Turbo too small?
#21
Boost Czar
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this.
if you want 140-150hp, buy a 1.8 VVT.
the SR20 T25 is not a fast spooling turbo on a 1.6L (really, nothing is)
here's the SR20 T25 on a 1.8L vs a 1.6l:
![](https://www.miataturbo.net/attachments/diy-turbo-discussion-14/168533-turbo-too-small-80-blob_03177588c30e51b7876634d7caee8f32e0e72bba.png?dateline=1460817617)
even something small like a GT2552 cant spool well on a 1.6L miata:
![](https://www.miataturbo.net/attachments/diy-turbo-discussion-14/168532-turbo-too-small-80-miatadyno2_7e8e6d0b6de97249970e9ae39983357ae47c18db.jpg?dateline=1460817523)
the cam profile prevents it.
1.6L turbo setups are ******* stupid. the 1.6L motor is complete dogshit. :P
if you want 140-150hp, buy a 1.8 VVT.
the SR20 T25 is not a fast spooling turbo on a 1.6L (really, nothing is)
here's the SR20 T25 on a 1.8L vs a 1.6l:
![](https://www.miataturbo.net/attachments/diy-turbo-discussion-14/168533-turbo-too-small-80-blob_03177588c30e51b7876634d7caee8f32e0e72bba.png?dateline=1460817617)
even something small like a GT2552 cant spool well on a 1.6L miata:
![](https://www.miataturbo.net/attachments/diy-turbo-discussion-14/168532-turbo-too-small-80-miatadyno2_7e8e6d0b6de97249970e9ae39983357ae47c18db.jpg?dateline=1460817523)
the cam profile prevents it.
1.6L turbo setups are ******* stupid. the 1.6L motor is complete dogshit. :P
Last edited by Braineack; 04-16-2016 at 10:41 AM.
#22
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I'd say go for it if you can fab all your own parts. Boost threshold will be low and vertically no lag in any normal street driving rpm range. However the fact that your asking instead of posting pics of your homemade manifold with the turbo having off tells me this my not be the way for you. It will end up costing you more to pay others to do your fab work than it would to buy quality used, known to work parts.... FM mani, down pipe, and 2554.
Also you will change the way the engine wants to run. It will probably start to sign off by about 5k and really be falling hard by 6. This means you've basically lowered your usable rpm by about 1000 rpm. You could probably tune a boost controller keep the boost up a bit in the upper rpms, but you will most likely be over spinning the turbo... So reliability becomes an issue.
Of course this is speculation as I've not seen the compressor map for your turbo in question. However I have seen and driven a K03 from a late 90's 1.8t Audi/VW on a 1.8 Miata. The car was a great street car at 5psi. But it wanted to be short shifted due to falling boost (and of course torque) past 6k. Which was fine because there was plenty more lower rpm torque to be found in the next gear. Kind of like a little 4 cylinder muscle car. 5 psi by 1800 rpm dropping to 4 at about 6k. Torque was plenty useable. It was to the right of the compressor map by about 6500rpm.
So if you want to do it and can fab your own parts, go for it. But know there will be limitations right out of the box. A used fm mani and a 2554 is a lot more suited to this engine though and will probably cost about the same.
Also you will change the way the engine wants to run. It will probably start to sign off by about 5k and really be falling hard by 6. This means you've basically lowered your usable rpm by about 1000 rpm. You could probably tune a boost controller keep the boost up a bit in the upper rpms, but you will most likely be over spinning the turbo... So reliability becomes an issue.
Of course this is speculation as I've not seen the compressor map for your turbo in question. However I have seen and driven a K03 from a late 90's 1.8t Audi/VW on a 1.8 Miata. The car was a great street car at 5psi. But it wanted to be short shifted due to falling boost (and of course torque) past 6k. Which was fine because there was plenty more lower rpm torque to be found in the next gear. Kind of like a little 4 cylinder muscle car. 5 psi by 1800 rpm dropping to 4 at about 6k. Torque was plenty useable. It was to the right of the compressor map by about 6500rpm.
So if you want to do it and can fab your own parts, go for it. But know there will be limitations right out of the box. A used fm mani and a 2554 is a lot more suited to this engine though and will probably cost about the same.
#24
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Not sure what else I can do, supposedly I should be able to get another 4PSI out of this thing. I bought it running 5 PSI originally, tweaked it and now @ 10PSI. Drive it till it "pops" is my plan, then maybe upgrade. My setup is a band-aid style, but if it works, don't **** with it right?
"It's not what you have, it's how you use it"
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#25
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Hey, I resemble that remark! My 92 Miata w/ TD-04, HUGE intercooler, and Bipes APU work great -- no trick ECU or programmable stuff, this is just hard-wired and self-tuned. Boost goes 5-10PSI from ~3000 RPM to 7500 (red-line). Performance is acceptable, though we always want more. A 2007 BMW M3 got me but just barely. Spent $1,000 on the car (came turbo'd) and about $700 in fixing suspension and various other problems not relating to the engine.
Not sure what else I can do, supposedly I should be able to get another 4PSI out of this thing. I bought it running 5 PSI originally, tweaked it and now @ 10PSI. Drive it till it "pops" is my plan, then maybe upgrade. My setup is a band-aid style, but if it works, don't **** with it right?
"It's not what you have, it's how you use it"![](https://www.miataturbo.net/images/smilies/smile.gif)
Not sure what else I can do, supposedly I should be able to get another 4PSI out of this thing. I bought it running 5 PSI originally, tweaked it and now @ 10PSI. Drive it till it "pops" is my plan, then maybe upgrade. My setup is a band-aid style, but if it works, don't **** with it right?
"It's not what you have, it's how you use it"
![](https://www.miataturbo.net/images/smilies/smile.gif)
07 m3 runs low 13's at 109mph
You're not even getting close to that trap speed in a janky band aid 1.6 miata.
Like, not even in the same zip code in a race. He'd have to be short shifting the car or flat out just messing with you to lose.
Last edited by 18psi; 04-30-2016 at 01:13 PM.
#27
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If you wanna know what can you do to an engine with a too small turbo, just look at the first post in my build thread: https://www.miataturbo.net/diy-turbo...p-miata-79849/
tiny turbo in most cases means tiny wastegate port, and so creep. Lots of. And creep to 18 psi at 3000 rpm isn't cool, it simply makes a big hole in the hottest piston
buy a 2554, it's common, cheap and it spool very fast
tiny turbo in most cases means tiny wastegate port, and so creep. Lots of. And creep to 18 psi at 3000 rpm isn't cool, it simply makes a big hole in the hottest piston
buy a 2554, it's common, cheap and it spool very fast
#29
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Sorry to pee in your cheerios, but:
07 m3 runs low 13's at 109mph
You're not even getting close to that trap speed in a janky band aid 1.6 miata.
Like, not even in the same zip code in a race. He'd have to be short shifting the car or flat out just messing with you to lose.
07 m3 runs low 13's at 109mph
You're not even getting close to that trap speed in a janky band aid 1.6 miata.
Like, not even in the same zip code in a race. He'd have to be short shifting the car or flat out just messing with you to lose.
Edit: It is an 04 M3, not an 07.
Last edited by SoLoOne; 04-30-2016 at 08:57 PM. Reason: update
#33
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The problem is that you're a ricer.
You think that just because you beat the driver of that car for whatever reason, that it's ok to go around and say that your 1.6 band aid miata can walk a m3.
that's nonsense.
we all know here what a band aid 1.6 miata runs and what a properly driven m3 runs. many here even have both cars.
I'll go race a bugatti veyron tomorrow in my son's big wheel, and come back and tell you guys "It's not what you have, it's how you use it"
herp derp
buying a 1.6 is strike 1. putting band aids on it is strike 2. talking about beating cars that trap 10mph more is strike 3.
3 strikes and your argument is invalid. have a nice day
You think that just because you beat the driver of that car for whatever reason, that it's ok to go around and say that your 1.6 band aid miata can walk a m3.
that's nonsense.
we all know here what a band aid 1.6 miata runs and what a properly driven m3 runs. many here even have both cars.
I'll go race a bugatti veyron tomorrow in my son's big wheel, and come back and tell you guys "It's not what you have, it's how you use it"
herp derp
buying a 1.6 is strike 1. putting band aids on it is strike 2. talking about beating cars that trap 10mph more is strike 3.
3 strikes and your argument is invalid. have a nice day
#35
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The problem is that you're a ricer.
You think that just because you beat the driver of that car for whatever reason, that it's ok to go around and say that your 1.6 band aid miata can walk a m3.
that's nonsense.
we all know here what a band aid 1.6 miata runs and what a properly driven m3 runs. many here even have both cars.
I'll go race a bugatti veyron tomorrow in my son's big wheel, and come back and tell you guys "It's not what you have, it's how you use it"
herp derp
buying a 1.6 is strike 1. putting band aids on it is strike 2. talking about beating cars that trap 10mph more is strike 3.
3 strikes and your argument is invalid. have a nice day
You think that just because you beat the driver of that car for whatever reason, that it's ok to go around and say that your 1.6 band aid miata can walk a m3.
that's nonsense.
we all know here what a band aid 1.6 miata runs and what a properly driven m3 runs. many here even have both cars.
I'll go race a bugatti veyron tomorrow in my son's big wheel, and come back and tell you guys "It's not what you have, it's how you use it"
herp derp
buying a 1.6 is strike 1. putting band aids on it is strike 2. talking about beating cars that trap 10mph more is strike 3.
3 strikes and your argument is invalid. have a nice day
Last edited by SoLoOne; 05-01-2016 at 05:40 AM. Reason: misspelling
#37
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You read way more into the message than what I wrote. Again, wonder why I bother here. I bought the car as a toy. Never said I could walk an M3. I just shared an experience while looking for advice on where to go next. Hope the ridicule helps others, sure doesn't help to tell people everything they did wrong. But whatever gets you off.
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