Mark or anyone else,

Have you run a .63 turbine on a T3? This would be on a 1.8. I'm wondering what the spool vs. top end differences are between the .48 and .63. I've got a T-bird .60/.63 coming and am getting it rebuilt with genuine Garrett stuff and balance. I can get a vanilla rebuild for $130 or get the rebuild, trade the compressor housing for a 300zx housing (gets rid of the bold on flanges for the intlet side and intake) and trade the old .63 AR hot side for a .48 hotside for $200.

Opinions?

Thanks,

Frank

 

I'd keep the 60/63. I'm running that exact turbo on a 1.6L civic and it is great across the board. Was told many times it would spool slower... it never did. Spools great and holds without issue to redline.

 

You will definatley have a little more top end oomph. Give it a shot and see what you think. A .48 housing is under $100 if you don't like it.

 

It will spool a little more slowly, but will you notice it... Not if you drive your miata normally. If you plan on pulling from 2000 RPM, yes, you'll notice it.

Above 4500 RPM, you'll notice that you make more power with less boost. It's also dependent on your local altitude, at 5500 ASL, small changes like this make a bigger difference when the air is already thin... At sea level, it's less of an issue.

Remember the A/R is the fine tuning of the wheel. It's not going to make or break the installation. While it's a little large for the Miata, I don't think that you'll find it objectionable, and if you do, other housings are available.

Mark

 

what would be the advantage/characteristics of using a .60/.48 vs. a .42/.48?

 

Even a .48 stage one is overly large for what a T3 60 can flow. All it will get you is a pile of lag.

The stage 1 is supposedly good to about 300whp while the stage 3 is good for 350+.

The .63 is good for 400+ depending on trim. I would personally avoid this size for a street driven miata, even a 1.8.

But keeping the .63 is free, and if you dont like it you can always buy a smaller one for cheap. T3 .48 manifolds are a dime a dozen in junkyards.

 

The .48 with the standard turbine wheel is an excellent match for the T3 60 trim compressor. Thats what makes it the best way to go for a Miata that wants between 200 and 300 whp.

 

hey...riddle me this!

would a larger A/R compressor housing be useful in low boost whereas a larger A/R benefitical in high boost? The converse of a turbine housing A/R..correct?

If so would someone such as myself benefit from a .60 A/R compressor housing when only boosting 10-15psi?

 

The best thing for compressors is to learn to read maps, and/or build a spreadsheet to do the math for you... Going of a suspect sheet I made up, the 60 would be pretty nice, maybe a bit big. Getting the turbine matched to the exhaust flow might be tricky, I think a .63 might be largish.

*disclaimer* I learned just enough about Garretts to become a Mitsu Man.

In general, B, the 42/48 (OEM on lots of Volvos, where I learned the little I know of turbos) is quick spooling but runs out of steam early. The 60/48 would make a good street turbo, but the 48 turbine becomes a bottleneck at high RPM. 'course, this is on a 2.1 or 2.3L 8V at 6000RPM. My math makes a 1.8L at 7000 roughly the same... my concern would be getting enough flow to spool the turbo at useful RPM.

And that, boys and girls, is why I went Mitsu - they're not as impressive to behold, but really efficient and lightning quick spool. I was making 7PSI at 2000RPM and 15 by 2400. The 42/48 spooled slower and didn't run well above about 12.

*see disclaimer above, and remember that I'm a n00b here.

 

I like bigger turbos. Lag is overrated. I've got a Mitsu turbo on my Forester XT. Actually it's got a 49 lb Garrett compressor wheel though.

If the 48 is a bottleneck on the T3 60 why does everyone recommend running the 48 on a T04E?

Frank

 

I understand compressor trim.

But I'm only asking about the diffence in A/Rs on the compressor housing using the same compressor/turbine wheel.

I have a S60 wheel and a .42 A/R housing with a Stage 1 turbine and .48 A/R housing.

What would the differnce be at 10psi compared to a S60 wheel and a .60 A/R housing with a Stage 1 turbine and .48 A/R housing? I assume the opposite of a turbine, so better flow in lower boost.

 

now dont mention compressor trim or turbine housing sizes in the next post.

 

People are running T3/04E with a .48AR Turbine? Seems like a helluva mismatch to me, but it might make sense on high RPM small displacement engines... see my disclaimers and pitiful postcount I like both, really... my wife's wagon's turbo is pretty transparent, and not a lot of fun. On my MSnS project, I frequently (too frequently, according to my wife) swapped cams to move the powerband from 2000-5000 or 3500-7000. Both have their merits. The higher RPM setup made more power, and was faster, but the torquier fast spool was crazy fun around town... booost/psh/shift/boooost/psh/shift/boooooooost/psh/shift by 30 miles per hour. Man that was FUN.

I PISSED SCOTT OFF AND MENTIONED COMPRESSOR TRIMS SO I LOST HALF MY POST
hahaha, I was wondering what happened. Sorry, got carried away.
http://www.turbomustangs.com/turbotech/main.htm#ar

 

Compressor housing A/R: The discharge cross-sectional area divided by the radius from the turbo centerline to the centroid of that area

Compressor Trim: Inducer^2 / Exducer^2 x 100

 

I'm going to keep my eye on you!




So back to the question at hand:

I have a S60 wheel and a .42 A/R housing with a Stage 1 turbine and .48 A/R housing.

What would the differnce be at 10psi compared to a S60 wheel and a .60 A/R housing with a Stage 1 turbine and .48 A/R housing? I assume the opposite of a turbine, so better flow in lower boost.

 

So is that an explanation or a further obfuscation? Nissan used the .42 housing IIRC on the 3.0V6. Ford used the .60 on the 2.3LI4.

Now that I think about it, it reminds me of intake runners... somehow. It wouldn't surprise me if the difference is small. It also wouldn't surprise me if boost is irrelevant - that's what led me into looking at the maps.

 

yes I assume the difference is small if really any. But I was just thinking about it.

 

Because the .48 Straight T3 has a Stage1 turbine wheel. The T04E's that are worth a **** have a stage 3 wheel thats good for about 400whp in the .48a/r.

 

damnit Andy, why'd you answer his question and not mine.

 

Well lets think about it like this...when you move to a larger turbine a/r with the same wheel you buy some extra lag but also increase flow and lose backpressure. Now, I know the same doesnt apply to the compressor since it works a bit differently...but I am going to guess that with the .60a/r compressor housing you might give 100rpm in lag but will be able to utilize all of the flow from the S60 wheel. Since the S60 wheel was originally designed to work with the .60/ar housing I bet it would be a little happier in that housing. Just for refrence when I was running a 60/48 S60 T3 I had 10psi @ 3500rpm and it would just pull all the way to 7200 without a sweat. I bet you would see about 5whp at 10psi and under and maybe 10-15whp past 15psi or so...but again thats speculation.