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-   -   My turbo specs - opinions? (https://www.miataturbo.net/diy-turbo-discussion-14/my-turbo-specs-opinions-32424/)

Project84 03-07-2009 05:33 PM

My turbo specs - opinions?
 
I bought the car w/ the turbo and hack-job setup installed, none of it running. Well, now we're idling and trying to make plans to finish the project.

I wrote down the spes on the turbo today to see what you all thought of it.

T3/T4
TO4E
A/R .63

Sitting on an OBX stainless manifold. (I've heard these are junk)

There is currently a v-band clamp on the exhaust side and it's 2 1/2" mandrel bent DP to a full 2 1/2" exhaust, no cat.

Intercooler piping is 2".

Should I expect lag?

At what RPM will I make 10psi if I'm correct in thinking I have the 4.10 (open) diff. My car is the base model, not sure if that matters or not w/ the transmission gearing.

Thanks fellas.

Mach929 03-07-2009 05:42 PM

it's going to be laggy i'd guess 10psi between 4500-5000

Project84 03-07-2009 05:45 PM

Oh, really man? That sucks!

What **inexpensive** ways can I improve on that? Would a smaller turbo be a better idea? Maybe find someone wanting to upgrade and trade them?

Mach929 03-07-2009 06:08 PM

what is your ultimate power goal?

Project84 03-07-2009 06:13 PM

I'm still trying to figure that out. I figure for now, the goal is to get the most I can out of this setup because I bought it as a whole, and I'm wanting to keep expenses down as much as possible since I'm not even sure I'll be keeping the car or buying a newer Miata to do my own start/finish on. I bought this for what I thought was a good price, and I really just want to get my feet wet w/ turbo cars and modifying in general.

So that all said, I'd like to dyno at 200whp. That would make me grin. But more than that, I'd like to hit 10psi (where I plan to run it on the street) at like 3,000 RPM or less if possible.

Mach929 03-07-2009 06:20 PM

if you want 200whp and 10psi by 3K it's recommend a smaller turbo. since you're already a t3 platform i'd recommend a t3 super 60, search it's well documented on the this and run by braineack. however that turbo even on a 1.8 might fall a bit short on your desired spool on certain setups. 3" exhaust and headwork are your friends.

you could also go for a 50 trim t3 but it won't be able to make much more than 200whp when your goals climb

the turbo you have now is a good turbo for a 300whp+ application

Project84 03-07-2009 06:30 PM


Originally Posted by Mach929 (Post 378826)
if you want 200whp and 10psi by 3K it's recommend a smaller turbo. since you're already a t3 platform i'd recommend a t3 super 60, search it's well documented on the this and run by braineack. however that turbo even on a 1.8 might fall a bit short on your desired spool on certain setups. 3" exhaust and headwork are your friends.

you could also go for a 50 trim t3 but it won't be able to make much more than 200whp when your goals climb

the turbo you have now is a good turbo for a 300whp+ application

You're very kind for taking time to help me out, thanks!

300+hp with this turbo? That's impressive.

So, I'm re-doing my DP currently anyway because the bungs for the o2 and WB were installed too close to the turbo, should I just cut the entire DP off and scrap it, save the 2.5" v-band, and buy a 2.5"x3" exhaust adapter and finish the car w/ 3"? I'm only planning to run the exhaust as far as necessary to install a glasspack and two side exit tips on the passenger side, probably exiting in front of the passenger rear wheel.

When you say headwork, I'm assuming you mean port the exhaust side as much as possible, correct?

I just want to write a brief note on why I'm such a newb. lol

I've been a Camaro guy for 7 years, I slapped headers on two different LT1's and made 300+whp and was happy as could be. This is a whole new game for me. Seems to be pretty technical.

Mach929 03-07-2009 06:37 PM

it's completely up to you and your eventual power goals. a bigger exhaust is always better with a turbo but a 2.5" could easily satisfy your needs.

i'm no expert on headwork as i'm never done any but done properly can yield impressive results on spool

Rafa 03-07-2009 07:41 PM

John, I have a T3/T4 on a 96 also. I have a 2.5" exhaust and made 212whp at 9psi. I used to see full boost around 4,200 rpm.

I think you're going to need bigger injectors soon. If you're mechanically inclined I would consider doing something to the head. That should help you see boost earlier in the rpm band. Other options, such as a 3" exhaust would be too expensive.

Project84 03-08-2009 11:24 AM

212 at 9psi? Did you have any head work done or were you all stock? That's a pretty good number.

I was under the impression that with the 190HP fuel pump and the EMB I could run the 305cc injectors and be pretty safe? What injectors would you recommend? I went looking for the 305's because I wanted a PNP injector rather than wiring up resistors, but I can solder, so I guess if it's widely agreed I should upgrade, I'll do it now rather than later. They aren't even installed yet.

Project84 03-08-2009 07:57 PM

Guys, more background.

The car will probably just be a toy for street driving. I have the Camaro for Auto-X, but might take the Miata a time or two. So more than likely, I'll just use the car to surprise ricers, challenge friends, carve some country roads, etc.

Would any of you suggest I take an offer from someone and trade to a 25k mile used gt2560r w/ BEGi manifold and downpipe for my current setup?

Benefits vs. non-benefits?

I understand it'll be quicker spool, but does it fall flat up top? Should I even worry about that since I'll rarely see redline? What is the most boost/HP I could attain w/ a 2560r if I ever wanted to go faster (which seems to happen to all junkies)??

Rafa 03-08-2009 10:13 PM


Originally Posted by Project84 (Post 379037)
212 at 9psi? Did you have any head work done or were you all stock? That's a pretty good number.

I was under the impression that with the 190HP fuel pump and the EMB I could run the 305cc injectors and be pretty safe? What injectors would you recommend? I went looking for the 305's because I wanted a PNP injector rather than wiring up resistors, but I can solder, so I guess if it's widely agreed I should upgrade, I'll do it now rather than later. They aren't even installed yet.

A little porting but nothing extraordinary. I think in my case, the ECU I'm using really made a difference. The first time we took the car to the dyno after extensive road tuning, my tuner could only get 4 additional whp from my setup.

You can check the dyno sheet in that section. I posted it a while back.

About the injectors: my suggestion would be to look for 550cc. We all start with a specific whp goal in mind and end up braking it. Ask me how I know! :giggle:

Rafa 03-08-2009 10:17 PM


Originally Posted by Project84 (Post 379170)
Guys, more background.

The car will probably just be a toy for street driving. I have the Camaro for Auto-X, but might take the Miata a time or two. So more than likely, I'll just use the car to surprise ricers, challenge friends, carve some country roads, etc.

Would any of you suggest I take an offer from someone and trade to a 25k mile used gt2560r w/ BEGi manifold and downpipe for my current setup?

Benefits vs. non-benefits?

I understand it'll be quicker spool, but does it fall flat up top? Should I even worry about that since I'll rarely see redline? What is the most boost/HP I could attain w/ a 2560r if I ever wanted to go faster (which seems to happen to all junkies)??

Let's see if I understand what you're saying. You're only talking about trading your turbo kit for the one you mention; right? If that's the case, I'd jump on that chance.

The 2560r will get you to 300whp if you ever decide you want more. It's not going to be cheap but; Paul has done it. Look for some of his threads.

Zabac 03-08-2009 10:42 PM

Jump on that deal asap, as long as the GT is not shot obviously.
Begi makes one of the best mani/DP that you can buy.

hustler 03-09-2009 12:10 AM

my car makes 1BAR / 252wtq at 4000rpm and everyone on this form thinks its too late. I don't, but there is a little lag (throttle response is lag, not boost threshold).

Project84 03-09-2009 07:21 AM

Hustler, 1 bar as in 15psi? And, I don't know what turbo you have, so if you could provide that info I could get the full picture.

I realize the quality of the BEGi parts is higher than my ebay parts, no doubt there, at least if the old saying "You get what you pay for" holds true.

I'm not sure if this person is wanting to trade a BEGi DP or just a custom one, that part wasn't made clear.

I guess the real question here is, being I'm wanting to stay on a tight budget w/ this car (for now anyway) and have no plans of rebuilding or upgrading the bottom end, which turbo would suit me better? My T3/T4 .63 A/R w/ OBX manifold, or a gt2560r w/ Begi mani? I wasn't really considering the trade at first because I just want to drive the car and not mess w/ anything I don't need to, but if this is widely suggested, maybe I'll spring for it.

EDIT: This is tough! Seems like some people don't mind lag, particularly those who live with it, and some people hate it; those who don't have to deal with it.

What is safer for the 175k mile bottom end? To roll into the boost, as with a smaller turbo? Or is it more of a boost is boost, it doesn't matter, kind of situation?

evank 03-09-2009 07:28 AM


Originally Posted by Rafa (Post 379232)
Let's see if I understand what you're saying. You're only talking about trading your turbo kit for the one you mention; right? If that's the case, I'd jump on that chance.

The 2560r will get you to 300whp if you ever decide you want more. It's not going to be cheap but; Paul has done it. Look for some of his threads.

If the OP wants quick spool and only 200hp, then wouldn't he be better off trading for the 2560, then selling or trading the turbo itself for a 2554?

Project84 03-09-2009 07:31 AM

I just want whatever will benefit me the most with a stock bottom end (thought it would be best to not pass 10 or 12psi if I plan on keeping the rods straight) and using the car on the street, where it will rarely see redline.

It seems like there is enough "want" for these 2560's that I could trade it later if I got bored with it, am I correct in thinking that?

Rafa 03-09-2009 07:33 AM


Originally Posted by evank (Post 379344)
If the OP wants quick spool and only 200hp, then wouldn't he be better off trading for the 2560, then selling or trading the turbo itself for a 2554?

evank, the OP just said he's looking for which one is safer to run. If I were in his shoes, I'd stick with the T3/T4; this way he'll see "boost threshold" (happy hustler? :giggle:) later but, he'll have much less backpressure.

FWIW, I've always thought that the 2554 is a little too small for our application but that's just my opinion; and you know what the say about opinions: "opinions are like belly buttons, everybody has one". :)

evank 03-09-2009 08:18 AM

I base most of my turbo opinions from my education at the School of Paul.

LOL, but we haven't gotten to the chapter about "safety" yet, except for urgent stuff like AFR. :)


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