Questions for guys running 12-15 psi.
 

I'm at 10psi and the car runs and performs Toney the tiger GRRrrrreat!

I always want more power. And was thinking of turning the boost up. I know that 12psi should be the peak for dependability.

But when you cross that line. How long does it last. Does it really give the motor a beating. I have a good running 1.6L, some lifter tick when it starts up. But it goes away like everyother 1.6L.

Will the motor just give up the ghost, or the rings wear out fast.
I know you can't predict everything that will happen. And I know differant motors will have differant parts fail.

But on average, with practically no track racing, lots of heavy foot street driving, shifting at 6500 instead of 7200, And then the occasional all out street race. How Long do you predict it to last.

This is a daily driver.

---------------------------------
I may leave it a 10psi for dependability, and set 14-15 psi on the ebc with a toggle switch.

You oppinions are welcome.
Even UrbanShoots But sex. Since we are there. Dr 90210 finnally explained how women get a penis in a sex change!

I boosted my daily driver 94 because I was sick of it feeling so slow compared to my already turbo'd 94. I threw a BEGi S kit on it at 250k miles in May of '08. The motor is original. I'm horrible with maintenance on it because I drive so much and 3000 miles goes by so quick. Usually I get it by 4000 but sometimes I go 5. The car now has 267k miles and I have my boost controller set to bring me to 15lbs as early as possible and hold it to redline. On cold days it makes a lot more boost a lot sooner and I've been bouncing off the boost cut of 225kpa. Yesterday I changed that to 240 cuz I hate when it does that. So yeah, I'm throwing 15 lbs at this motor with spikes up to 18 and it's still going and I beat on the thing. I do use some oil but it used oil before the turbo went on too. I think as long as you keep your intake temps under control and avoid knock and run safe AFRs they can be pretty reliable over 12psi.

And the toggle switch is a great idea. With switch off I make 11-12 in warmer weather, switch on is 15. With temps in the 40s last week it was making 15 with the switch off. For switch on I cut my DC values all down to keep it at 15, it just makes it a lot sooner. Until someone gets this closed loop boost control working I have 3 different Boost DC Target tables for different ambient temps.

I wish someone would, I tried but failed... and hitting boost cut whenever its under 60 degrees sucks


oh and for the OP, 14 to 15 psi for like 10k miles now, and its doing fine. Just have a good tune and your set.

this is why i like my solenoid switch. in the least I can fail to wastegate when it's too cold and I overboost when it's colder and i havent changed my map.

And that's why I'll be running MBC until someone figures it out or I'll buy a different EBC controller all together.

To the OP I'd say you're not really crossing any defined lines. Reliability is a function of many variables. If you knock stuff will break fast. If you do everything you can to keep that from happening and keep the engine well tuned, it should hold up fine. Drivetrain reliability will go down with added power, but you can make up for it with mechanical empathy. Some like the idea of low/high boost. I personally would rather have high all the time.

I just wish that wasn't the only way to do it. I am tuning my EBC a little bit at a time, and this time of year there is a 30 degree difference over the course of a day, and more than that in a week. This temperature difference makes for difficult tuning.

+1 for drivetrain going first.

yeah but wastegate = slow boost onset and lower boost overall. I dont want the car to be slower in the cold (would prolly help traction tho haha). I want my cake and to eat it too.

It's not that bad on wastegate - 206rwhp ;)

Attachment 210367

the main thing is I can prevent overboost till the next time I have the laptop to low my DC%.

If it's that much trouble, I'll just use the manual boost controller.

I'll turn the nob a little. LOL

I'm not becoming speedracer, just Racer X. LOL

I maintain my cars very well, and I show empathy durring daily driving. But I don't show empathy while racing. lol.
So I guess it will work. I drive my car about 30,000 miles a year.

And the weather in Texas changes continually all day. Manual controller it is.

Honest to God... I called FM early last week and asked them how I could fix this cold weather overboost problem, and they told me to get a manual boost controller... So a $40 part is better than the EBC on the Hydra. Man I wish I would have known that when I bought this kit :vash:

Back on topic, turn the boost up. 12 is more of a soft limit on a 99. Many NAs here run up to 15 with few issues. Of course I assume no liability if you blow your stuff up ;)

you could use the solenoid in conjunction with the mbc ;)

You have an overboost problem in cold weather with the Hydra? I thought they had a closed loop system that worked well. a KPA target map. Y8s?

You'll still have the same cold weather problems with an mbc. The car will make more boost when it's colder. Even without any boost controller you can have the problem. If i wanted no more than 12psi on my car I would be over shooting that with just the wastegate pressure when it gets cold. In 40F ambient wastegate pressure is 15psi for me. Tell me how to fix that with an MBC.

Just an idea here, would taping a piece of, say....cardboard over 50-60% of the FMIC have any effect? it would reduce the cooling abilities of the I/C in cool weather and with some tuning on how much is covered could get you back to the same cooling abilities in cool weather as you have in warmer weather.

Not cooling the air AFTER the turbo isn't gonna help. The warmer air would be of even higher pressure. Now maybe if we warmed the air before the turbo....

a la DEI

HEH? I thought colder air being more dense was a pretty universal statement? Thus making the air less cool (warmer) would DEcrease the pressure?

more dense as in more oxygen per unit of volume. well more everything per unit of volume.

what happens to your tire pressure when you drive the car? as the tires heat up it heats up the air and the pressure goes up.

Didn't think about it that way, oh well, it was a thought.

That's why people speak of pressure loss across an intercooler. That and I guess maybe some loss due to friction through the IC. The pressure before and after the IC are not the same. Pressure after IC is lower.

Ok I don't get this one. Why would you have more boost when it's colder? Is this because you have an internal gate that references boost at the compressor not the intake manifold?

My thought was if a MBC is used, you could set it to wastegate levels. (In our cases that is 11-12psi.)

So if the solenoid is causing overboost one cold morning, you flip the switch and fail to a MBC at wastegate levels. Wouldn't hurt your performance as much as failing completely to wastegate.

Someone a lot smarter than me can probably explain the physics behind it but I like to look at things logically so lets think about this scenario.


You wire your internal wastegate flapper door open. You car can still make some boost, maybe 1-3 lbs typically. My daily for reference was making 5 to 6 when I lost the end of the adjustable arm Friday night. It was around 60F. Now we've completely taken the wastegate actuator and any boost controller out of the equation along with where it references boost. Now what happens when the ambient temp drops to 40F? Boost goes up. Ambient temp rises, boost goes down.

So we can see there is always gonna be variation in how much boost the car makes depending on the ambient temps. Therefor the only thing we should expect to control is how high it can go over and above that amount. The way the open loop control in MS works is it controls the solenoid at a certain duty cycle based on current RPM and Throttle position regardless of how much boost is actually currently being made. So if ambient temps change a lot this method of control is not very consistent. A feedback control system would work better. If the solenoid was controlled based on RPM, TPS and what the actual boost level is we could avoid this varying ambient temp issue, as long as the boost level desired is over what the turbo will produce with no boost control.

I prefer the set overboost to 18 psi, tune for 13 psi at like 70* ambient and then let it do w/e the hell it wants with weather changes :)

I think Paul's method of haveing a couple different maps for different temps is the best we can do with MS. I agree it is annoying as hell. I've got a question. Right now I'm running 14psi and letting it shoot to 15ish. My top KPA row is 212. If I set my EBC to 15psi it'll probably shoot higher than my top kpa row. I guess this a problem? MLV can't really tune that high without a cell up there? So should I be adding something like a 230 KPA row if I want to increase the boost to 15 psi?

edit: Now that I think of it, Paul, how the hell are you not completely maxing out the injectors when you overshoot to 18psi?

My top rows are at 230kpa.

I am maxing out my 460s. I have a Vortech sitting here waiting to be installed because
1. it was much cheaper than buying and cleaning 550s.
2. i think there is something to be said for higher fuel pressure with smaller injectors. better atomization, more instant fuel.
3. the 460s should idle better than 550s although I don't have idle issues with 550s on the other car.
4. they are already in the car.

So since this has turned into an EBC thread; what needs to be done for somebody to fix the closed loop control? Is it just getting the right settings, or a new version of firmware, or can MS1 just not handle it?

I've hit 90% DC at ~7k RPMs at 15psi and an AFR of 11.5 on my 550s. I think I've I wanted to go any higher in boost I'd have to lean out things to 11.8

I like this thought process.

+1. I'm doing something similar with 550's. Got a 30-100 PSI 1:1 Mallory FPR that's going in when I put the 255HP in and block off the stock in tank regulator. Probably set it to ~70PSI at atmospheric pressure. That will keep a 70 PSI delta at all times. My setup will be different, but in the end it will accomplish the same thing on my 99'. Higher pressure, more fuel, better atomization, more headroom, etc.

MSI doesn't support it. I have no idea if someone smart could write the code to make it suppport it. I would be it's completely possible. I got a feeling MS2 would support it more easily. Gotta talk to Abe about it one day, he knows more about MS2 than I.

there is a thread on msextra.com discussing how to fix it. it involves a code rewrite and some people have offered to tackle it. every couple of days there is another post but so far no fix. Boost Control change request

hell, I'd be happy with dual DC% table switching. I bet it's as simple as making some changes in your .ini file

what I don't understand is why the Hydra or other controllers can't automatically adjust the boost levels due to outside temperature. Maybe this is the closed loop solution being discussed above. It is very annoying when I get overboost in the morning driving to work and crappy performance heading home... And this is LA with some of the most stable temps in the nation! What is this car going to do when I get back to the midwest and there is +- 20F changes every couple of days. ARGH!

It doesent seem like it would be hard to have MS use a KPA table for the boost control. I mean it has the feature, but it doesent hold a steady boost/work well. Can the processor not handle it or is the code just not well written?

The tempture compisation is a neat idea too, add or subtract boost DC% depending on air intake temps.


And finally, yeah I would be veryyyyy happy if they could just code it so that you have like 2 or 3 switchable DC% maps. I would think that would be easyer than both ideas above, and still work pretty good.

This morning my car boost went to 12psi. Oh -yea. I have a weak clutch and it spun through first and fish-tailed in 2nd. It will be hard not to turn it to 14psi.

Cardriverx, did you build your motor? Or is the stock 1.6L holding 14psi on a T3?
I bet that is wild in boost.

I haven't had any crazy variations in boost level running closed loop on the LINK. It looks the same at 50F that it did this summer at 90F. It's not a super level curve- about a 1 psi variation from 4-7k.

I started experimenting with my closed loop boost control again today. Hopefully I'll come up with something positive.

12-16psi
 

I have been running 12-16psi for a long time now, I have a simple mechanical wastegate control, and I think I last set the spring tension in 1999...

Believe it or not, you can control boost with the accelerator pedal. When I was having misfire problems at high boost, I just (tried) to keep my foot out of it to avoid experiencing the misfires.

As far as reliability, I'm around 90Kmi now and no engine problems so far. I drive as you describe, heavy foot, but shift before 6500 most of the time. Used to race a little, but I still shifted relatively early - my racing was harder on the brakes than anything else.

Most important thing for your engine safety is to get your fueling right. When in doubt, go for the rich side of ideal. Ignition timing retard hasn't done much for me in terms of eliminating knock problems, except in the 1000-2000 RPM range near WOT. Any other map area where I've had a knock, it has been a lack of fuel problem. I can still run a bit rich at 16psi / 7KRPM with 310 injectors, it seems that most kits are coming with larger ones these days, but in a stock 1.6 motor I haven't found a need for more than 310.

If I had socked away $100 a month toward a replacement motor, starting when I installed my turbo, I could afford a pretty sweet replacement engine by now:

Flyin' Miata : Engine/Drivetrain : Built engines : FM built stroker engine

WHAT?? No wonder you had a lack of fuel problem. Without running like a 12:1 FPR there is no way you are getting enough fuel out of 310 cc injectors for 16 psi of boost. And you will make less power with the car at 12 psi at full throttle compaired to 12 psi at 3/4 throttle.



Toddcod- Yep, all stock, all 100k miles of it.

Loosely instrumented
 

It has been awhile since I did my tuning work, and I did the work off of datalogs from the LINK and a standard O2 sensor, so it's a rough guide at best, but... last time I checked, running near 15psi, I was reading rich across the band from 4000RPM up to 6500. I believe the injector duty cycle was near maxed out, but in reality, I try to keep things under 12psi most of the time anyway - over 12psi is just an artifact of cold weather for me.

I did keep my foot in it last night to test a new set of plugs and wires, and I did see 16psi - no knock or hesitation up past 6000RPM. Maybe when the kids are off to college, or at least old enough to enjoy hanging around a noisy garage all day (without getting into serious trouble), I can get the time to play on a dyno with a wideband O2 sensor, for now I just enjoy driving it.

Oh, and the way the LINK works, 12psi is 12psi, all fueling is governed by the MAP sensor which sees more or less exactly what my A-pillar gauge sees. The only affect that throttle position has is back pressure to the turbine compressor outlet. 12psi at WOT means that the wastegate is open enough to keep the turbine from making more than 12psi into the intake manifold. 12psi at 3/4 throttle indicates that there is more air pressure coming out of the compressor, and if you're not going to use that air, you could have gotten your 12psi with less exhaust back pressure because the wastegate could have been open a little wider.

Oh, and a tidbit from the past: stock 1.6 injectors are 220, and they were routinely used in turbo kits up to 7psi of boost or so (call it 7+15=22psi absolute), so, going from 220 to 310, you should be able to handle up to 31psi absolute, or about 16psi of boost.

Starting around 1998 or so, the "big boost" kit makers started running into people who were stroking their 1.8s and running 18+psi, so they quickly went up to 390s, then 440s as standard parts to avoid the label that their uprated injectors are too wimpy for real he-man power. I think they weren't really getting 390 flow out of their 390 injectors, probably due to the electrical portion of their systems, and it was a quicker / easier fix to go to a larger injector rather than fixing the the electrical drivers.

Anyone else think this mangocats is talking out his ass?

Ah, so the hazing begins....

Tanner and Cardell thought I was talking out my ass about the 310 injectors, but their standard program for the Link was lean as dry dog turds all over my map, when I scaled up master fuel for 310 injectors, it ran fine.

Believe me, or not, I really don't care.

not at all. i just found out 1.6L injectors are 220cc and are enough to support 7psi when you fix the "electrical drivers."


here's the math:

220cc = 20.95 lb/min

220cc = 43.5psi
7psi would put the rail at 57psi give or take
220cc injectors at 57psi = 252cc or 23.95 lb/min

23.95 x 85% duty cycle / .55 BSFC = 37.01 HP per cylinder

37 x 4 = 148BHP

the GT1241 can output around 15 lb/min
15 lb/min = 136BHP

so of course stock (220cc) injectors can handle a few pounds of boost through a GT1241.

Braineack, your mama must be so proud...

By running 16 psi on 330 cc injectors you either have the fuel pressure absurdly high, or are defying the laws of physics and flow calculations.

I don't follow you because I am dumb.

7psi="a few" ?

220cc=43.5psi?

7psi would increase rail pressure to 57 if the nominal pressure is 50, right? (OEM reguators are 1:1?) but the pressure differential is still 50 across the injector, so assuming you have a 1:1 pressure regulator, your injector flow at xx duty cycle will be the same regardless of boost pressure.

My default link ECU settings for the RC440's/1.6 were pig rich.

I have only read this last page so I don't really know what this thread is about. But I did learn I could control boost with the accelerator pedal. Fucking awesome. I can't wait to try.

ok let me revise my math...

220cc is rated at 43.5psi

220cc injectors rated at 50psi would now flow at 22.44 lb/min

22.44 * .85 / .55 = 34.68
34.68 * 4 = 138BHP

assuming 7psi on our little gt1241 would fully achieve it's potential on our 1.6L, then we have a good injector. :)


just laugh and stop picking my numbers apart, they were trivial, and i was trying to support his theory through the use of trickery.

Gotcha. I know what yous was up to. :) I'll agree with Paul.

RC440's at 80% duty cycle is 33.5lb/min
33.5/.55 (?) = 60.9
60.9*4=243hp

Ut oh. I guess I won't be making my 300rwhp at the dyno day. I am pretty sure my static fuel pressure is right at 43psi.

Where did you get the .55 BSFC #?

oh, "haha" :p

just run them to 100%, wont hurt nothing.


In all honesty, i dunno were BSFC should be.. i always use .55 for my math. My 460cc injectors are seeing 85% at 232rwhp and 12:1.

yeah I'm not too worried about them. I wonder what I'm doing "wrong" though to get enough fuel out of them. Must be the fuel rail ;)

If I had socked away $1 for each Braineak post, I could afford a pretty sweet replacement engine by now. hehe