FI vs stroker

[ACVC325ix]

So I've been going thru the IX threads for a while now and I was hoping to start a thread to get a definitive answer as to which is the overall better route to go for more power in our IX's: Forced induction or 2.7/2.8 stroker?

I've been turned off of engine swaps due to the extensive fabrication needs the IX's have over its other E30 brethren....I read thru the thread by 6A LDY and it still seems that there are additional fab requirements for the bottom end due to different positions unique to the IX.

So if I want to be in the mid 200's BHP, is turbo'ing the M20B25 stock engine truely the best way to go for the $$$$?

Thanks in advance yall!
:p:p:p:p

[stonea]

FI is basically always going to be the best bang for your buck. However I think FI to just get into the mid 200's is a waste. I'd do a high compression 2.8 with supporting mods and settle for what you get. I'm guessing around 220 hp, but I'm not a expert.

[Nisse Järnet]

Stroker AND FI :D

[berlow94]

The reason that i have just as much fun in my mostly bone stock IX as my fully gutted track car is because of driveability.

I have never experienced a turbocharged engine that had the same torque/power curve as a properly built N/A motor.

At the end of the day, it comes down to your specific goals. Are you looking for more power everywhere under the curve? Or is the bottom end fine for you and you just want to do 170mph on the highway?

My vote goes for stroker and keeping the motor N/A.

[The Dark Side of Will]

Don't waste time with a 2.7/2.8... go to 3.0.

Also, you'll need a good bit of head work and a fairly aggressive cam to hit 250 hp.

[ACVC325ix]

Def looking for power throughout the curve, also want to be able to drive from point A to point B without worrying about breaking something or going through an entire tank of gas lol. The more I learn the more NA seems like its for me...
Still tho, does stroking the M20 in the IX really cost that much more/need a lot of drive train fab?
cheers!

[nando]

Stroking an ix engine is exactly the same as any other M20. You just need to start from an ix block.

[stonea]

Don't waste time with a 2.7/2.8... go to 3.0.

Also, you'll need a good bit of head work and a fairly aggressive cam to hit 250 hp.

If you're buying pistons then yeah just go with a 3.0, but by using early model 325i pistons and shaving the skirts you can get a 10.*:1 compression ratio on 2.7 and 2.8 strokers.

[ACVC325ix]

Awesome, thanks y'all!

[ThatM20Guy]

Would it be possible to shave like 20 thou off the head or block to get it even higher compression? From what i'm looking at all that would be needed to make a 2.8 would be an m52 crank, stock b25 pistons and 130mm rods from an eta?

[Nisse Järnet]

The reason that i have just as much fun in my mostly bone stock IX as my fully gutted track car is because of driveability.

I have never experienced a turbocharged engine that had the same torque/power curve as a properly built N/A motor.

At the end of the day, it comes down to your specific goals. Are you looking for more power everywhere under the curve? Or is the bottom end fine for you and you just want to do 170mph on the highway?

My vote goes for stroker and keeping the motor N/A.

Well, if you take that properly built NA motor and slap a good sized turbo on it, it will just be even better :)

[berlow94]

Well, if you take that properly built NA motor and slap a good sized turbo on it, it will just be even better :)

I disagree with this.
A properly built high output NA motor will use completely different parts than a properly built high output boosted motor.



Sent from my iPhone using Tapatalk

[The Dark Side of Will]

What beyond compressio ratio and cam specs would be different?

[downforce22]

if you are paying for custom pistons, why not go as big as possible? The m20 with 135 mm rods and 89.6 crank has the same dimensions as the s52b32(us) so with quality components, no reason not to rev it out to 6000 rpm.

Turbos are fun and addictive, so are strokers. I like the screaming high rpm power delivery of the s38 but with aggressive cams it doesn't have that power on the bottom end so it isn't much fun to drive when you can't open it up without significantly exceeding the speedlimit. You can atleast size the turbo and plan the engine well enough that when you accelerate up to speed you get that boost kick and turbo noises without having to drive ridiculously fast.

[Wolfman]

I disagree with this.
A properly built high output NA motor will use completely different parts than a properly built high output boosted motor.



Sent from my iPhone using Tapatalk

I'd call an S54 a properly built high output NA motor and look what they're capable of boosted- even with all stock internals!!!