-the-max and he really knows how to drive it.

Guess who just got a boxter?

Awsome link...thanks!

You said "racing seats". Remove the passenger seat, spare, radio, A/C, door panels...

you got a lot of the low hanging fruit.

you mentioned carpets; the sound deadening around the engine is HUGE (35lb+); it's 8" thick in some parts.

cat bypass pipes save 20lb over the OEM cat pipes.

racing muffler saves 45lb over OEM

(precision chassis works sells a BSR legal header back exhaust system that weights only 17lbs. the OEM is close to 90lb)

AC was much lighter than i thought it would be. 15lb for the compressor, 5lb each for the condensers & 4lb for the tubing (29lb total).

you mentioned the convertible top & all its 'stuff'. did you get the transmissions out? they're HEAVY.

obviously speakers & stereo stuff

side airbags = 5lb each
passenber airbag = 10lb
steering wheel / airbag = 12lb (if you install a racing wheel instead)

it's a slippery slope.....

Funny, the more I do, the more I forget that I've done! I've taken care of the exhaust: headers, Fabspeed bypass pipes, and a Borla muffler. I've also removed all of the stock sound deadener around the engine. The top transmissions and all hardware is gone, as are the clamshell linkages. It's now held in place with rubber tie-downs. I've also removed the rear trunk latch and cable, replacing that with aluminum pins. A CF or fiberglass hood may be in the future..
I plan to ditch the door & passenger airbags this winter, as soon as I can get a little quality time with a PST-II. The AC is also on the chopping block. If the PST-II has a disable feature for the secondary air injection, all of that will be gone as well.
I've heard that the rubberized undercoating is pretty heavy. Any thoughts on that?

My personal "rule" is that I can drive the car to and from autocrosses. That means keeping a VA inspection sticker. The folks I take it to aren't worried about the exhaust, but I can't have airbag lights on, and can't replace the steering wheel. I'm wondering what I could lose from the doors, but I think I'm stuck with the power windows, as I need some function there.

oh! you just reminded me: flash to the RoW program with the PST. this disables the secondary air injection system, allowing removal of the valves & the pump. that pump is HEAVY!! the RoW flash will also eliminate the second set of O2 sensors & the clutch start switch.

airbag light is easy: remove the bulb!

undercoating is appx. 40lb. if you figure out an easy way to remove it, do share!

one thing that caught my eye the other day was the windshield wiper apparatus at the cowl. HUGE chunks of metal moving those things! wondering if it can be simplified & have some of the framing removed.

so you've done all that & you're still at 2,750?!?!? i haven't put mine on scales, but it's a no option '99, which was listed at 2,800lb when new. i'd be shocked if it was over 2,600.

Takes 20min to remove the whole wiper assembly. I take it with me to the track and reinstall as needed :)


B

and makes it run like poo poo.. You can remove the pump and valves without the flash. Porsche sells the factory blockoff plates for $16 (euro cars don't have smog pumps) and our cars only use them during cold start.

I have tried the euro tune multiple times. Unless you "retune" their tune.. it makes less power.

brad -

really? how much less power? all i've ever run on my 3.4L is the RoW. wouldn't i trip a CEL?

as for the wiper assembly, do you know what it weighs? ;-) thanks

Where does this stop? The way I see it is that, unless you are going to dedicate a car exclusively to racing, worrying about the weight of wipers and small items borders on "automotive anorexia". :) You can remove everything from the car except essential items (including gallons of gas not needed for a specific run) but in the end, unless the car is a dedicated racer, you just have a stripped Boxster.

haha it NEVER stops! think about this: the ONLY two things that affect EVERY aspect of performance are tires and WEIGHT. a few hundred pounds makes a very, very noticable difference in lap times.

I promise I have built the lightest Boxster we will see based on a factory steel tub :)

1985lbs.. with ABS.. yes it is an obsession and anything under 2300lbs becomes VERY difficult. Yes, it is a dedicated AutoX car, and yes.. I could have easily pulled another 20-30lbs out by getting rid of the stock gas tank :) and going to fiberglass door skins.. oh.. and getting rid of the big cage in the car.

I believe I can build a 1925lb tub if I start with a bare tub :)

Insight? I believe you have a Roock conversion car correct? Do you have the cheap Chinese made headers?



B

i did my conversion myself. basics on the engine install:

- '99 3.4L w/ LN IMS, LN oil pump drive, & some new bits
- Stock 3.4L RoW program
- eBay Headers (1-5/8" primaries & 2" secondary)
- fabspeed cat bypass when at the track
- stebro race muffler
- custom intake w/ BMC air box
- Boxster MAF mounted in BMW 3.5" MAF housing (from BMW 540i)

what does it lay down to the rear wheels?

where did you find 1 5/8 headers? (cool)

the headers were dumb luck. i can't even remember who i bought them from. as for power? unknown, but at 4:55 in this video, you can guage output by comparing me to a 2008 Carrera S down the back straight at road atlanta. he pulls me, but not by much.

FYI, my car is a no-option '99 with about 250lb stripped out of it.

<iframe src="http://player.vimeo.com/video/31343135?title=0&amp;byline=0&amp;portrait=0" width="425" height="250" frameborder="0" webkitAllowFullScreen allowFullScreen></iframe>

Tough tell by the video, I don't have a reference point for corner entry/exit speeds

You need to dyno the car.. and have them run the O2 sniffer on it when they do it. I'm up to about 10 cars now (97-99) that have fuel pumps that cannot supply the fuel volume necessary to safely run the larger engines.

I promise (on my moms grave..lol) that you are leaving power on the table. A lot. You did the right thing with the larger intake tubes ans such, but the headers are still too small and a real tuners (there are only about 4 in the USA) need to be visited. Stay away from the "generic" tunes sold out there. The car needs to be dyno'd, logged and tuned!


B

any of these 'real' tuners happen to reside in georgia? :-)

BTW, the fuel pump in the '99 box is the same as the one in the '99 996. do you really mean to tell me that the pump in the early 996 didn't produce enough volume to support the OEM engine? surprising. what do you replace it with? the one from the 3.6L cars? direct fit?

thx for all the input.

No. The pumps are wearing out. Not failing 100% but cannot supply the volume at high RPM. Have you performed the Porsche volume test on your pump? Most people don't know about it and don't have a PSTII or PIWIS to test their volume.

None in Georgia. The closest guy to you is in Arkansas. He is the man behind the curtains on the Softronic stuff.

Dyno it on a GOOD dyno.. (Dynapack/Mustang/etc) something where they can load it and gather high quality 02 readings. The Dyno Jet pulls are good, but lack high quality 02 readings that someone from afar can use to tune properly.

The reason there are so little people? the software to interface is expensive.. I use a tuner locally that does damn near all the Porsches running pro in Grand Am. He travels, but he is not cheap. After 8hrs on the dyno one day, we managed 328 to the wheels with a 3.4. I believe there is more, but we ran out of money before we ran out time! lol

wow; that's big power. is that on race fuel?

correct me if i'm wrong, but it SOUNDS like you're saying i can dyno it here w/ data logging and have someone in a different state modify my program?

What's wrong with a stripped Boxster? I'd love a manual roof and more engine noise. Get the car light enough and it no longer needs the power steering that disconnects you from the road, you don't need the huge heavy tires and the lower mass makes the chassis and brakes more communicative as well. It not only makes the car faster, it makes it more fun in general.

It'll take forever to optimize it that way with all the back and forth of programs and trips to the dyno.

that's what i figured. w/ our forumula SAE setup in the mid 90's, we used an engine dyno room for HOURS to get a program dialed in. didn't know if there was some new tech that sped up the process.....

Correct on the dyno run locally, ship computer to tuner. It sounds like you did a nice job. 99% of the conversions that end up on my doorstep are poorly executed and the customer ends up disappointed :(

I can fix that :)

I'll be test fitting a new airbox that uses a stock Porsche filter next week (in a 986) :) I know it supports 300hp stock.. and it appears to bolt in ;)


B

One trip to a GOOD dyno (4 passes max) and a good tuner will see everything he needs to know. I recently was informed of another person local to me who popped for the 8k software. he is making good power with a "generic flash" for the 3.4 computers. Price was good also!

The tuner just needs good 02 readings!


B

It's an iterative process. No tuner gets it right on the first run. Plus, that's only WOT, there are hours and hours of driveability tuning in addition to multiple dyno runs.

Depends on the dyno, dyno operator and tuner. The good tuners will have maps that they start from.

We did a CaymanS.. we started with the more aggressive 3.6 STOCK tune. Pushed it to the car and then detuned the fuel as needed. Drives like no other CaymanS we have driven. Cam Timing was spot on. Took us 6 pulls total. Rolled it out onto the street and roasted the tires.

We are not tuning a fresh Motec/AEM/Bosch brain here (which can takes days) Porsche didn't leave 100hp on the table for all the engines!


B

6 runs though, trying to do it remotely would take a long time.

6 pulls because he didn't have a base "hot rod" tune for the CaymanS engine. He does now :)

I hear you, but a LOT of "tuners" do it this way.. a LOT.

GIAC
AWE
Softronic
just to name a few..

You buy their hardware and you down load generic tunes based on the mods you list. Want something custom.. they modify a tune they already have and email it to you. Push it to the car.. do a pull.. make change push it again.. make change push it again

Find someone who can download the stock tune from the car, make the changes and push it back without having to email back and forth with the "real tuner"

Those guy's are rare, but when you find them, they have really good base tunes for most of the stock displacement/stock cam'd engines, so 4 pulls and a good 02 reading is not far fetched. The guy I use pulls from a large database out of Italy. Sometimes we try a tune that is already modified, then modify it to work with our car.

There are really good Porsche tuners out there, but they are not typically on the web and they are not typically easy to get a hold of (they are busy)


B

anyone removed their power steering? fill the rack with fluid and loop the in into the out? save a few lbs, gain a few hp?

hadn't really considered it...

i am thinking about removing one of the radiator fan assemblies, though.

My engine bay insulation is starting peel off at the top opening. Is the same material that you pulled out? I am surprised that this came to forty pounds!!! Can get it all out with the engine in? Did you notice a big change in noise? I sometimes run with no storage box and no engine cover insulation. You hear everything....vibrating and buzzing

NO! that stuff is pretty light. the material i'm talking about goes around the sides of the engine hatch, on top of the hatch, and behind the seats. it's VERY thick; it's made of the same stuff the engine hatch insulation is made of. extremely dense & heavy.

anyone know what the ebrake system weights? lever, shoes, springs, cams & cables?

Ah the beige foam like the monster slab inside the cabin?? They put that down the sides of the engine bay as well?

Yeah that stuff could stop a bullet!

yes! it's actually over 8" thick in some spots. once you pull it out, you can clearly see the air intake / exit ducts that go to the inlets on the sides of the car.

without it, it's louder, but really isn't that bad IMO. still passes the wife test; admittedly my wife has a pretty high tolerance for NVH though....

How is it held in? Can you put it back in later?

it's glued down. to get it out, you will more or less rip it apart.

I suppose I shouldn't care, but I always get a little nervous when I make an irreversible change.

So Brad, where are the tuners? Everyone who tunes, I'm sure, thinks they are the bomb. So where's one to go to be sure he's getting what he's paying for?