HP Autowerks, Inc. Project 135i N55 Begins

[GaryS]

^^ Thanks!

[Novator]

Originally Posted by HP Autowerks

It's really apples and oranges. 3-piece vs single piece. Forge vs cast. I-beam vs web spoke design.

3-piece wheels allow any offset, inner and outer rim half combo, color and finish. single piece you are stuck to what you get. With the 3-piece wheel you can actually get the perfect offset and run 245-255 front tire without the need of -2+ of camber. I believe the +38 front offset on the Apex wheel is too aggressive and left too much of usable room on the inside(wheel to strut).

I-beam in my opinion(probably many others racers and engineeers will agree as well) are far stronger and give maximum stiffness then the web design. Web design is too complex to achieve consistant casting and often stress raisers are found at the intersection of the webs, unless you forge it of course.

With all that being said, ~$300 is not a bad price for a of low cost track wheel. If you bent one, just buy another.

Add: What I didn't mention is that stiff wheels also give more positive steering response and better corner entry characteristics. Any type of delay or lag is bad.

I would like your opinion on ARC-8s. I don't track my car often except for an occasional autocross (maybe one every two to three months), but I would like to do more events whenever I upgrade my suspension and or brakes. My question though is since you mention the design and manufacturing process is much different than Forgeline's will ARC-8s be strong enough for daily driver use on regular roads (bumps, dips, occasional pothole and scarred pavement)?

EDIT: Found this link, all questions answered: http://www.planet-9.com/porsche-tire...g-methods.html

Sorry for the stupid question

[Eddy@ApexWheels]

Originally Posted by Novator

I would like your opinion on ARC-8s. I don't track my car often except for an occasional autocross (maybe one every two to three months), but I would like to do more events whenever I upgrade my suspension and or brakes. My question though is since you mention the design and manufacturing process is much different than Forgeline's will ARC-8s be strong enough for daily driver use on regular roads (bumps, dips, occasional pothole and scarred pavement)?

EDIT: Found this link, all questions answered: http://www.planet-9.com/porsche-tire...g-methods.html

Sorry for the stupid question

I'll chime in as I know Harold has not run a set of ARC-8 wheels yet for street or track use, and there's some misinformation developing that I'd like to clear up.

The ARC-8 can absolutely can handle the street. The ARC-8 was designed to meet the width, offset, and weight requirements of track drivers, but they're not a track only wheel. Some other manufacturers have developed a "track" wheel that truly did not meet the strength requirements of the street, and this seems to left many people with the assumption that all track oriented wheels cannot handle the street.

Although the dimensions/specifications of the ARC-8 was designed to fit wider rubber then the stock wheels, they still meet/exceed the strength and testing requirements of street wheels.

The ARC-8 wheels are flow-formed, not just regular cast. There is nothing "too complex" about the mesh design of the ARC-8 wheel that causes casting inconsistencies. I have no idea where an assumption like that came from, but it's a generalization that should not be used to describe the ARC-8 wheel. There has never been a single failure or issue regarding the strength of the spokes or overall design. The wheels weren't just tested for stress in a computer simulation like many USA made forged wheels, or not 3rd party tested/certified like numerous other manufacturers. They were each run through three rounds of crush testing in house as the design was tweaked, and then final crush testing in Japan to receive true VIA certification, with registration numbers to prove it.

It really is an apples to oranges comparison, because the Forgeline's are a premium wheel with a price to match. Custom always costs more. But that doesn't mean a flow-formed wheel that's been priced aggressively at $1200~ does not meet a users strength needs, as both the testing and real world use of these wheels for street and racing use have proven their strength and design.

Do note: the goal of light-weight forged wheels is not to make them stronger then needed. It's to make them as light as possible while still meeting a certain minimum strength rating. They designed that wheel like every other wheel to be only so strong, and then focused on reducing material weight from there. 3 piece wheels are also the least ridged wheel construction. It's a trade off for ease of customization regarding offset/caliper clearance by changing centers and barrels. Since they are bolted together, they lack the rigidity of one piece wheels. Even Forgeline pushes their monoblock wheels as their stiffest/lightest wheels, for good reason.

Harold at HP Autowerks was sent a front sample wheel, and picked up a rear wheel of the APEX ARC-8 for testing, as he planned to run the ARC-8 wheel on his project 1 series. The front offset was too aggressive for his specific application. They were originally designed to run wide extreme summer tires in a competitive racing or autocross application, which would always run aggressive camber anyway. The low offset was needed to avoid the use of spacers in those applications. They were produced in a small batch in that offset. I hope that the sample wheel at least provided a useful tool for selecting the offsets on the Forgeline wheels.

Luckily a new version of the 18x8.5" ARC-8 will be coming out in a higher 1 series specific front offset that will allow it to fit street oriented applications while still running wider tires. This will give owners two front wheel options to pair with the 9.5" wheels that already have the perfect offset for wide rear tire use, on both stock and modified 1 series applications.

[HP Autosport]

Flow-form or not, it is still a form of cast process, and I just call it generalize them all as cast. Whenever you cast a wheel, liquid metal is allow to cool, the more complex the design the more likely you will have inconsistent castings during the cool down process. Any race car engineers here are welcome to comment...

Eddy, I still have plans to run your wheels for track duty, either running very aggressive negative camber(-1.5 is max without taking away too much tire life, -2 significantly reduce tire life) or change them at the track. The other alternative is to wait for a less aggressive offset, maybe in the range of +42-45.

[Eddy@ApexWheels]

Originally Posted by HP Autowerks

Eddy, I still have plans to run your wheels for track duty, either running very aggressive negative camber(-1.5 is max without taking away too much tire life, -2 significantly reduce tire life) or change them at the track. The other alternative is to wait for a less aggressive offset, maybe in the range of +42-45.

I'll keep you in the loop on production in the coming months regarding the new fronts. You'd probably prefer the more conservative fit, and use spacers if needed, although you've been pretty good about keeping the lower spring perch above the tire on your projects, thus buying more inner clearance.

[vitig]

Originally Posted by HP Autowerks

Just waiting for the new Forgeline GA3R 3-piece wheel to show up.

Stoptech's 355mm six-piston front and 345mm four-piston rear Trophy Sport Big Brake System should be on before the track day as well as the stock set-up is probably not up to the abuse we will be throwing at it even with upgraded Hawk DTC-series race pads and Castrol SRF high temp brake fluid.

Do you install steel brake lines?

[HP Autosport]

Originally Posted by paintpro21

I'll keep you in the loop on production in the coming months regarding the new fronts. You'd probably prefer the more conservative fit, and use spacers if needed, although you've been pretty good about keeping the lower spring perch above the tire on your projects, thus buying more inner clearance.

We have not run into any issues with the lower spring perches not clearing the wheel or tire on most if not all the project cars we have done here. Then again, we rarely install none true coilover systems nor do we lower these cars more than 1" up front. With a proper offset, no wheel spacers or aggressive camber would be needed.

Originally Posted by vitig

Do you install steel brake lines?

The SS brake lines come with the Stoptech BBK. The stock lines do a great job for day to day use and you wont' see a huge change in pedal feel by going with SS lines at all. For track duty, SS lines can stand up to the abuse and heat much better.

[j1gzca]

Harold, if you don't mind sharing the info. What spring rates did you choose to pair with the TCKs?

[oman135]

Nice ! More pic please

[HP Autosport]

Originally Posted by j1gzca

Harold, if you don't mind sharing the info. What spring rates did you choose to pair with the TCKs?

400F and 800R

[HP Autosport]

The latest upgrade is the HPA Rear Quick Change Spring Kit.

This kit allows the user to change spring rates at home or the track in minutes, without disconnecting the lower control arm and without performing another wheel alignment as long as the ride height remains the same.

This kit not only allows you to change your springs very quickly, it also allows you to adjust the ride height of the vehicle with the springs installed. YES! With the springs installed. No need to remove the springs! Most E82/9X coilover kits on the market today, you must unload the spring tension to adjust the rear ride height, but not ours!

What is in the kit:

HPA Rear Ride Height Adjusters
BMW Sealed Radial Thrust Bearings(used on the top of the main spring)
Swift Main and Helper springs
Swift Thrust Sheets(use at the lower portion of the spring, between the helper and the control arm)

[brracing]

Harold and team....since you opened this thread about the build of the N55 and the 1M....are you going to -
(1) go wide body on the front to equal the track width of the 1M?
(2) flare the rear at all to equal the look of the 1M?
(3) do a quad exhaust like the 1M?
(4) do any more body weight lightening, or leave the full interior in?

Interested in the project....good luck, and enjoy
Bruce
BRracing

[HP Autosport]

Originally Posted by brracing

Harold and team....since you opened this thread about the build of the N55 and the 1M....are you going to -
(1) go wide body on the front to equal the track width of the 1M?
(2) flare the rear at all to equal the look of the 1M?
(3) do a quad exhaust like the 1M?
(4) do any more body weight lightening, or leave the full interior in?

Interested in the project....good luck, and enjoy
Bruce
BRracing

Bruce,

(1) go wide body on the front to equal the track width of the 1M?

No, I may just pick up the 1M when it comes out.

(2) flare the rear at all to equal the look of the 1M?

See above.

(3) do a quad exhaust like the 1M?

I don't see any performance gains from doing that.

(4) do any more body weight lightening, or leave the full interior in?

M3 suspension parts, TCK DA's, wheel/tires and our lightweight battery kit already took decent weight off of the vehicle. Double sided carbon hood and trunk will further reduce weight. This is a street car so no further weight reduction will be done.

[HP Autosport]

The latest upgrade to HPA's Project 135i:

Front Stoptech Trophy Sport Big Brake Kit.

It's front brakes only but here you go!

Front BMW 135i OEM:

12.2 lbs oem caliper with pads(6500 miles)
21.6 lbs oem rotor(6500 miles)
2.0 lbs oem caliper bracket/mount

*The oem components may be a bit heavier when new

Front Stoptech Trophy Sport:

10.4 lbs Stoptech Trophy Sport with pads
17.6 lbs Stoptech rotor(355 x 32mm, larger in diameter and thickness than oem)
1.2 lbs Stoptech caliper bracket/mount

You are looking at an unsprung weight savings of ~6.6 lbs per each front corner of your 135i. You'll notice that there was 4 lbs saved on the rotors alone, if the rotor size and thickness had been the same as an OEM rotor, the saving would have been even greater.

[HP Autosport]

Originally Posted by brracing

Harold and team....since you opened this thread about the build of the N55 and the 1M....are you going to -
(1) go wide body on the front to equal the track width of the 1M?
(2) flare the rear at all to equal the look of the 1M?
(3) do a quad exhaust like the 1M?
(4) do any more body weight lightening, or leave the full interior in?

Interested in the project....good luck, and enjoy
Bruce
BRracing

Bruce,

Just a quick update for you. We just placed an order for the new 1-series M coupe so our project 135i will be up for sale very soon.

[aisthetes]

Originally Posted by HP Autowerks

Bruce,

Just a quick update for you. We just placed an order for the new 1-series M coupe so our project 135i will be up for sale very soon.

HPA + 1M = Time Attack Domination. Deadly combo.

[crex]

Originally Posted by HP Autowerks

Bruce,

Just a quick update for you. We just placed an order for the new 1-series M coupe so our project 135i will be up for sale very soon.

Can I get dibs on the stock suspension of the 1M?

[vwrefugee]

We just placed an order for the new 1-series M coupe so our project 135i will be up for sale very soon.

That was a short "project". Where's the aforementioned GIAC tune, larger intercooler, Recaro seats, etc?
Actually, I don't blame you for jumping to the 1M, wish I could do the same.

[GaryS]

Originally Posted by HP Autowerks

Bruce,

Just a quick update for you. We just placed an order for the new 1-series M coupe so our project 135i will be up for sale very soon.

Is there still going to be a HPA 135i radiator?

[HP Autosport]

Originally Posted by GaryS

Is there still going to be a HPA 135i radiator?

Yes, it is just taking a bit longer than expected to get production going.

[M_Anthony]

Originally Posted by HP Autowerks

Out comes the oem BMW battery, which weigh 41 lbs. In goes the 15 lb Braille battery with HPA's Braille battery tray weigh in at just 17 lbs.

***21 lb Braille Battery pictured***

I really, truly do not understand why people pay the 100%+ markup on Braille batteries. They are exactly the same batteries as East-Penn Deka, aka the original manufacturers. Braille just takes them, slaps a new label on them, and charges twice as much. Don't encourage this crap, buy from the source!

Also, and this doesn't apply here since this will be a show/track car, but I don't understand why anyone is putting a LW battery in this car. Deka 15s do not provide enough CCAs for our cars and will go dead in the winter time. I've experienced this numerous times, which is why I don't run them in anything but track cars.

Also, it's not as though you're reducing unsprung weight, weight above the center of gravity, or even weight on the front end of a nose heavy car.

[HP Autosport]

Originally Posted by M_Anthony

I really, truly do not understand why people pay the 100%+ markup on Braille batteries. They are exactly the same batteries as East-Penn Deka, aka the original manufacturers. Braille just takes them, slaps a new label on them, and charges twice as much. Don't encourage this crap, buy from the source!

Also, and this doesn't apply here since this will be a show/track car, but I don't understand why anyone is putting a LW battery in this car. Deka 15s do not provide enough CCAs for our cars and will go dead in the winter time. I've experienced this numerous times, which is why I don't run them in anything but track cars.

Also, it's not as though you're reducing unsprung weight, weight above the center of gravity, or even weight on the front end of a nose heavy car.

This is a car that is daily driven and at times sit either at the showroom or the shop for weeks. It has seen no track events so far although HPA has plans to take it to a track day for a shake down session. So far the 15 lb Braille battery given us no issues even with a week or two spent parked.

One way to increase the the acceleration and cornering capability of a vehicle is to reduce its mass, the light weight battery is just one of the components we chose to replace here. Although it is not a weight above the center of gravity(do you know where the center of gravity of the 135i actually is?), it is away from the center of gravity. Weight reduction furthest away from the center of gravity will have the greatest affect on response. To the engineering type this is the moment of inertia(correct me if I am wrong).

Originally Posted by BimmerEngineer

Why mention just a measly 6.6lbs of unsrpung weight? It takes over 150 lbs of unsprung weight to really gain any performance increase >> (that's shorter braking and better cornering).... Reducing 75-100 lbs might make your car accelerate SLIGHTLY quicker (by a tenth or two) but it won't be noticed.... Just two cents worth....

Did you mean to say 150 lbs of sprung weight? Even at 100 lbs of sprung weight there will be measurable performance increase both in acceleration, deceleration and cornering. 100 lbs may not mean much down the 1/4 mile drag strip, but put the car on a 2.4 mile, 15 turn circuit, you will the additional weight really hurts the lap times.

We simply stated the unsprung weight reduction of the Stoptech Trophy Brakes, another benefit would be less rotational inertial. Perhaps you are more interested in the reduction of 15-20 lbs of unsprung weight at each corner of the vehicle with the use of lightweight wheels and none RFT tires or the the Koni DA coilovers with Swift springs and aluminum M3 control arms.

With all due respect, if you are a BMW engineer would you not agree every pound of weight, unsprung or sprung that doesn't need to be accelerated, decelerated and go around a corner will make the car quicker?