Miata Turbo Forum - Boost cars, acquire cats.

- Engine Performance (https://www.miataturbo.net/engine-performance-56/)

- - is 15 psi crazy or stupid? (https://www.miataturbo.net/engine-performance-56/15-psi-crazy-stupid-63142/)

Quote:

Originally Posted by Techsalvager (Post 827772)

how is it safer

More timing = higher chance of breakage if you have detonation. More timing also can = detonation.

Quote:

Originally Posted by samnavy (Post 827782)

With your conservative tune, you might only be making 180-190whp at 15psi... but you could achieve that same 190whp at 10psi with a less conservative but more optimal tune. That same "optimal" tune at 15psi will get you closer to the 220whp accepted upper limit of a GT25r on a stock 1.6.

I'd rather run a better tune at lower boost... better tune means quicker spool and smoother overall operation. I'd spend a couple hundred bucks to have a good tuner put it on a dyno and tweak you a couple good maps... I bet you'd find that right now, you could have more power on less boost with a still acceptable margin for safety, better engine response, and better overall reliability.

Yes more timing (tune) means quicker spool but again, it is less safe. Thing is though, a turbo that small will be spooling very quickly regardless of the timing.

Well she is runnign well. 15psi is nice. I hit it about 4k I was hoping it would be sooner. I am trying to tune it to hit around 3500 but no luck yet.
The boost drops down over 6k so I have turned up the duty cycle on the ebc solinoid there and it only drops to 13psi.

anywayn its great very fast

If you're not hitting 15psi until 4k rpm, there is something wrong with your setup. You should be fully spooled at least 500rpm earlier... maybe as much as 750rpm, but it's good to see that you know that.

What exhaust are you running?

Maybe if you posted up your fuel/spark tables, somebody could help see if there's a big hole somewhere in it.

I'm with Sam, on that turbo you should be hitting 15psi much sooner, even on a 1.6. You may want to check over your charge piping and make sure you don't have a boost leak somewhere.

Here are my tables. I feel like before I was hitting 11psi what it was set to 11ps at 3k or before.

Darn they will not load. I will search how to load them and be right back

Here is the whole msq I am looking into how to post just the tables

Quote:

Originally Posted by 90 Turbo (Post 827993)

What gear are you hitting 15psi@4000RPM in?

Sam he has swizzle stick size exhaust.

For a reference data point, with my GT3071 at 4000RPM in my 1:1 gear I was at 20psi.

With my Borg S366 in my 1:1 gear at 4000RPM I am at about 15psi :) In technical terms that means I rape your face. :)

Spool can greatly vary by your boost control method. Also the length of your boost signal line can affect spool by 500RPM. Same with location... All this tuning stuff has a LARGE impact and is often overlooked.

Anyways this shi doesn't really matter because if you enjoy your car you enjoy it.

Damn, doesn't that little thing completely spools >3k rpm? My crappy non-ball bearing 2870 churbo is fully spooled >4k rpm.

Tiny exhaust pipe = poor spool.

Wow, but that's kinda a big toll on a turbo that size.