More area under the curve. Turbo conent.

Its a B16 and I will be running pump gas. 93 is available here but 91 is more common so thats what ill tune for when this happens (it'll be a bit.)

Its not really low end torques im looking for ( i dont consider it low anyway, and if i get more on the low end, I'm totally ok with that). What I want is a broader/stronger mid-range.

As for tires I will run street tires for the most part but I like to buy used 225/50/15 r compounds (usually RA-1s) when I can.

The car is used mostly for autocross, the small "time attack" events I put together locally here, and some back roads cruising to keep me sane. A track day reliable set-up would be awesome but that's kind of a pipe dream as I havent done one yet but I would like to.

Another option that just popped into my head is boost-by-gear. That would be nice for keeping wheelspin in check.

Hmm... longer gearing may help. That will be much nicer on the highway.

Oh, another thing. Air conditioning stays. Theres no way im getting rid of it. The car doesnt have power steering but Im thinking about using an MR-S electric power steering pump to put power steering on it. This would be mounted where the battery would normally be and in turn the battery would be moved to the hatch. Using this set-up frees up quite a bit of room for a downpipe.

The reason Im thinking about putting PS on and keeping the AC is my goal here is to make the car easy to drive, fun to drive, and reliable.

While racing, how often are you REALLY going to be under 3000rpms? The double edged sword i've experienced with FWD turbo "grunters" is that the powerband offered by a small turbo isn't really ideal for coming out of corners UNLESS you're set up like Dave and truly can put it down.

You mention backroad cruising and time attack. I'd concentrate on getting a more progressive spool up with a small touch of lag so you run a smaller chance of braking traction on exit. Your standard T3 50trim or maybe slightly smaller in the 44 range or so should give you a nice spool up, have no problems meeting your power goals, and you'd still have a fat 4000rpm or so powerband.

If it was strictly an autox car, then the tiny turbo on a high comp motor is really the recipe to go with. But as a jack of all trades, with street driving thrown in, it's not a recipe that i personally would go with. YMMV.

I have a FWD turbo "grunter." It sucks, bad. Granted, i'm making something like literally twice the torque Dave does, so it's not a straight forward comparison, but well... you know.

As for the A/C, sure, keep it.

The PS, i'm not so sold on. The car didn't have it from factory, correct? Is it really that hard to drive? Any cars i've driven with factory manual racks hardly take any more effort than most power racks i've driven. Unless the move is to facilitate the use of a tighter ratio'd rack?

92CelicaHalfTrac wrote: While racing, how often are you REALLY going to be under 3000rpms? The double edged sword i've experienced with FWD turbo "grunters" is that the powerband offered by a small turbo isn't really ideal for coming out of corners UNLESS you're set up like Dave and truly can put it down. You mention backroad cruising and time attack. I'd concentrate on getting a more progressive spool up with a small touch of lag so you run a smaller chance of braking traction on exit. Your standard T3 50trim or maybe slightly smaller in the 44 range or so should give you a nice spool up, have no problems meeting your power goals, and you'd still have a fat 4000rpm or so powerband. If it was strictly an autox car, then the tiny turbo on a high comp motor is really the recipe to go with. But as a jack of all trades, with street driving thrown in, it's not a recipe that i personally would go with. YMMV. I have a FWD turbo "grunter." It sucks, bad. Granted, i'm making something like literally twice the torque Dave does, so it's not a straight forward comparison, but well... you know. As for the A/C, sure, keep it. The PS, i'm not so sold on. The car didn't have it from factory, correct? Is it really that hard to drive? Any cars i've driven with factory manual racks hardly take any more effort than most power racks i've driven. Unless the move is to facilitate the use of a tighter ratio'd rack?

I like your point. Im not often under 3000 rpms so that is something I should keep in mind. A fat 4000 RPM powerband?... I would like that. I wouldnt concentrate too hard on the backroads driving. I do it but I do NOT push it too hard. It feels wierd driving over 5/10ths on the streets anyway. I just threw that out there because its basically the only time its driven on the street if its not driving too/from events and I only do it when I'm stressed or something is bothering me.

Your correct about it not having PS stock. This of course doesn't make it "hard" to drive. But at times yeah it can be kind of taxing. When I use the RA-1s I fight the steering wheel. I do have a smaller than stock steering wheel so im sure if I bought a larger diameter one it wouldnt be so annoying. As for going to a better rack and pinion ratio that was the plan, more than likely an integra rack ( I believe its 2.9 LTL)

Small turbos run out of breath too so there's that to consider. They lose efficiency at higher rpm.

If you want to help low end, increase the size of your downpipe and exhaust, that will help spool.

VTEC isn't great for boost but it works.

92Celica: Something to remember about that F2T you've got is it is an undersquare engine with all of the torque and lowered redline that classically go with that configuration, as well as a cylinder head that promotes swirl and torque as well. Comparing it to your average four cylinder engines that get boosted like SR20's or B16's, etc, may lead to inaccurate assumptions. If you're going to make power with an F2T it will come with a pile of torque, which is one thing to really like about the thing. I find it odd that it came from the same company that handed out so many magic spinning triangles, like the piston guys wanted to show just how different their engine could be from the rotary developers.

MrJoshua wrote: Miataturbo.net has lots of 1.6 turbocharged cars. If you like to stay out of fights, read lots and lots before you post anything.

Don't even bother going there. It's a bag of shiny happy people. You'll get the info you need here or at miata.net. Trust me. Avoid, avoid, avoid.

Back on topic...

I've got a GT 2554 on my 1.6L Miata. All in with 10lbs of boost at 3k. The power curve is manageable. I haven't dyno'ed yet so I can't speak to the power gain but it is significant.

I like the power delivery and I'm using a regular vacuum modulated waste gate. I have a 2.5 mandrel bent exhaust with two Moroso spiral flow mufflers. The power delivery is linear but most definitely builds with the rpms at a reasonable, and controllable, rate.

pres589 wrote: 92Celica: Something to remember about that F2T you've got is it is an undersquare engine with all of the torque and lowered redline that classically go with that configuration, as well as a cylinder head that promotes swirl and torque as well. Comparing it to your average four cylinder engines that get boosted like SR20's or B16's, etc, may lead to inaccurate assumptions. If you're going to make power with an F2T it will come with a pile of torque, which is one thing to really like about the thing. I find it odd that it came from the same company that handed out so many magic spinning triangles, like the piston guys wanted to show just how different their engine could be from the rotary developers.

Yep, i agree with all things you said.

I think my example came late, though, as i was aiming to try to show it as why we needed to know exactly which motor he was talking about, and as an example of what happens with too small a turbo, though probably not to the degree of the F2T.

Strangely, a monster HX35/40 hybrid has a much more manageable power curve/delivery on this motor than what i've got. I usually prefer to err on the side of the turbo being bigger than what i would truly need. To a certain degree, lag caused by a "too large" turbo can be remedied. It's much harder to get a turbo that's a little too small to act in a civilized manner. I have the gain on my boost controller turned to "zero" and my spool/delivery still has all the refinement of getting rear-ended by a cement truck. 0psi to 20psi in literally less than a second.

I DO love the torque the thing makes, because more is better and all that, but it's the way it does it that i'm less than enamoured with. It's the most ill-suited 4 cylinder for FWD that i've ever run across.

Perhaps a swap into an FC RX-7 for instant drifto excitement is in order?

Not cheap, but variable turbines will make it flat like a pancake.

Holset HE351VEs can be had for cheap, but i think the massive weight of one may be a turn-off.

curtis73 wrote: Not cheap, but variable turbines will make it flat like a pancake.

Tell me more. Who makes them/how do they work?

EDIT: just read up on it. It sounds VERY expensive.

Garrett makes VNT's that are available on VW TDIs as well as some others. Maybe look on Ebay in europe or canada for a used VNT 20 or 25?

They aren't truly worth it in your application. They're a nightmare to get working properly in an aftermarket situation.

There is a way to control it with megasquirt, but from what i've seen, it isn't for the faint of heart.

92CelicaHalfTrac wrote: They aren't truly worth it in your application. They're a nightmare to get working properly in an aftermarket situation. There is a way to control it with megasquirt, but from what i've seen, it isn't for the faint of heart.

lol Sounds like I better not go that direction. I need to start looking for dyno graphs.

Then there's the Rotrex supercharger.