Time Attack/Street Rotrex NA8 Numbers, Questions, & Insight...
 

Within the last few weeks I finally got around to getting my car dyno tuned after installing the Rotrex and some other supporting mods.

Wondering what some of you more experienced members think about the numbers and also why insight you might have as it comes to tracking a Rotrex Miata.

Car made 240WHP/189WTQ on a Dynocom.

Here's what's done to it pertaining to the power.

•235K STOCK BP-ZE Motor
•ExIntake Mod/KAInjection Adjustable Cam Gear
•Racing Beat Header(Ceramic Coated/Heat Wrapped)
•Unknown Catalytic Converter(looks to be higher flowing)
•Flyin' Miata 2.5in Catback Exhaust
•Rotrex C30-74(80mm Pulley)
•RX8 Yellow Top Injectors(425CC)
•DW200 Fuel Pump
•MS2PNP
•E85 Tune
•7500RPM Redline

Car is being prepped for Time Attack and HPDE and is still street driven to and from events as well as around town, to work, and to the mountains when I'm up to it.

Turn that redline down to like 7200 and shift at 7000 unless you've already got another engine on standby. Other than that, should be a fun car as long as the cooling system and other reliability concerns are taken care of.

Any slipping issue with that adjustable cam gear? Design looks nice for our motor with the extra hole for the exhintake mod, but people here have been telling that adjsutable cam gears are not the most reliable thing in the world...

The redline is set that high to give me extra gearing on track(MSM 6SPD, 4.10 FD) and it's tuned as such up there(timing retard, fuel dump, etc). I shift at 7K though.

Car has Flyin' Miata Crossflow, Fan shrouds(w Spal fans), and coolant reroute. It's also got a custom vmount intercooler setup and custom ducting to add efficiency to all the cooling items. Overheating shouldn't be an issue, especially since I'm on E85(it burns cooler than gasoline).

I haven't had any issues with the cam gear slipping but that is something I'll look into. I wasn't aware people were having issues with that. Thanks for the insight.

240whp on e85 on only 420cc injectors...:eek3:
what fuel pressure do you run?

ID1000s are one of the mods coming soon. I know my injectors are pretty much max duty cycle. I have stock fuel rail and no fuel pressure regulator so I'm not sure of the pressures. My tuner was monitoring them during dyno tuning though so I'm sure they aren't "unsafe."

Boosting a stock 235k longblock is very bad idea. I wouldn't bother doing leakdown or compression test, just rebuild it. If you have the budget, add forged 10.0:1 pistons, rods and heavy duty valve springs. Not a bad idea to add either billet oil pump gears or at the very least a better crank damper and shim the pump for a bit more pressure.

Speaking of what you haven't done: you gonna unblock my buddy and finish paying him for that rotrex / header?