Built motors and detonation
08-01-2013, 04:42 PM
#202
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Along with the forged pistons I am hoping you are getting forged rods, or already have them in the block.
No matter what after the new motor is in, you will need to take it back to the dyno and have it re-tuned.
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08-01-2013, 06:02 PM
#208
What I meant was that I didn't have any readings during the catastrophic event.
However, you did just remind me that I took logs during the misfiring shortly thereafter. I've attached it in case anyone was interested in what a 3-cylinder BP-T looks like
That I can completely agree with. Sucks having to budget by cutting corners but there are other priorities in life.
However, you did just remind me that I took logs during the misfiring shortly thereafter. I've attached it in case anyone was interested in what a 3-cylinder BP-T looks like
That I can completely agree with. Sucks having to budget by cutting corners but there are other priorities in life.
Last edited by JustinOMGWTF; 05-26-2020 at 11:12 PM.
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08-01-2013, 06:15 PM
#209
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What were the wideband readings at WOT before it grenaded?
I would do low-comp pistons and a bigger intercooler, but I'd also take 4-6* out of your timing map above ~140kpa. It's way, way, way too aggressive for pump gas. Maybe more than that if you failed and bought a 0.64a/r GT2871R.
I would do low-comp pistons and a bigger intercooler, but I'd also take 4-6* out of your timing map above ~140kpa. It's way, way, way too aggressive for pump gas. Maybe more than that if you failed and bought a 0.64a/r GT2871R.
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08-01-2013, 07:51 PM
#211
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Still kind of aggressive for 91. Might work on 93-94. The 0.64a/r turbine is not doing you any favors here - swapping to a 0.86a/r housing would let you get away with more timing and it'll make more power to boot.
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08-01-2013, 09:32 PM
#213
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The spool difference is minimal between the 0.64 and the 0.86 on a Miata. The torque difference in the midrange and the extra det threshold headroom isn't. I'd swap the turbine housing.
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08-02-2013, 12:29 AM
#217
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Having trouble finding GT2871R .64 vs .86 comparison. BUt then there's the newer GTX series:
GTX2867 .86 A/R vs .64 A/R Turbine Dyno
GTX2867 .86 A/R vs .64 A/R Turbine Dyno
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08-02-2013, 12:31 AM
#218
And yet, I wonder: is it really as drastic as you say it is. I've done a quick search and every time we talk about this, its just talk. Do you have some proof?
For the record, I'm of the same mindset as you and usually side with the larger hotside, but all MY proof and/or experience has been on other cars, with larger motors from our 1.8....So I really can't say for 110% sure when talking about a miata with a gt28xx turbo
For the record, I'm of the same mindset as you and usually side with the larger hotside, but all MY proof and/or experience has been on other cars, with larger motors from our 1.8....So I really can't say for 110% sure when talking about a miata with a gt28xx turbo
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08-02-2013, 01:32 AM
#219
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And yet, I wonder: is it really as drastic as you say it is. I've done a quick search and every time we talk about this, its just talk. Do you have some proof?
For the record, I'm of the same mindset as you and usually side with the larger hotside, but all MY proof and/or experience has been on other cars, with larger motors from our 1.8....So I really can't say for 110% sure when talking about a miata with a gt28xx turbo
For the record, I'm of the same mindset as you and usually side with the larger hotside, but all MY proof and/or experience has been on other cars, with larger motors from our 1.8....So I really can't say for 110% sure when talking about a miata with a gt28xx turbo
Not apples to apples, but close enough. The difference can be compensated for entirely by using a good tubular manifold and downpipe.
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08-02-2013, 01:59 AM
#220
Ha, even in that thread I was agreeing on the .86 being the better choice.
However, and maybe cause my plans and goals for current car have changed drastically from the previous, but I've been re-thinking my logic (and that discussion).
I don't think its a fair comparison at all:
non vvt head vs vvt head (like 500 rpm worth of lowend just in that alone)
his is also mildly worked which usually tends to improve topend at slight expense of spool
cast log mani vs one of the best tubulars (another like 300-400 or so)
race gas vs e85 (e85 promotes better spool too, dunno how much exactly)
the only slight disadvantage you have there is your high flowing honda im vs his stocker
Anywho.....I wish we had an actual apples vs apples comparison on a miata. Cause I think this is far from a clear cut open and shut discussion.
*edit: also the more I look the more I see stuff like this online:
which supports a whole lot of the claims that many make:
smaller hotside - broader torque curve
larger hotside - hits later but harder
However, and maybe cause my plans and goals for current car have changed drastically from the previous, but I've been re-thinking my logic (and that discussion).
I don't think its a fair comparison at all:
non vvt head vs vvt head (like 500 rpm worth of lowend just in that alone)
his is also mildly worked which usually tends to improve topend at slight expense of spool
cast log mani vs one of the best tubulars (another like 300-400 or so)
race gas vs e85 (e85 promotes better spool too, dunno how much exactly)
the only slight disadvantage you have there is your high flowing honda im vs his stocker
Anywho.....I wish we had an actual apples vs apples comparison on a miata. Cause I think this is far from a clear cut open and shut discussion.
*edit: also the more I look the more I see stuff like this online:
which supports a whole lot of the claims that many make:
smaller hotside - broader torque curve
larger hotside - hits later but harder
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