stock mas limit finally found?
 

some of you may have been following my progress, I've recently dyno'd the car at 700awhp on a dynojet and with increases in boost from 38psi to 45psi, only lower rpm torque increases a little, not the high rpm horsepower, a sign that there is a choke point. Increasing timing also does not make a significant improvement.

I'm interested in going with SD or a MAF-T to answer the question once and for all, how much horsepower can you make on the stock MAS.

If someone has a MAF-T intake setup I could borrow I'd be willing to spend some time dialing the tune back in and seeing if it helps reduce the restriction enough to increase the horsepower. I figure that's the quickest way to get the answer and to see if SD experimentation on the stock ECU is worthwhile for a car at this level.

Any logs? Just curious what the 2-Byte maf frequency looks like.

700 HP through that little guy is impressive. The gains of getting rid of it may be even more impressive though.

Well I've seen 8's out of a GM MAS setup.

Actually I already did the math for your car, at 38psi with no MAF it should be worth about 40-45whp. This is based on a car that is not octane limited at xx boost. Like 0xDEAD said, there are plenty of DSMs running around 750-800+ (I think of Hal Landry) with a 3" GM. DSM25psi made 762 on a Mustang (for what thats worth compared to a DJ) so there is plenty to be had.

I would switch to SD and get it over with, its the easiest overall since all you change is the tune and a MAP sensor vs having to do a different upper pipe. I imagine if you were going to leave it drawthrough you might gain some but not as much as blow through.

I didn't think SD was ready for this kind of boost

I don't log airflow, don't need it for tuning.

Well its kinda ready for any boost level any engine can take. SD works on MAP sensor voltage. How you tell evoscan to represent that voltage in the map is up to you and your skills. I know a couple places that sell 100psia MAP sensors. So as long as you can keep it below 85psi you should be ok. If you need to run more boost let me know and I'll help you source a larger sensor. :lol:

Roadspike was saying something about the 5bar pressure sensor not being sorted out yet with the stock ecu...maybe he'll chime in on that obstacle.

Its sorted for the most part I simply atm have slight tunning issues at the low load and rpm end of the spectrum where the gradiants for VE are the highest. Right now i have a slightly rich cruise issue at about 50-60 load. Nothing a few tweaks of the map and RPM VE wont sort out over time.

I'm sticking to a more 1:1 map kPa vs load rather than the scaling your car is doing where 300kPa would have been more like 360 load. In the end your load will go down on this rom so you don't have to scale it out so high. If you want its easy enough to change the load value to something more like your car is tuned with already.

I'll give you my rom setup for the 5 bar if you want chris just shoot me an email in pm. You're going to have to sort out the VE on your own car anyways since with the big head and turbo its going to be more efficient than my personal car.

Notables:
Car uses a 5 bar kalvico sensor good up to 58psi
This car hooks the air temp sensor to the fuel temp sensor for easier change out in case you want to go back for some reason.

Shoot me an email or call me Rob can give you my number.

Oh one more thing I was planning on implementing boost control on the stock ECU as well but i still need the help of MrFred for one scaling item. :)

Rock on :cool:

i wonder if you could run 2 map sensors those of you running big boost
with some sort of code to use the high resolution 2.5 or 3 bar for loads below 100 and then switch to the 5-6bar above?

interesting, I'm not too hung up on my scaling staying the same, I can adjust my timing/fuel maps as needed if it's off.

where are people getting the 5 bar kalvico sensor and cost?

can you elaborate on the iat sensor details?

I'm not interested in stock ecu controlled boost right now, maybe later.

my email is chris@mellontuning.com if you want to shoot that ROM over. another obstacle will be getting away from my beloved 96940011 ROM, I bet it's not supported.

Might be worth logging just to see what it's doing. It would show if it's a physical limit on airflow or an electrical limit. You may already be well past the electrical limit and just be tuning around it.

Here is one source:

http://www.zeitronix.com/order/order.htm#MAP50

I've seen the airflow data before on my car, it looks normal, just saying I haven't done it recently or continually.

Chris,

I've got a 5 bar kavlico and a 4 inch intake you're more than welcome to test with if you wanna come down for a date with the LS1 boys here in bham ;)

btw, I got my 5 bar from roadraceengineering along with their adapter to take the place of the MAP sensor on the intake manifold.

thanks but I'd need much more time with it to set everything up and tune than that short bama trip would allow.

aye, just figured i'd throw it out there.

I got mine personally from zeitronix and had zeitronix also make an adapter so i could just plug in the stock mdp sensor and use the aem adapter to replace the mdp with the kalvico. I got the adapter from a local vendor here and then installed the sensor using the patched supplied by MrFred and worked out some settings for it. I believe the sensor was about 130 bucks, adapter was another 30 for the wiring, and the adapter to convert it to stock mdp location was around 20 bucks if i remember everything right here.

The IAT tempt sensor is litterally your off the self GM open element sensor which can be bought pretty much anywhere. I got the sensor and bung from diyautotune.com if i can remember right. Wired it into the pin on the ecu which required me to basically run a wire to the sensor from the ecu and used the intake as the ground. My sensor is welded right into buschur's upper intercooler pipe.

Np on the ecu controlled boost I don't have it implemented anyways. I'd say i'm really close to cracking the low load issues i'm having where the tune kinda flops into lean and rich, mind you at loads under 30kPa which is like downhill light gas. If you want to wait a couple days i think i can iron it out to near perfection. Or I could just send you the tune as it is right now.

The rom is tephra 5.10 the 97140015 romid so yeah you would be losing your rom :(.

no rush on the ROM since I don't have the parts yet, I'm still hell bent on going 9's on the stock mas so I'm not quite ready for SD but I'm interested. I sure would like to get the full potential out of this turbo before I move on to a bigger one and sheet metal intake

I have already run cars out to 40psi on the 4bar and its fine. Before this I had my car on a MAFT Pro and 5 bar and it drive fine, so Stock ECU and a 5 bar should be that much better since we cut out the piggyback.

Understood I'll work on the around town drivability of this rom and shoot you an email where you can contact me. I don't think i'll need more than a couple days to figure out the ins and outs of these trailing edges.

I'll make sure to save a rom where the ecu boost isn't implement or at least tuned up to the point of being disabled.

cool, the maf-t solution is tempting because I know I can get it up and running right away for some quick results. However, I do think SD would be the best solution in the long run, it'll just take a little more homework to get it going properly.

ecu boost is fine, the solenoid doesn't' have any hoses going to it :)

Right but i believe MrFred's implementation takes over the "desired boost" table which would mean boost cut if its set too low. Really easy to disable though :).

FYI:
Using a 3 port boost control solenoid no funky boost pills here :)

ah ok, I'm sure the car will remind me to fix that if I hit a brick wall at 25psi lol :lol:

:lol: god i know that feeling too well first time i thought i broke the poor girl :eek:

Tuning SD is piece of cake how it's currently implemented. Don't shy away from it just because of that. We can help you out if need be.

In preparation, get a log of cruising around town as long as possible with boosting, etc...try to hit as many cells as possible. Make sure you are logging boost pressure (really absolute pressure, so let us know the baro if the log is gauge pressure) and baro+temp compensated load.

I can tell you your preliminary VE settings based off of that log.


Eric

Mellon.....What did you do to the MAF tune wise when you removed the screen??? I would imagine that it caused all kinds of drivability issues? How did you go around these problems.

I ask because for those of us getting closer to 30psi boost...I would hate to hose up my turbo because of the screen getting sucked in.

Sorry this was off topic....well, it's kind of related.

Thanks.

Paul

nothing major it just lowered the load a little.

What do you mean "lowered the load"? There isn't such an animal in the MAF tables. Please explain.

He means when he took the honeycomb out, that the measured load lowered.

EXAMPLE: He was logging 380 peak load before with the honeycomb in, and he took the honeycomb out and everything else the same, the logged peak load dropped to 360.

On Topic:

I'm ramping up to do a stock ECU SD conversation on a significant build here pretty soon so I will most likely be needing some help from some people in this thread shortly. :)

You want to do a 3,4,5, or 7 bar sensor build?

4 minimum, the 3 is a waste unless you already own it for logging boost. Bryan, dont be afraid to call Aaron at the shop.

4 bar will be enough, on a Evo 9 :) I'm curious if anyone is actually doing a 5 or 7 bar that is really using it? ahha

Thanks!

Much appreciated. :)

5 bar here but...

I'm running it only to 30 psi since i got a stock motor it should be enough data to setup the limit of the sensor with that amount of boost. Sensor is linear so most of the data points that need adjustment are in the lower range where the highest VE gradients are.

Adjustments are very easy if you think the load isn't high enough because you need more fuel you just set the load higher for the boost level. Pretty straightforward.

You are also welcome to the rom I've setup for the 5 bar sensor.

Hey Roadspike, it's been killing me, do I actually know you away from evom?

Could be you have any church affiliations thats where i'd say i'm best "known" is in the christian community. I'm not really a car scene guy :lol:

Edit:
Looking up hayward its seems unlikely we know eachother unless you work for CBSi like i do and happen to have met me in the networking infastruture team move of my own parent company. :)

haha nope, I was wondering if you used to post on NCE or currently on Evo Empire?

Never heard of those places to be honest :)

I guess my style isn't unique as I had dreamed it was if I have a mistaken identity here :lol:

never heard of Norcalevo?

Only reason I asked is because it says you are in Sac. :)

Ooh so that's what NCE means yeah I've read the forums but never registered there ever.

haha ok, just curious, NCE is dead now anywho.

Back to our regularly scheduled programming....

Thought I'd post some pics so people can see not only my shoddy ass welding skillz but what happened to the engine bay in light of speed density.

very cool, looks good.

Im doing the conversion to SD pretty soon and I'll be using a AEM 5 bar map sensor. Can I get a copy of that rom? Thanks

Wow,

I'm really interested in seeing what Mellon can get out of the MAF-T, and eventually SD. I wonder if either of these would make much on stock frame turbos.

"stock frame" could be anything from stock turbo to HTA Green or Red and with race gas and high boost, I'm going to yes, it could help.

Sure if you want the current one send me a pm with email if you want to wait a couple days while i iron out the low load spots you can get that version.

Well starting to notice a pretty unique trend in my tweaking. The low load is really much more VE efficient than i believed. It seems I'll be putting in values over 100% from 1500-3500rpm where i got a lean spot forming in the middest of seemingly perfect 14.7 deviation.

Starting to wonder if the cause of this lean spot is due to the cams I'm using.

Well got still some minor deviations from perfect 14.7 which I think may be attributed to ignition timing so i'm going to try lowering those points a bit. All and all its nothing the O2 sensor couldn't take care of. Only real rich spot is just before load reaches 0 around 10 or so.

I also think the car runs slightly richer when its cold out which is weird but may have something to do with a table i'm not adjusting.

Not that I'm an expert, but isn't that one of the inherent flaws with SD?

+1...I've read in the past that the biggest drawback is outside temperature change affecting the tune

I had the same problem with the maf-t back in the day...the fixed IAT temp of 80* meant the ecu didn't compensate for weather changes. SD should have an IAT sensor though.

how big of a AFR drift are we talking about between a cold morning and hot afternoon. I used to see mid 10's afr to 12's, completely unacceptable so I ditched the maf-t

its only a problem if you do not have temp compensation tuned correctly. If you don't, it can be anywhere from a nagging issue when the weather gets hot to a really big problem when the weather gets cold.

Not much maybe half a point on average.

It might be cheating but.... I was thinking over the weekend.... we have all the scaling tables for the stock maf, so what is the limit choke because the diameter of the tube the maf if is in, why not just log the of the maf and fuel trims, and build a bigger housing for the maf, log and correct the scalings in the maf to get the fuel trims back inline, similar to how you rescale the MAF for new filters etc.

Im not sure if its possible.....or worth while with SD, but it is still using the "stock maf" just in a bigger pipe... just a thought...

Another Idea I had was because the 8/9 maf is sort of one plastic piece, and to get the sensor part out, it seems that it would have to hacked apart considerably, maybe we could the maf out of a X because it is bolt in.... and put it in a bigger pipe and rescale.... That would for sure be cheating, but it is "A" "stock MAF hahaha.....

Just throwing out ideas.....

I want to know more about this table I did a run today cruising around town this afternoon where average temps were about 100F instead of 80F this morning and found the tune was spot on again. If there is a table i can adjust the amount of fuel that the car throws at it due to air temps that would be great.

I'm assuming the table is called air temperature compensation but i have no idea what the units represent.

ygpm{thumbup}

There's a pretty exhaustive thread about this. Long story short: generally not worth it.

I cant help but wonder, maybe its not worth it for the average guy, but some one that is likely at the choke point and doesn't want to go SD.... it might be worth it.

Thanks for the Info, Ill look for that thread!

Why not toss in a Z06 MAF? They are 3.5 Inches in Diameter and can easilly flow over 1000WHP.

I have a FullThrottle MAF-T setup with the GM MAF, when I lived in SE texas with the mods in my sig I got 525HP 486TQ on the stock block, stock head, stock turbo 98pump 100% meth 28 PSI ( yes I know I am over running the stock turbo :) ) on a dynapack.

When I lived there in the summer it was 105 deg 100% humidity heat index 115 deg / winter 30-40 deg rare snow a lot of ice elevation 20 feet below sea level. So I had 2 setups on my ECU map and MAF translator one winter and one summer.

In CA on 91oct I am getting 487HP 442TQ same setup new conditions. 20-60% humidity 95 deg summer and 60 deg winter. I now have one ecu and translator map for all seasons but I gained some numbers back on the ECU because it took less MID and HIGH settings on the translator to get my AFR's and timing where I liked them on the lower oct. gas. I think the lower humidity and my elevation is now 500-2000 ft above sea level is where this gain came from.

When I say gain I was getting the the edge of the cells 19.4 because of the effect of the translator on the ECU. Now I am back down into the 10-12 range on some cells that were 17-19 before.

The ONLY reason I used the MAF-T is I had the same setup on my Eclipse so I had some idea of what I was doing.

On my other evo I am about to try out SD so ill have a MAF-T vs SD setup at my hands. I have never been a stock MAF guy. I always question what conditions = the stock MAF limit as its just as prone to atmospheric conditions as the MAF-T setup IMO but you know the limit of the GM MAF when you start. So your all ready 1 step ahead of questionable anomalies of the "what is my stock MAF limit?"

the MAF-T sends a fixed temp to the ECU, that's my beef with it. The stock ecu sends the actual ambient temp so the ecu can make minor adjustments to keep the AFR where you left it.

Can you run a IAT sensor in combination with it instead?

I think the MAF-PRO addresses that issue but it's much more expensive

Two things caught my eye....is that a world record for WHP on the stock turbo???? And 98 octane pump?

hahha +1 saw that too and did a double take!

Is it? I never really paid much attion to that stuff, I just wanted to see if I could break 500 on it so I setup everything with that goal in mind.

With this setup I clean up on Stock GTR's all day. There are about 4 GTR's in my area and I have whipped on strightline and in the canyons.

Its all in the meth {thumbup} HEET FTW!!

Anyways back on topic, I like my GG GSR MAF-T setup but cant wait to get into the SD stuff on my TB SE. In the end I think I am going to like SD more.

Not to be negative, but that boost level on a stock bottom end/head does not equal 525 on a dynojet. I can reliably say I know exactly where the end of the stock turbo is and it requires far more than the mods you have listed.

I am just going by what the dyno said if I still had the printout id post it. I am not trying to prove anything here with my HP, just wanted to give my .02 on my maf-t setup thats all {thumbup}

Cool..

re-MAFT

MAFT Pro is only 399 plus sensors but it still has some of the bad habits the translator does. Even though you can use barometric correction and wire the IAT, it still has quirks that stock ECU speed density doesnt. There are tricks you can do with the Translator to make it work better, but as has been frequently pointed out its just not as cool as it seems.

Really though if your curve is dialed in the software, you can just use the Translator after that to make changes throughout the year as needed. The base adj, and the 4 trim adj go a long way in making it all happy.

No way {thumbdwn}

ahhh a fresh glass of hater-aid. Nothing better on a hot summer day :lol:


Does anyone know if you can use an ext. IAT on the MAFT Gen 2 setup? Trough the AUX or something?

^^^ Please post a graph :) ... It does sound to good to be true, especially on meth maybe on a 100% water. No one here has had the the balls to test that but one lol and it didnt last long on a mustang dyno. So not calling BS just a little more info...

Respectfully,

Evan Smith

Well posting up my copy of speed density with all mods on e85.

I'll post up a copy with boost control added later right now the scalings are off and its not working like expected.

The full rom is posted along with the xml files so you can do a direct copy if you so please. I used 7zip to compress the rom enough so you'll need that or winrar to open up the file.

EDIT:
Updated the SD patched rom i have

Is that ROM set up for the 5 bar MAP? If not what is it set up for? Thanks

yep 5 bar 1200cc injectors basically whats in my sig.

Awesome Thanks alot man. It might be a couple of weeks before I can give it a shot but I plan on it before it gets could here.

deleted. Answered my own Qs with a couple hours of reading.

I've noticed now that the temperature has dropped a bit below 50F that the cold start on this rom was a bit screwed up. I did a test by rescaling the rom with 0-60 load back to normal so I'm going to post that one up soon. Seems there are a couple tables that really need the 0-60load columns to remain the same for cold start driving purposes.

OHHHH I am so excited now. You may finlly find the cure to the cold start idle issues. You Sir, are amongst the Gods.

Its always best to keep the 0-60 load and 0-3500 RPM range as the stock scaling for driveability.

Definitely agreed i had originally scaled it 0,40 and so on thinking the 10-30 loads were redundant. However now it seems they not only effect idle but I've found that cold starting and cold running take off from a stop are much improved.

Just like MrFred I've found i had to add some decay time to the cold start to ensure it doesn't drop lean until the o2 sensor kicks on.

When I was running SD, I never had any cold start issues that I remember and still don't have any with my new 1250s, but I'm not on SD anymore. I do have all stock scaling for now as well.

I'm curious about your 'dropping lean' comment, though. You were going lean at idle? If your injector scaling and latency is set correctly and your two VE tables are set correctly, the idle should be good.

On second thought, you are probably talking about the atomization difficulties of E85 at lower temperatures, so the need for more fueling for a longer time, until things warm up.

Well I run E85 so it may just be a product of that but I've noticed when the air temp is below 50F it would start fine then sorta stumble lean then correct itself to running right.

Seems most of the issues were simply how the load in the low range was scaled.

why did you get away from SD?

There was a weird IPW oscillation that I was experiencing only in a very specific RPM and map range.

Here is page 4 of the thread where I was testing and found the issue. I have posted and discussed it from that page on, but never found the exact cause.

All in all, it's not that big of a deal, but I would rather have it solved before I run SD full time, since this is my only car. I may still switch over anyway, since I have a 4" intake pipe and filter that I have been waiting to put on. But, I wanted someone to look over the code again to see if they see something that may be causing it.

can you elaborate?

Edited my post with a link to the thread that discusses it.

Well to conclude the 0-60 load test the difference is seriously night and day!

I certainly recommend any tuner not change the 0-60 load columns when making a map for low load drivability. Cold starts and running is very smooth now where it was a fussy before. There is still a little bit of messy acceleration on cold starts but it seems to be limited to higher load than 60 probably more like 80-90 load. I'd bet if i put in the stock loads 0-100 it would be fine but i can live with peddling it when cold to have better resolution for high load.

I wonder how effective it would be to cut the thing apart and make a larger diameter one. You can even use stainless steel honeycomb in front for a smooth air signal back to the ecu like the stock one.:) If the sensors and circuitry are the same for other mits vehicles you can easily get a small MAF at a junk yard.

Interesting read. I've been contemplating the sd patch as well, but the cold weather thing has been bothering me. We get alot of weather changes here in alaska.

I've been wanting to transplant the guts of my stock mas into a larger pipe and try that myself but don't have a spare. Somebody said they didn't have luck with it but that doesn't discourage me, I might know something about dialing the tune in that they missed.

update for those who missed it, I'm now at 790awhp 706tq at 46psi through the stock ecu/maf which is right at the maximum anyone has ever done on the HTA86 turbo. It's more clean that ever that the stock maf doesn't pose a substation restriction.

So what was the issue you were seeing that made you suspect you were at the limits of the MAF?

I'm really not sure...on the old 9:1 motor and HTA86 it was making about 700awhp at 38psi and 45psi only about 10awhp more but the tq was going way up. Now I'm on a 10:1 motor and my timing is less aggressive but it's making way more power at 45psi. I have to wonder if I just went too far with the timing map back then. I've definitely changed my strategy since then.

That is quite the accomplishment 790awh on stock maf, wow! Doesn't surprise me that the Mellon Racing name is attached. Once again, you've really outdone yourself. I can't wait to see what you come up with next.

thanks, we just wrapped up the pump and c16 tune on gary's stock ecu/maf smaller 3582 turbo. 600awhp on pump at 30psi and 736awhp on c16 at 42psi. Again the stock maf doesn't seem to be holding us up. https://www.evolutionm.net/forums/ev...-pump-c16.html