coss1600

Hey guys, my car is consistently coming in overweight at 2750. I have identified the following items where I shave the weight. Is there any other obvious spot I am missing? Car looks stripped but it does have the wiring harness. I heard that is only about 20lbs.

Oem muffler to be replaced -20
covid weight -20

other weight
factory wiper linkage? 10?
seat bracket 5?
wiring harness 20?

any other obvious area?

thanks

BFT3.2

It's hard to recommend what to remove if we dont know what you have already taken out. You might have these out already but here's some heavier items off the top of my head if your searching for pounds

OEM muffler, CATs, front and rear bumper bars & hardware, I believe a photo of your trunk showed a Accusump? Of course all of the AC components, radiator fans, air pump, engine fan, HVAC

txhokie4life

factory roof vs fiberglass?
factory windshield vs lexan
how stripped are the doors, frunk and trunk of excess metal
battery type/size
did you keep any/all of the radiators/fans?

Nickshu

Removing the crash bars from under the bumper covers gets rid of some weight. It does increase the risk of tub damage in an impact but many I have talked to do it. Also note this weight is at the ends of the car far from the center of rotation, which is probably a good thing.

A lightweight battery saves quite a bit of weight, if you still have a regular standard battery. Note if you are running in PCA the rules state the battery must weight at least 10 lbs which eliminates pretty much all lithium batteries. The Odyssey PC680 is a common choice. It weighs about 14 lbs not including whatever mount you use, I have the Rennline mount.

My car is pretty well stripped and I am at about 2700 including me and subtracting fuel weight. I would love to find the other 50 lbs but I feel like I have so many other things I need to work on as a driver / new club racer, the extra pounds probably won't matter at this point LOL.

coss1600

Thank you for the suggestion. I totally forgot about the windshield. I will be changing it to Lexan as the windshield has multiple chips anyway. I do have a lightweight top and lightweight battery already.

Goal 100lbs
WFH weight -20lbs
Replace OEM mufflers -20lbs
Lexan Windshield -8lbs?
Windshield wiper system?!? I live in CA, probably don't need the wiper

I guess I will be around 2700 like you Nick

ace37

A lot of people could take more out of the doors. The battery is easy, and the clutch and flywheel help too.

In case it gives you ideas, I have a build thread that covers a decent amount of what I did in my car build. (I had kids and that took more and more time so it started as my project and largely became my local shop’s project. Oh well.) My car can get to weight with 1/4 tank, me at 185, and no cool suit but an accusump that I may remove.
https://rennlist.com/forums/spec-box...d-cooling.html

coss1600

why you removing the accusump?

ace37

I put it in after my OEM 70k mile engine lunched itself after just 10 hours of trackday use on street tires. I was concerned that my local track could be harder on these motors than most tracks.

Since then more 986s have come and I’ve talked with one owner who has put over 100 hours on his Boxster at the same track without an accusump, and others have also had good luck. So I don’t think my one-off failure was necessarily anything related to oiling or my local track being hard on cars in some unique way. I think I just drew a short straw is all.

Because of that, it might make sense to eventually pull it for weight. But since I can currently meet weight and it probably doesn’t hurt the car in any other way related to performance, eh. We’ll see. The added oil volume keeps it cool too I suppose.

If later I want to add a cool suit and am looking hard for pounds to shave, that’s when I’ll give it a lot more thought.

coss1600

Interesting. I am looking for as much protection as I can, I am even thinking adding another oil cooler in the trunk despite the weight. I might be able to route it to the same line as the accusump to save some lines. Where are you finding the weight in the door? Removing the latch assembly or cut the crash bar off?

Oh yeah my 2750 weight is with an empty cool suit gear. I am guessing the water and stuff add 25lbs.

Nickshu

Data on an Accusump for a SPB is mixed. I have seen some that shows it helps and some that shows it does not. I think the choice is deep sump vs accusump. Accusump adds weight and complexity and makes oil changes more of a PITA. Deep sump adds the risk of hitting/breaking the lower hanging oil pan if you drop a wheel off. Pick your poison. Or do both, which may nor may not matter.

My car was built with a Motec C127 system that tracks oil pressure, among other things. Running a deep sump and the stock paper filter (no accusump) I see no more than slight oil pressure drops in my data, or all of the PO's data that came with the car. It also appears this may be engine-specific, I have heard some engines are better than others, luck of the draw.

RennPart

The really easy things to remove weight that sometimes get overlooked are the heavy rubber trunk/frunk and door gaskets. I just weighed the frunk gasket and its about 6lbs!

It all adds up!

The air pump and secondary air injection system are another 8-10lbs and often overlooked as well. We sell the block off plates to remove this system.

secondary air delete kit

--Aaron

ace37

I took the bars out and cut away much of the metal in the door. I have photos in the thread somewhere if you want to see exactly. My cage has side intrusion protection and the door bars would interfere and wouldn’t do much of anything compared to the cage anyway. The door bars are fine for DE/TT but I would not trust them in a racing setting - IMO that should be replaced as a part of your cage design. Lots of well established ways to do that. I like a protruding X over a flat X or the NASCAR solution.

Basically though you can just read the rules closely, and anything that you can remove or replace to drop weight is something you ought to plan to do. As the last poster said, even the weatherstripping adds up - I found it surprisingly heavy.

I have a deep sump and the accusump, and I have an oil cooler but no third radiator. I’m at high altitude in the desert and have never had oil temperature issues, but my water will eventually get a bit hot if I don’t start short shifting by ~500 rpm in an endurance race setting (minimum 90+ minute sessions). Never an issue at all in sprints, and at lower altitudes my cooling system will have more air to reject hear with so it should perform more effectively. I also run a trans and PS cooler to extend the life of those components.

Lemming

See rule 7B with respect to the crash bars. With this rule in mind, I was able to remove the drivers side, but not the passenger due to my cage build.

B. All interior items and insulating material may be removed except where otherwise noted. Doors may be gutted, except factory door beams must be intact or protruding intrusion door bars must be added to the cage.

trygve

Speaking of the factory "door beams" or "crash bars" -- I never got around to removing mine, and when my car was hit on the side pretty badly at the end of last season (along the passenger side door, b-pillar door jamb, and rear quarter panel), the presence of the door beam may well have prevented the hit from impacting the roll cage main hoop and certainly the side bars of the cage.

The door beam stayed straight while the door panel above it caved in (and the lower part to a lesser degree), and this may have reduced the deformation of the b-pillar. Hard to know for sure. But the door never came close to hitting the roll cage side protection bars, and the b-pillar just barely avoided hitting the main roll hoop. I have a big repair to do, but at least the cage is fine.

So, I guess I'm a fan of keeping the door beams! (And, OF COURSE, ALSO of the cage having its own protruding intrusion side bars.)

coss1600

Ouch sorry to see the damage. Wow I actually still have the entire pocket to hold my gloves on the door.