Track forum general chit chat.

[Epoustouflant]

Looking for input and feedback on brake ducting kits
I'm looking to complement the GT4-S FRP lip group buy with a brake ducting kit. We are at 21 owners on the group buy as of now so this will go into production shortly.

I have heard great things about PureTechSweden's kit on various M platforms, they supposedly perform well as they oriente the back plate duct towards the center of the rotor to help heat dissipation.

MilehighM3 What do you think?
roastbeef Do you run ducts Mike?

They are well priced at around 150 US + shipping for the back plates, hoses and fittings extra, usually around 80 US.

As anyone here used their back plate?

They are interested to offer group discounts to complement the GB, and for anyone else running a duct'ed front lip.

Caveat is they will not fit with KW Clubsport 3 ways or similar coilovers with external reservoirs mounting on the strut.

[rhyary]

Originally Posted by slcook54

Finally going to an 18!?

Second set of 19" Forgeline

[roastbeef]

Originally Posted by Epoustouflant

Looking for input and feedback on brake ducting kits
I'm looking to complement the GT4-S FRP lip group buy with a brake ducting kit. We are at 21 owners on the group buy as of now so this will go into production shortly.

I have heard great things about PureTechSweden's kit on various M platforms, they supposedly perform well as they oriente the back plate duct towards the center of the rotor to help heat dissipation.

MilehighM3 What do you think?
roastbeef Do you run ducts Mike?

They are well priced at around 150 US + shipping for the back plates, hoses and fittings extra, usually around 80 US.

As anyone here used their back plate?

They are interested to offer group discounts to complement the GB, and for anyone else running a duct'ed front lip.

Caveat is they will not fit with KW Clubsport 3 ways or similar coilovers with external reservoirs mounting on the strut.

i don't have ducts because i haven't found a solution i'm happy with. i can tell you i'm not confident in 3d printed duct components after hearing about hard motorsport kits falling apart shortly after going into service.

[roastbeef]

Originally Posted by DRLane

I think you'll need more to drop 300lbs. That's a lot...

Net loss estimates (of course I may be wrong)
Battery: 50lbs
Akra: 50lbs
Brakes: 10-20lbs (would think that's on the high end)
Wheels: 5-8lbs a corner
Seats: 30-40 lbs per seat
Rear seats: ~ 20lbs

it is a lot, and please know my "300lb" was a five second guess. i went through a few pictures and got my old seats out today for some documentation! lets take a look- (all weights were rounded down to the nearest pound), number in the left column represents pounds lost.

37 - f/r essex cp5060/cp5040 brakes
10 - carbon driveshaft
8 - karbonius airbox
2 - rear seat fold releases
48 - rear leather/bolsters/head rests
48 - voltphreaks vph900 battery
5 - rear seatbelts
5 - rear center divider
27 - trunk trim, insulation, underseat carpet, rear floor carpet
5 - hvac filter delete (burger tuning cowl filters)
8 - misc. holes/titanium hardware throughout the car
6 - afe xpipe
38 - rear exhaust

That's all around 247lbs, conservatively.

[Epoustouflant]

Originally Posted by roastbeef

i don't have ducts because i haven't found a solution i'm happy with. i can tell you i'm not confident in 3d printed duct components after hearing about hard motorsport kits falling apart shortly after going into service.

These?

Link: http://www.hardmotorsport.com/hard-m...es-bmw-e9x-m3/

Or these?

Link: http://www.hardmotorsport.com/hard-m...t-race-inlets/

[roastbeef]

Not sure about the top one, looks like metal. Bottom one won't even fit our cars, it's for non-m cars with M3 bumpers. They had a club sport kit that was hot garbage. Their splitter mount is also trash. I have yet to hear of a high quality product from them.

[Epoustouflant]

Originally Posted by roastbeef

Not sure about the top one, looks like metal. Bottom one won't even fit our cars, it's for non-m cars with M3 bumpers. They had a club sport kit that was hot garbage. Their splitter mount is also trash. I have yet to hear of a high quality product from them.

Echoes what I heard about their door cards and pull strap handles. The PureTech backing plate is aluminium and powdercoated. I'll wait to hear back from 'em.

[E34nication]

Originally Posted by roastbeef

Not sure about the top one, looks like metal. Bottom one won't even fit our cars, it's for non-m cars with M3 bumpers. They had a club sport kit that was hot garbage. Their splitter mount is also trash. I have yet to hear of a high quality product from them.

Bought a few things from them in the past and I won’t go that route again. Poor fitment, poor finish and poor overall quality on all the items I bought.

I just bought the BW kit. Not installed yet, will update with impressions once on the car and tracked.

[roastbeef]

Their business model seems to be making a high profit margin once through 3D printed shit.

[Epoustouflant]

Originally Posted by roastbeef

Their business model seems to be making a high profit margin once through 3D printed shit.

Urgh, how those still exist in '21 is beyond me.

[MilehighM3]

Originally Posted by Epoustouflant

Looking for input and feedback on brake ducting kits
I'm looking to complement the GT4-S FRP lip group buy with a brake ducting kit. We are at 21 owners on the group buy as of now so this will go into production shortly.

I have heard great things about PureTechSweden's kit on various M platforms, they supposedly perform well as they oriente the back plate duct towards the center of the rotor to help heat dissipation.

MilehighM3 What do you think?
roastbeef Do you run ducts Mike?

They are well priced at around 150 US + shipping for the back plates, hoses and fittings extra, usually around 80 US.

As anyone here used their back plate?

They are interested to offer group discounts to complement the GB, and for anyone else running a duct'ed front lip.

Caveat is they will not fit with KW Clubsport 3 ways or similar coilovers with external reservoirs mounting on the strut.

Those look better than hard ms for sure. Personally I haven't found a solution that's worth a fraction of the asking price yet. Typically track junkies fab their own parts up and don't share, they just use them. I run the ST 380 kit up front with no backing plates. They still get hot, but I just adapt my driving style and find a more heat tolerant brake pad like carbotech or lately G Loc, with the latter being founded by ex members of carbotech.

[roastbeef]

This is the best duct kit I've ever seen. Designed by a time trial champ. I haven't done the legwork to figure out if they will come close to fitting my brakes.

https://www.jpmarketingllc.com/produ...-stoptech-st60

[DRLane]

Originally Posted by butte2butte

Rear seats are worth about 45 lbs if you pull out the backs, bottoms and side bolsters.

My front seat swap was worth 43 lbs per seat and I didn't do anything crazy light. Cobra nogaro with frp shells (not cf).

Going from a 220m wheel to a square apex 18" sm10 was worth 17lbs total. A 275/35 toyo RR set saved 8 lbs vs my 275/255r19 staggered set.

Pull out the loose trunk stuff/tire repair kit stuff for around 15 lbs.

the BMS cowl delete for about 8lbs up front.

Empty your wiper fluid tank (not putting this into the total though)

The 40ah antigravity battery should be worth 43 lbs.

Test pipes are worth about 8-10 lbs.

That's 225-230 lbs before you go akra rear section, different brakes or suspension.

Have you weighed all those things, and your car post? I've done everything on your list (albeit I run 305/275 which are undoubtedly heavier). I didn't make the dent y'all are anticipating. But only one way to find out!!! Rip, replace, and hit the scales

Good luck fellas. It's a fun exercise.

[DRLane]

Originally Posted by slcook54

That was my thinking exactly, I'm not being super specific or really chasing hitting 300lbs, but all those items mentioned above, plus a CF driveshaft should be getting pretty close.

I will end up adding a half cage too, so not really sweating it if I take out 250-300lbs and then put 50lbs back in.

I saw roastbeef quote the Essex kit savings is 27lbs.

My rough math was

Front seats: 90 lbs
Rear seats: 45 lbs
Battery: 40 lbs
Full Akra: 50 lbs
Titan7 TS-7 wheels and tires: 25 lbs
Brakes: 25 lbs
CF Driveshaft: 10 lbs
Suspension: ? Hadn't really factored that in.

That's 285lbs without really compromising too much (from my perspective)

Was just responding to butte. I have all those items done (even some of the specific brands) except for the akra rear. Didn't drop as much as I thought. Anyhow, it's definitely the right direction. Also, I believe most aftermarket suspensions are a net weight gain compared to stock.

[Bartledoo]

Originally Posted by MilehighM3

Those look better than hard ms for sure. Personally I haven't found a solution that's worth a fraction of the asking price yet. Typically track junkies fab their own parts up and don't share, they just use them. I run the ST 380 kit up front with no backing plates. They still get hot, but I just adapt my driving style and find a more heat tolerant brake pad like carbotech or lately G Loc, with the latter being founded by ex members of carbotech.

Yea, I'm just going to make cardboard templates and cut backing plates out of aluminum. I'll use spacers to get them nearly flush to the ID of the disc (with gap for expansion of course) and then rivet 2.5" aluminum flanges on for the ducting. The off-the-shelf options are expensive and none are specifically dimensioned for a PFC 372MM rotor.

[slowdown_dan]

@DRLane I didn't weigh the car pre and post each weight reduction item, but I weighed each part as it came off. My posted weights were within a few pounds, I'm not close to my garage notepad for a while to get the exact losses.

I have to imagine that weight reduction of each piece has to show up on the curb weight because otherwise wheres this phantom weight coming from?

[DRLane]

Originally Posted by butte2butte

@DRLane I didn't weigh the car pre and post each weight reduction item, but I weighed each part as it came off. My posted weights were within a few pounds, I'm not close to my garage notepad for a while to get the exact losses.

I have to imagine that weight reduction of each piece has to show up on the curb weight because otherwise wheres this phantom weight coming from?

I know, it's not magic. I'm just saying for some reason the weight doesn't fall off as much as I expected. I have more work to do and will get the car back on a scale for corner balance before season starts.

[DRLane]

Originally Posted by Epoustouflant

Looking for input and feedback on brake ducting kits
I'm looking to complement the GT4-S FRP lip group buy with a brake ducting kit. We are at 21 owners on the group buy as of now so this will go into production shortly.

I have heard great things about PureTechSweden's kit on various M platforms, they supposedly perform well as they oriente the back plate duct towards the center of the rotor to help heat dissipation.

MilehighM3 What do you think?
roastbeef Do you run ducts Mike?

They are well priced at around 150 US + shipping for the back plates, hoses and fittings extra, usually around 80 US.

As anyone here used their back plate?

They are interested to offer group discounts to complement the GB, and for anyone else running a duct'ed front lip.

Caveat is they will not fit with KW Clubsport 3 ways or similar coilovers with external reservoirs mounting on the strut.

I have these. Note they're designed for stock rotors. On my 380 ST some air blows on the inside rotor ring which isn't ideal. Never installed the hoses. I'm now going to AP so I'll likely ditch them all together. Not sure.

[roastbeef]

Inside the rotor ring is the goal.

[Davisca455]

Originally Posted by dparm

roastbeef be like, "I just removed 2 pounds of weight from the car, now I'm gonna put two pounds of food in my belly"

Hahaha!
You want to eat?
You gotta find a way to offset the dinner.
In the motorcycle racing world, it's a real thing.
Thru the early to late '80s I worked on a number of the top AMA Class C dirt track teams making exhaust systems.
The teams would come out west for the Ascot, San Jose and Sacramento rounds and they'd make an early stop at our shop in Davis to get the latest equipment.
One of the top privateer teams at the time was run by a guy named Eddie Atkins, and I was making him a new set of headpipes, reverse cone megaphones and "Boomboxes" for the San Jose and Sacramento Mile races.
We wrapped up early and I asked him if he wanted to copy some of his steel brackets in titanium?
He says "No thanks, I have a Titanium rider."
He wasn't kidding either, Jimmy Filice couldn't have weighed more than 120 lbs. Dude was FAST!

*Edit*
Rider on the right, 17z, is Jimmy Filice.
That's Mert Lawwill (On any Sunday) next to him.
For reference, Mert is like 5'5".

[MilehighM3]

Originally Posted by Epoustouflant

Urgh, how those still exist in '21 is beyond me.

You may also look at these

[roastbeef]

i'm not sure how you're supposed to mount the scoops without a mounting surface. secondary to that, too much of a gap between the rotor and duct exit.