HP Autowerks, Inc. Project 135i N55 Begins

[HP Autosport]

The 135i BMW Should Have Made + More
BMW finally got the hint and created the 1M car that we have all been asking for but we still believe that the 135i model is still an extremely capable chassis and we are going to push the limits with our new project car.

We have already brought you the first N55 Berk Technology exhaust and that was only the tip of the iceberg.

As some of you may or may not know, HP Autowerks was the first to figure out that most of the M3 control arms were a direct bolt on for E82/90/92/93 way back in 2008 and were the first to market this upgrade. We did non-stop R&D on our 335i shop car and we will be doing the same with our N55 135i so that we are able to offer our customers and the 1addicts community the best options for increasing performance.

Our car will have every possible upgrade and it will be entirely performance oriented. The first aspect we will tackle is suspension. We will be using our entire M3 control arm kit to get better suspension geometry. Then we will couple this with TC Kline’s Double Adjustable Coilovers but take it a step further by using SWIFT thrust sheets and custom rate SWIFT springs which are the best on the market right now. They have shown their superiority in individual unbiased testing.

We will then move on and tackle the driveline with Quaifes new 1 series application. We had enormous success with the Quaife ATB in our 335i and we are chomping at the bit to put it in our 135i. We are going to need it with the extra power that we will be packing.

The engine already has the Berk free flow exhaust to which we will add other engine products that we up our sleeve. Among some of the planned upgrades are a GIAC tune, bigger intercooler, HP Autowerks performance filter (first filter out for the N55) and a few other goodies.
We were also the first to figure out that the M3 strut tower brace works on the E9X non-m’s. We will be working on modifying the M3 brace to work on our 135i and offer it as a product in our shop.

Although the E82 chassis is already 250lbs lighter it is still too heavy of a car. We are shedding weight by adding carbon fiber bits from iCarbon which include a carbon vented hood and carbon trunk. We will also add a carbon fiber front lip and performance diffuser although weight savings on those two pieces will be negligible. A set of leather with suede centered Recaro Sportster CS, the same seats that BMW calls the Performance seats offered in Europe, will adorn the interior. We will also install a Braille 15lb battery along with the HP Autowerks CNC’d battery holder.

Even though the 135i comes with factory Brembo brakes, they are not on the same level as the Gran Turismo brakes that Brembo offers on the aftermarket. While the GT Brembo kit would be a great upgrade we will do one better and fit our shop car with a Stoptech Trophy BBK, the same kit that we pioneered in conjunction with Stoptech on our 335i.

Overall, we are looking to lead the way with this car just as we did with our E90. This is a project that we have been looking forward to since the 135i came out and are excited to create the car that should have come from the factory. We believe that the M3 suspension components, LSD, TC Kline D/A coilovers, and weight savings combined with our power upgrades will give us an end result that we believe will give the new 1M a run for its money.

***The M3 Strut Tower Brace Kit does fit the 135i with some tweaking. Getting to your camber plates and rebound damping adjustments are so much easier now***

***M3 anti roll bars and rear subframe bushings not pictured***

[bradford]

Looking forward to the details on the M3 brace, Harold.

[ES BMW]

Great news! Can't wait to see what all you come up with.

[Buzz135]

Harold dont forget about the front and rear sway bars and subframe bushings

[ILMOSTRO]

Definitely eyeing the entire M3 control arm kit, TC Kline’s Double Adjustable Coilovers, SWIFT thrust sheets and custom rate SWIFT springs + M3 Strut Tower Brace Kit.

Cost for these goodies installed at your Santa Barbara shop? I could make a weekend trip of it up from San Diego.

Thanks Harold.

[aisthetes]

Originally Posted by BR3CK

Definitely eyeing the entire M3 control arm kit, TC Kline’s Double Adjustable Coilovers, SWIFT thrust sheets and custom rate SWIFT springs + M3 Strut Tower Brace Kit.

Cost for these goodies installed at your Santa Barbara shop? I could make a weekend trip of it up from San Diego.

Thanks Harold.

Now that would be a memorable SB getaway, Breck! That's my dream spec list, btw.

You'd probably have to give them all day on a Friday to get the job done, and allow time for them to drive the car up the street to get an alignment at their recommended shop. Then you may as well get a hotel room and hang out the next day or two, or come in Thurs night to avoid morning rush hour.

It took HPA roughly 1/2 day to do the M3 control arm kit and alignment on my car. The quality of work and level of customer service is first rate. Plus, you can walk over to the performance shop while the guys are wrenching at the repair shop and hang with Harold and T.C. Kline himself a bit. I'm sure they'll have something cool hanging around to drool over.

Your car will be an animal with the setup and really allow you to use your Dinan STG II power to the fullest on track.

[aisthetes]

Oh, I'd also consider adding the M3 rear subframe bushings at the same time. It's one of those "while you're in there" jobs that'll save you a lot of labor costs if done together. Talk with Harold and T.C. - it's a must do to get the result you're after, particularly with the level of modification and quality of parts you're selecting.

[ILMOSTRO]

I'm down. I just sent Harold a message with a few questions.

I'd definitely make a weekend out of it with Alyssa. We'd drive back through Malibu's canyons, etc. Should be sweet as I'm planning on doing some track driving as well. I don't want to ruin the drive on the streets (not that it's great anyway).

How does yours feel on the street? I live downtown SD, not in a smooth suburb. Not sure where you drive mostly.

[aisthetes]

Originally Posted by BR3CK

How does yours feel on the street? I live downtown SD, not in a smooth suburb. Not sure where you drive mostly.

I didn't notice any change in ride quality by switching to the M3 control arm kit, but the camber plates did contribute to a bit more noise and less dampened feedback through the steering wheel, both of which I like. Plus, you'll be able to dial out the damper stiffness with the D/As, so it probably can be tuned to be more compliant than stock.

[marcus]

***The M3 Strut Tower Brace Kit does fit the 135i with some tweaking. Getting to your camber plates and rebound damping adjustments are so much easier now***

What kind of tweaking? Tweaking as in I can do it myself?

[cpt97m3]

Originally Posted by BR3CK

How does yours feel on the street? I live downtown SD, not in a smooth suburb. Not sure where you drive mostly.

If you are worried about ride quality, just mention that to Harold and make sure he will get you the right spring rates. You don't want to go too stiff if ride quality is a concern. They can be setup to ride fine on the street, but still have a massive improvement over stock. You can run the compression damping soft for the street, and stiffen it up for the track. The rebound is probably best just set at optimum and left alone.

Let us know when you get it installed. Hopefully before the AutoX on the 18th.

[ORIGIN M.]

Subscribed!

[ILMOSTRO]

Sounds good. Skipping the M3 bits for now but I'm on the M3 Strut Tower Brace and TC Kline coilovers as soon as HP has them in stock. I hope before the next autocross on Sept 18th.

[HP Autosport]

Originally Posted by bradford

Looking forward to the details on the M3 brace, Harold.

Originally Posted by My E90

Great news! Can't wait to see what all you come up with.

Originally Posted by marcus

***The M3 Strut Tower Brace Kit does fit the 135i with some tweaking. Getting to your camber plates and rebound damping adjustments are so much easier now***

What kind of tweaking? Tweaking as in I can do it myself?

The 1-series strut tower brace kit will be ready for sale in a about a week or so.

The piece attaches to the firewall has been modified slightyly to fit the the 1 series perfectly. Both CNC billet style and new casting have been considered but will raise the cost of the kit by a significant amount, we finally settled on just modifying the oem M3 unit with the jig we made during our prototyping.

[HP Autosport]

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***

[ORIGIN M.]

[MINI135i]

Curious how the N55 will handle an aggressive day at the track in stock form?

Have you guys had chance to run it yet and see if it handles heat better than the N54?

Looks like a great list of suspension mods overall, should be a great set up!

[HP Autosport]

Originally Posted by MINI135i

Curious how the N55 will handle an aggressive day at the track in stock form?

Have you guys had chance to run it yet and see if it handles heat better than the N54?

Looks like a great list of suspension mods overall, should be a great set up!

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.

[TheMadDutchman]

Those are going to look great!

[HP Autosport]

Forgeline GA3R wheels are here! Tire choice is, of course, Michelin PS2's!

[GaryS]

It looks like you fit the same size tires on these wheels that the APEX Arc-8 can fit. I assume these wheels cost 3-4 times as much. Can you give a little summary comparison?

[HP Autosport]

Originally Posted by GaryS

It looks like you fit the same size tires on these wheels that the APEX Arc-8 can fit. I assume these wheels cost 3-4 times as much. Can you give a little summary comparison?

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.