Thanks, that was quite the info I was hoping for! It is really nice to hear from one that has 1st hand experience. I have ridden alongside a (badly executed) turbo and driven a MINI M45 car; I preferred the latter to be honest. Not in terms of absolute grunt, but in terms of delivery. Again, I do not want/need more than 170 hp, but I would love to have the most instant delivery I can get. If I got to get a turbo, I would shoot for a 2554 or similar.

 

M45 kit would work for your goals. Simple, reliable, cheap. Don't build one, it's a waste of time when there are well designed used kits CHEAP. Everything turbofan said is spot on.

I've driven ~350whp turbo and ~350whp supercharged miata. Turbo was easier to build by far, and faster on the highway and more reliable. SC is better to daily, and faster to 60mph and wayyy more fun in 1st/2nd and just pinning the gas.

 

in what world is a m45 producing less heat than a turbo?

or do you just mean underhood temps? cause what your engine is ingesting with a supercharger is basically lava. even with an intercooler, a roots charger is heating up the charge like crazy, they call them heatons for a reason.

 

Yeah, had in mind engine bay temps instead of IAT.

 

lol.

 

and that matters because?

 

you should just install a VVT motor and call it a day.

 

Sir,
In my view, you have made the decision exactly backwards.

Heat under the hood from glowing red hot turbo pieces is zip for a problem.

Heat in the air charge due to the thermal efficiency of the air mover is the MOST important factor. The difference between the M45 Roots blower and a typical turbo is well described by this: The thermal eff lower limit of a turbo should be 65%, whereas the peak efficiency of the M45 is 55%.

Heat in the air charge entering the combustion chamber is the cause of knock and the reduction of the air density. Both of those are the limiters of power.

And, building SC components is much more difficult than a proper turbo.

You are on the classic path of putting a lot of work into a system doomed to poor performance because of the wrong choice of air mover, which will result in your disappointing (and wrong) announcement that forced induction is not worth the effort.

Please, just polish up the M45 and sit it on your coffee table where it belongs.

corky

 

I shall return a cat to you, sir.

 

New sig

 

Thanks for your input! Might not be much of an issue, still worried about heat soaking etc. during DD.... We shall see.

 

Not for nothing but Mazda made a DD that had a turbo. And with proper auxiliary components, they can make upwards of 200whp. I think with just a proper tune they can make 170whp.

I'm not telling you to build/buy a MSM or stick a MSM engine in your car. I am telling you that you are fixated on creating a power solution that has many pitfalls and that better options are out there without the hassles everyone is warning you about. Not only that, there are options already made that you don't have to even invent anything for.

So build it if you like building. There is no doubt a sense of pride and accomplishment to that. Just realize pride is a deadly sin.