On a stock vvt head, forged 9.5/1 pistons, 2.5” exhaust, smallest pulley for 120000rpm @ 7200rpm, we are seeing 270hp (crank, because that’s how we measure it in Europe) power delivery is so smooth, I would say. 74 is a waste of time. Looking for options to hybrid it to a 94.

BTW, from the original Kraftwerks kit, nothing is left from the kit, at this power level.

 

Use stock cams. Consider the TSE Turbo kit if you want torque. Personally I'm going with Rotrex for the ironic lack of torque, in hopes of keeping a motor alive for more than two seasons per rebuild.

 

>wants low end torque
>considering hands down least low end torque providing f/I application

lol

 

I don't see the problem. he can spool his rotrex with compressed air.

 

you know you can do this crazy thing called: tuning.

 

Guys are keeping this entertaining

OP, what about your son’s set-up that you don’t like?

Exactly what problem are you trying to solve?

 

I enjoy rotrex for it's lack of torque as well. Notice how I said "as much torque as a rotrex can have". I'm not looking for the 300wtq a efr would easily give me. I find my rotrex infinitely easier to drive on track than my FM2 car making a similar amount of power. Every time I push the pedal, I immediately get the same response. Maybe it's because I'm a novice driver, but I just prefer that. 250whp is 250whp however you get there.

 

A motor making 220wtq will always have a longer lifespan than the same motor making 300wtq. Tuning fuckups can melt a rotrex car the same way they would a turbo car.

 

This may be a silly question but why don't people ever run the C38 size units on Miatas?

 

Heads don't flow, so no need. Plus weak transmissions are always an issue.

 

Back to the injector question. I have the options of 750cc or 1000cc at the same price. Does it make sense to just run the 1000's and not look back? I'm not sure, but I've been told that idle can sometimes be a problem with the bigger injectors. Seems to me that with the ms2 less on time should be fine.

 

again: tuning

 

If they are ev14 injectors the 1000cc will idle fine

 

Never followed though with a build thread, in fact I think this is my first post
essentially I have a nice churbo build. Lots of influence from previous builds i.e. 18psi style intercooler routing.

 

What are those graphs showing? Is that controlling boost so it builds gradually to redline? Why would that be preferable over a centrifugal supercharger? Wouldn't the torque still be as low?

 

I'm just saying, if youre worried about tq, you can tune torque.

 

Brain,

Your plots show that the tune increased boost on a turbo'd car, which increased hp and torque. On a Rotrex equipped car, would a superior tune increase BOOST over an average tune?

Thanks,

 

a turbo doesnt have to run full boost at all times. If you have an EBC, you can tune the boost output. If you're worried about too much tq, dont let the turbo produce too much torque.

 

No. The boost that a Rotrex unit produces is a direct relation to the engine speed (rpm) and pulley size (ratio). No tune will change the amount of boost you make on a Rotrex.

Can tuning change the laws of thermodynamics to fix the inherent massive heat issues that accompanies turbochargers? No doubt, I think turbocharging is better for the OP and anyone would plans to do more street stuff than track stuff. But between turbos falling off (fixed by inconel studs and better hardware), cracked manifolds, High CLT's and oil pressure, high IAT's, wastegate issues etc. you have to at least admit that the Rotrex systems have some appeal to the track only guys. People that want to just stick it on, tune it once, and never have to worry about anything at the track except for suspension/tire setup and driver mod. I was able to hop in a Rotrex car and go extremely fast within a lap, and I'm not the only one that has that same story. Rotrex cars are just easy to drive fast on track without issues.