Need timing table for 20 psi and 1.6
05-21-2018, 04:56 PM
#1
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Need timing table for 20 psi and 1.6
i recently swapped out my turbo for a smaller Turbo. Where I was originally making 14 psi max at 7k rpm, I’m making around 18 or so psi at 6500 rpm or so. Fuel looks good. Just want to see what a timing table should look like in this case. This is my daily driver and I do not see max boost on a weekly basis, but would like to know I’d be ok if I did want to. What max total timing should I be at during WOT? Thanks in advance. This is on a 1.6
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05-21-2018, 07:04 PM
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Why is there so many mixed reviews on this subject. Some say they have run 20 psi on stock bottom end and stock compression with no issues. Then there are reviews like this. My engine has 323 GTX rods and pistons and my compression is lower. I know they aren’t that much better than stock, but what’s the separation with this?
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05-21-2018, 07:18 PM
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Hey at least someone does around here. :P
But really, you didn't end up with a stronger motor with the 323GTX stuff. Just one that will respond worse on the way to bending rods. Same "danger point" as you had with Miata internals.
Find out how many power you're making, then evaluate from there.
But really, you didn't end up with a stronger motor with the 323GTX stuff. Just one that will respond worse on the way to bending rods. Same "danger point" as you had with Miata internals.
Find out how many power you're making, then evaluate from there.
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05-21-2018, 07:38 PM
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Hey at least someone does around here. :P
But really, you didn't end up with a stronger motor with the 323GTX stuff. Just one that will respond worse on the way to bending rods. Same "danger point" as you had with Miata internals.
Find out how many power you're making, then evaluate from there.
But really, you didn't end up with a stronger motor with the 323GTX stuff. Just one that will respond worse on the way to bending rods. Same "danger point" as you had with Miata internals.
Find out how many power you're making, then evaluate from there.
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05-21-2018, 07:42 PM
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Well I have a tial wastegate actuator with a 10 psi spring but it appears I’m experiencing boost creep. I have thought about putting the 8 psi actuator on it that came with the turbo
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05-22-2018, 01:13 AM
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I was thinking about something. I have overboost protection in msq, so until I get this figured out, can I simple set my kpa to 205 or so to cut fuel. Is that not what it’s designed for? I checked it as it sits now, it’s like 227 kpa and cutting spark. Am I figuring this correctly. I’ve read where this figure is kpa-100/6.85 to get the proper psi for the overboost protection. If that’s correct, it’s now to to protoect around 18.5 psi. Any advice will be appreciated. Thanks
Last edited by mx5newbie; 05-22-2018 at 01:51 AM.
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05-22-2018, 08:52 AM
#16
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its going to suck to drive and constantly hit a fuel cut.
there's only mixed reviews here coming from one Ford Escort shop...
Here's a law we live by here: Miata rods are weak bananas past 250rwtq.
with your CR and rods you can probably get away with a lot more. But stock, no way. and everyone here will agree.
Start with a miata basemap, and advance it until you hear knock with your detcan and then tell us what it can take...
Why is there so many mixed reviews on this subject. Some say they have run 20 psi on stock bottom end and stock compression with no issues. Then there are reviews like this. My engine has 323 GTX rods and pistons and my compression is lower. I know they aren’t that much better than stock, but what’s the separation with this?
Here's a law we live by here: Miata rods are weak bananas past 250rwtq.
with your CR and rods you can probably get away with a lot more. But stock, no way. and everyone here will agree.
Start with a miata basemap, and advance it until you hear knock with your detcan and then tell us what it can take...
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05-22-2018, 09:06 AM
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its going to suck to drive and constantly hit a fuel cut.
there's only mixed reviews here coming from one Ford Escort shop...
Here's a law we live by here: Miata rods are weak bananas past 250rwtq.
with your CR and rods you can probably get away with a lot more. But stock, no way. and everyone here will agree.
Start with a miata basemap, and advance it until you hear knock with your detcan and then tell us what it can take...
there's only mixed reviews here coming from one Ford Escort shop...
Here's a law we live by here: Miata rods are weak bananas past 250rwtq.
with your CR and rods you can probably get away with a lot more. But stock, no way. and everyone here will agree.
Start with a miata basemap, and advance it until you hear knock with your detcan and then tell us what it can take...
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05-22-2018, 09:16 AM
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Boost pressure is a worthless measure. It is a measure of backpressure in the system. It is possible to switch turbos, run 10 more psi, and make less power. LBS of air passing through the engine is the actual measure of power. If you double the air, you can double the fuel to match, and then make roughly double the power. If the engine or turbo can't pass as much air as you are trying to put through it, you end up compressing the air more and more thereby increasing the boost pressure (or backpressure).
Timing bends rods even at lower boost levels. Cylinder pressure at particular crank angles is a result of timing. Some crank angles are more forgiving for a given amount of cylinder pressure than others. But generally, about 250wtq will be the limit for favorably timed engines with any rods that came from Mazda.
Timing bends rods even at lower boost levels. Cylinder pressure at particular crank angles is a result of timing. Some crank angles are more forgiving for a given amount of cylinder pressure than others. But generally, about 250wtq will be the limit for favorably timed engines with any rods that came from Mazda.
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05-22-2018, 09:45 AM
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if youre running MS, it will cut fuel if it *thinks* youre going to hit that boost level -- it looks at the trend and cuts fuel before the limit. either way, it's still unpleasant when you hit one -- I always liked to keep a boost cut 3-4psi above my boost level.
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05-22-2018, 10:01 AM
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Somewhat off-topic but 3-4psi seems like a lot? In going from 8psi to 10psi I went from 220whp/200ftlbs to 250whp/220ftlbs. It would seem that a boost spike to 14psi would be nearing engine-grenade territory? Fuel cut is unpleasant, but less unpleasant than noodle rods...
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