After installing my new fuel system and turning up the boost on my MMP Stage 3 turbos, I started to notice some really bad heat soak in my logs. Guessing that the car is around 600-650whp at 28PSI, I could see that my standard VRSF 7″ Street intercooler was no longer keeping up. It did a great job on my stock turbos, but I needed something a little bigger.
After doing some research, I found the VRSF 7.5″ Race intercooler. Judging by its size and efficiency ratings, it seemed like the perfect intercooler for my power goal of 700whp. I ordered it right away to help cool things down a bit. Four days later it showed up, very nicely packaged.
After installing MMP Stage 3 turbos on my BMW 135i, I needed an upgraded fuel system to get the most power out of the car. I was filling up with an E40 mix of 93 and E85 , but my HPFP couldn’t keep up and my old stage 1 inline LPFP was inadequate. I needed something that could handle straight E85 fuel and not run out of pressure at 700+whp.
The products arrived quickly and were packaged nicely. I’ve always been satisfied with the quality from Precision Raceworks for the price. Upgraded fuel feed line not pictured.
The first step was to install the upgraded Stage 3+ bucket that had two Walbro 450s stuffed inside. Robert was nice enough to assemble the fuel pumps in a core bucket for me to swap out. Usually you have to modify your stock bucket while mounting and wiring up the pump yourself. I jumped in the back seat and got to work.
On a constant quest for more power, I found myself looking to upgrade from my stock turbos. There are a few different options available, and even some single turbo conversion kits. After doing some research, I was set on a pair of MMP Stage 3 turbos. They offer 700whp capability with OEM fitment and come at a great price. After hearing praises about Mauricio’s customer service at MMP, I decided it was a no-brainer and pulled the trigger!
I opted for fully-optioned MMP Stage 3 turbos which included a 2 year turbo warranty with the bearing treatment. These turbos require larger inlets and outlets, so I opted for MMP’s silicone outlets and aluminum relocation inlets since I already relocated things for aftermarket inlets on my stock turbos. I also ordered the turbo install kit because I wanted fresh o-rings, gaskets, etc.
After reading some DIY N54 turbo install guides, I decided to tackle the job in my garage on jack stands. This would be one of the most involved projects I’ve ever attempted on my own, but I knew it was possible.
If you’ve been following my website, you probably read my detailed post about installing a 335is/550i clutch after my OEM clutch wore out. However, with MMP Stage 3 turbos on the way, I knew the 335is clutch wouldn’t hold as I turned up the boost. With a goal of 700whp, I decided to replace it with a SPEC Stage 3+ clutch and retain my MFactory single mass flywheel.
Since I just installed an MFactory SMFW about 20k miles ago, I decided to reuse it because I knew it was in good condition. All I had to do was purchase a SPEC Stage 3+ clutch with OEM or MFactory flywheel configuration so it would mate up properly. If I didn’t already have the MFactory flywheel, I probably would’ve bought a SPEC flywheel to go with the clutch. However, I’d rather save some money when possible!
Since the transmission was going to be removed, I wanted to refresh a few things at the same time. I noticed my shifter developed some side-to-side slop so I decided to upgrade the bushings. The car has almost 120k miles and still has the OEM transmission mounts, so I knew those could be replaced. I’ve also never servied the rear differential and noticed it was seeping a tiny bit of fluid. Might as well replace the rear pinion seal and flush/refill the fluid!