Dyno Tuning Rotary Cars in Chesterfield, Michigan at Alex's Automotive

Published 2024-02-21

Pretty incredible group of folks yesterday. #mazdarx7 #rx7 #rotary

@yaboiiiiiimike started us off at 8am and we landed at a very comfortable, reliable, responsive 425whp with a meaty powerband. We didn't feel the need to push it on pump gas as later on after the alignment and new tires we planned to switch to e85 for his flex fuel tune.

@noxender followed up with the challenging car of the day. Legend Motorsports had an EMF gauge on hand and we all jumped in to diagnose what could possibly be causing such a ruckus. Aluminum foil hats and everything, we had an amazing car one moment and an absolute disaster the next. You'll hear it in the video of coming on boost and the motor practically stalling at 2700 RPM, 7psi until it finally got out of its own way. Extremely odd behavior, especially for a BorgWarner EFR9180.

We later tested this car throughout the evening after going through basics and some exotic testing. Landed with oil pressure never exceeding 80psi, which doesn't match the power goal, ECU likely a culprit, which may be the first I've seen, and some harness/wiring small fixes. I know this will turn into a beautiful success story.

@speednessrx7 hopped on with a track prepped, well engineered masterpiece, and our first rip up to only 6k exceeded our total goals for this unknown motor. We finished up at a solid 422whp/368wtq with broad powerband from the EFR8374. This car would have made 480-490whp if we wanted, but it was detuned heavily for track usage and purely on wastegate pressure at this power level. We decided to inspect plugs like always and another new lesson from Legend Motorsports appeared; rear trailing plug smelled distinctly like dowel pin stretch, and sure enough, checking over logs on EGTs, our hotter rotor swapped to running cooler once in boost. Internal Water Injection! A set of ARP Studs will fix this block and have Michael reliable for many track days to come.

@midwestwankel shows up next and we all hover around to see what a 10k+ RPM NA setup can do... I'll leave this for the videos, but we picked up ~30whp from our previous best. This is what happens when you throw the purse at it, I suppose.

Then it was time for e85...