You should be looking at 3". Back when I had the Corrado, the 3" exhaust was the last thing I added. It went from like 380whp to 480whp just from the exhaust, removing the cat, and added spark angle.

I suspect the exhaust is your bottle-neck.

I cant read and so i missed the crushed exhaus and resonator

Id say that could accout for 20-30hp. Rest could be timingz.

Btw i wouldnt jack timing without a way to check for knock. This is not the stone age.

Yeah 20-30hp would be 175-185, I would NOT be disappointed with that, and could probably find the other 10-20hp to make me really happy with a little fiddling with the MBC and timing.

Threads like these make me afraid to get on a dyno, but also more determined to find out what I'm making. What do you guys think about using the dyno software that reads a log to generate a dyno chart? Anyone compare one of those outputs to a real dyno?

just strap on a dynojet for realsies.

Cat looks ok:

https://www.miataturbo.net/attachmen...ine=1342713376

Dunno if you can tell, but there's no melted sections and I can see through it easily. Damn inner diameter is only 2.3". I don't care if the O.D. is 2.5", that's a ------- 2.25" cat if you ask me.

Gotta fix this damn thingy too. Those two center bolts on the timing plate broke off a while ago, it's never scraped until I started it up. Should be an easy fix. Might gut the plate to the bare timing marks. Or just bash it back with a hammer.

my 300? cell metal core:

https://www.miataturbo.net/attachmen...ine=1342713529

http://www.boostedmiata.com/gallery2...huza_cat_2.jpg


there's maybe like 3-4" at most of length of catalyst.

Curly, I have a brand new 3" metal core stainless cat with a little straight pipe on it sitting in my garage. Yours for $120 shipped.



The largest and shortest pipe is always best. It will always make a big differene in both spool and overall power.

Why don't you just use a test pipe for track days/ everything else, and just bolt a cat on to pass a sniffer???

about 3 hours to the closest one .. =(

I will do that though, eventually.

^^^ Put that thing on the DynoDynamics in town when you come up for the hillclimb.

Curly, any chance you'd punch your log into VirtualDyno for a comparison?

Show me some pics! I'd probably have you send it to Artech for modification. PM some pics!

This has been suggested, and it's certainly a possibility. I already jack the car up to bolt my seat in for tracks farther away, undoing two V-band clamps and sliding in a test pipe wouldn't be much more work. The ~$200 cat and 3 v-band clamps wouldn't sit well for only using it once every couple years.

However, since I drive this on the street, I should think of it more like a straight piece of $20 pipe with v-bands that I only use for track days, as the cat would help muffle things.

Actually, ignore the v-bands, cause I'd have to send my dp back to him for modification, and I'm not doing that.

I pm'd artech. I'm pretty sure he hates me.

Sure, lemme d/l the program. Is it free?

Yep, well donation based. Close :D

http://www.bradbarnhill.com/projects/VirtualDyno/

I like this idea. Where is it located, and who would I contact about it? If it's reasonably priced I may do exactly that. We just put a gt2560 on my brothers s14 and he wants to dyno it as well.

PM'd to end the threadjack :)

Looks exactly like this, but without the flanges.

NA, miata, mx5, racing, cat pipe, off road, stainless steel

Probably costs you around 10 HP at 200hp level.

Cat converters are for homosexuals and women. I didn't compare to a dyno, but I went from 11.5-11.8AFR on ramp runs when I removed the cat converter from my car. That's more air, son.

There's a good chance that the muffler shop who made the crush bent exhaust also used a chambered, not straight through, muffler. Add that to the list of bottlenecks.

You have pm.

I think I'll take it, dunno if it's being sent to Artech or not yet.

Yeah, I can't get it to work. Won't accept my MLV logs.

Lies! I has no PM.

I bought the muffler myself, it's a magnaflow straight through design, specifically for turbo cars.