Need timing table for 20 psi and 1.6
#21
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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...
#22
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Since we are speaking on cut, have either of you experienced fuel or spark cut? If so, what does one experience when this happens? I know the car will stop pulling or whatever, but is there a pop or some other indication that tells you this happened
#23
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...
#24
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Generally no pop or noise. A full cut means no combustion. It would feel the same as if your car just turned off. It's also not like a rev limiter where the car will just stop pulling, the first time you will hit it you will think something broke because it's a hard cut.
#25
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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...
you should only ever hit it if something was ever majorly wrong--like the boost source on your wastegate fell off--and like it would kick in so quickly, there's very low chance of any damage.
take my setup for example: i was running about 14psi at peak torque, but my turbo tapered off past 6k, so I actually increased boost to 16psi by redline.
if I set my boost cut to 16psi, it would always hit as I neared redline (remember the code is predictive -- especially on quick ramp ups as boost is building).
Even if I set it to 18psi and my turbo wildly spooled up to 18psi -- the boost cut would kick in so quickly (probably around the 15-16psi zone and we are talking split seconds) I highly doubt any damage were to be done... It's a failsafe, so treat it like such.
I set hard stops of timing and fuel in my tunes too.
example, I ran 215kPa. so i had a timing row of 220kPa just above it, then another of 255kPa.
Since MS interpolates, I'd keep the 220 row, just above, very close to my 16° timing. If I made the row just above 215, 255, then there's a change my final timing wouldn't actually be what I demanded in the table.
But the 255 row would drop down a bunch, so the MS would reduce timing significantly as the boost would ever increase over 215. I'd do something similar in the fuel table, so there'd be like 10-20% more fuel up top above where I normally ran as a way to basically reduce power/torque and keep the motor safe in an "oh ****" moment.
Last edited by Braineack; 05-22-2018 at 11:12 AM.
#27
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retard timing above your boost level too.
you should only ever hit it if something was ever majorly wrong--like the boost source on your wastegate fell off--and like it would kick in so quickly, there's very low chance of any damage.
take my setup for example: i was running about 14psi at peak torque, but my turbo tapered off past 6k, so I actually increased boost to 16psi by redline.
if I set my boost cut to 16psi, it would always hit as I neared redline (remember the code is predictive -- especially on quick ramp ups as boost is building).
Even if I set it to 18psi and my turbo wildly spooled up to 18psi -- the boost cut would kick in so quickly (probably around the 15-16psi zone and we are talking split seconds) I highly doubt any damage were to be done... It's a failsafe, so treat it like such.
I set hard stops of timing and fuel in my tunes too.
example, I ran 215kPa. so i had a timing row of 220kPa just above it, then another of 255kPa.
Since MS interpolates, I'd keep the 220 row, just above, very close to my 16° timing. If I made the row just above 215, 255, then there's a change my final timing wouldn't actually be what I demanded in the table.
But the 255 row would drop down a bunch, so the MS would reduce timing significantly as the boost would ever increase over 215. I'd do something similar in the fuel table, so there'd be like 10-20% more fuel up top above where I normally ran as a way to basically reduce power/torque and keep the motor safe in an "oh ****" moment.
you should only ever hit it if something was ever majorly wrong--like the boost source on your wastegate fell off--and like it would kick in so quickly, there's very low chance of any damage.
take my setup for example: i was running about 14psi at peak torque, but my turbo tapered off past 6k, so I actually increased boost to 16psi by redline.
if I set my boost cut to 16psi, it would always hit as I neared redline (remember the code is predictive -- especially on quick ramp ups as boost is building).
Even if I set it to 18psi and my turbo wildly spooled up to 18psi -- the boost cut would kick in so quickly (probably around the 15-16psi zone and we are talking split seconds) I highly doubt any damage were to be done... It's a failsafe, so treat it like such.
I set hard stops of timing and fuel in my tunes too.
example, I ran 215kPa. so i had a timing row of 220kPa just above it, then another of 255kPa.
Since MS interpolates, I'd keep the 220 row, just above, very close to my 16° timing. If I made the row just above 215, 255, then there's a change my final timing wouldn't actually be what I demanded in the table.
But the 255 row would drop down a bunch, so the MS would reduce timing significantly as the boost would ever increase over 215. I'd do something similar in the fuel table, so there'd be like 10-20% more fuel up top above where I normally ran as a way to basically reduce power/torque and keep the motor safe in an "oh ****" moment.
#29
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Understood. I just made a discovery. Tested my tial wastegate actuator and noticed air was going thru it and blowing out the other side. I opened it and noticed the diaphragm was offset. Fixed it now its working. With that being said Im sure my wastegate was never opening. It could still use some porting for sure.
oh yea, with the larger turbo and a shitty 90* bend down pipe it made 214 rwhp and 179 rwtq. I’ve since replaced the down pipe and now have swapped the turbo. I’m going to port it a little before I reinstall. Should be able to control boost now since I’ve got the actuator working. I’m going to take it back to the dyno once it get the boost situated
oh yea, with the larger turbo and a shitty 90* bend down pipe it made 214 rwhp and 179 rwtq. I’ve since replaced the down pipe and now have swapped the turbo. I’m going to port it a little before I reinstall. Should be able to control boost now since I’ve got the actuator working. I’m going to take it back to the dyno once it get the boost situated
Last edited by mx5newbie; 05-22-2018 at 01:28 PM.
#30
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Got it all back together. It’s now making 11-13 psi and it feels good. Quick spool and runs great. Thanks guys for all your honesty and help. I will not touch it until I can get it on the dyno
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