Winter update – 2.22.15


We have been busy cranking out turbo BMW’s. We have over 35 E46 M3 kits out there, and we are currently assembling and finalizing two Stage 4 cars at the shop, along with our first S54 Z3 kit. A stage 3 car is down at Technique Tuning in Florida for calibration development with larger ID1000 injectors. We ran an 8 second 1/4 mile with my E36 M3 at the end of last year, and I sold the car to a customer that will continue to push it further. This will allow us to focus on pushing the E46 development further rather than getting distracted between the two cars. It was a long, rewarding road with the e36. First in the 9’s, first in the 8’s! Sad to see her go, but it was a necessary progression.

8 second compilation video, 1/2 mile roll race and other media:

If you follow us on Facebook or Instagram, some of you have already seen the transformation of my E46 M3. Last year we installed a bimmerdiffs upgraded differential, along with all new poly bushings all around. We also performed the subframe reinforcement before buttoning it up. The car currently has the entire interior removed to begin the NHRA roll cage fabrication (complete with parachute and window net). The car is also getting a driveshaft loop and battery cutoff per the rulebook. While the cage is doing in, I am also installing a carbon trunk, carbon diffuser, and carbon roof. We also fabricated a larger 3.5″ single exhaust (that can be used with any of our different kit levels, and it has options for a single exit using a carbon diffuser, or quad exit using an oem style diffuser).

We suffered numerous 6 speed transmission failures with the e36 running an e46 M3 getrag box. They don’t stand a chance when the car makes almost 900 ft/lbs of torque!

I have a 6 speed dog box getting built by Samsonas Motorsport for my car. It uses an OEM ZF E36 transmission case with all new gears and internals, along with a CNC’d spacer to make the case the correct length for the additional gears.I also have a new twin disc clutch from Comp Clutch to try out in the car. We will have feedback shortly. I have had it for a while, however I am waiting for the new transmission to arrive so I can install it at the same time. I also have a Tilton carbon triple disc clutch for when things get serious and the built motor goes in later on this year.

We are going to keep the stock motor in the car and race it as-is with our current Stage 2 hardware, however it will be using our flex fuel system(Yes, we are still working on it!) running E85. My car has over 30k miles with our kit, and I have no issue driving it anywhere. We drove the car ~1400 miles to PRI and back this year and I have been to florida a few times with it. We also thrashed on it when we went to Bimmerfest, Willow springs track day, and MFEST. Still running strong!

At the same time, we are also assembling a built motor for my car, so that once the flex fuel development is completed, we can swap in the built motor and Stage 4 components. Exciting times for sure!!!


There have been some bumps in the road with our kits, but nothing that hasn’t been remedied. We had a few of our first intake plenums split at one of the welded seams. The first four cars were the only ones to have that issue, and they have all been repaired by now.

The major issue that we are still dealing with is cracking of the earlier tubular headers. We have always tried to do as much of the fabrication for our kits in-house, however the tubular headers take so much time to fabricate that we have other people fabricate them for us. There have been multiple failures with the first batch of tubular headers. The failures are caused by incomplete weld penetration. Over time some of the cars have had multiple cracks develop at various locations. We tried repairing the first few manifolds, however the time needed to strip the coating, blast the inside and outside clean, grind the cracked sections, and re-weld the entire header is too labor intensive. I will say that any of the later kits with non-ceramic coated headers do not need to worry about the issue since they were welded by another shop. Unfortunately we do not have the resources to replace all of the headers, so we came up with another plan.

We have used cast headers from SPA turbo on numerous E36’s over the years. With multiple tubular header failures, I decided to work with SPA turbo to duplicate our tubular headers into an identical cast manifold. After shipping them our tubular manifold, we soon had a sample that I ended up installing on my own car. The flow path and flange location is identical, however we were able to make more clearance for the rear cam sensor and A/C line. We also increased the inside diameter of the runners to account for some flow disturbances caused by the bolt hole recesses. I have the second revision on my car now, and I can say that the manifold performs as good or better than the previous tubular manifolds. We should be receiving our first batch of manifolds any day now, and the current round of kits are now shipping with them.

To anyone with a previous tubular manifold that has developed a crack: We will be selling the cast headers at a discount to help offset replacement cost. We apologize for the inconvenience, however it is not possible for us to cover the replacement expenses. If you have had the kit less than one year then the replacement header will be covered under warranty. Please email me at and we can go over the details.

THE GOOD(again):

We raised the Stage 1 kit price! How is that good? We actually lowered the kit price to account for the cost difference of the cast header. We are now including an eBoost 2 EBC and AEM wideband, and gauge pod($850 in components) since we use them in every kit besides the first few cars that we did.

That’s all for now. 2015 should be a good year for turbo E46’s!

-Mike and the Maximum PSI crew