Low Airflow #s... KEEP IT CIVIL OR MOVE ON.

[g34rh34d]

Did some rough tuning on my car.. I was flowing 41lbs a min last night which to me is good from an evo3 16g on a tired motor... Anyways.. here are some logs, Tell me what i should change to make it snappier...

Mods:
6bolt
255 pump
aeromotive FPR base pressure of 43psi
boost controller at 22psi
PTE 680CC injectors
Large FMIC
greddy bov
Fuel pressure gauge showing good rising pressure under boost
NO wideband yet :(

logs below if they show up...

http://www.dsmlink.com/forums/attachment.php?attachmentid=12527&d=1187479762

http://www.dsmlink.com/forums/attachment.php?attachmentid=12528&d=1187479856

Thought I would start a new thread vs. hijacking the other thread...

This arises my concerns about my car.. :confused: When Steve and I went out last week and tuned my car, no matter what boost I had set at from about 18 lbs on up to 22, I was only showing ~ 25-27 lbs/ min of airflow. Explains my inability to get more than about 265 hp (corrected) at the dyno. Ironically this is the same problem I had with my SM 16G. I then upgraded to an EVOIII 16G, assuming that the SM 16G couldn't get me decent airflow #s and still I have the same flow issues.. Odd. Could the difference between a 6 bolt and 7 bolt be that much??

Mods:
Stock 7 bolt block and head / cams. (Should I suspect the head??)
Stock Mas
EVOIII 16G
Profec B set at 22lbs
K&N
ETS FMIC
Greddy BOV
RC 550s
Walbro 255
3" exhaust w/ High flow Cat.

Thoughts?

FH

[D Walker]

Posted my thoughts int the other thread, but forgot one other thing- How old is your cat and is it a mettalic element cat or a ceramic element cat? If its a ceramic element cat it can be melted already and quite a restriction

[thiazole]

I'm just going to ignore all the other stuff the other thread has become and stick to the topic. According to http://www.turbobygarrett.com/turbobygarrett/tech_center/turbo_tech103.html

"For example, a reading of 12 psig on a boost gauge means that the air pressure in the manifold is 12 psi above atmospheric pressure."

If that is true, then the math I used above is still correct. Also, I need my compressor map that I've drawn on in front of me, but if I'm not mistaken, it predicted around 38lbs/min at 30psi gauge presure at this elevation. And if you know me, you can be sure I crossed all my t's and dotted my i's math wise. My engine has a stock cam. I'm not getting into the argument of whether AWDER's engine really flowed what was claimed or not, but saying that it seems possible by my math.

[D Walker]

I'm just going to ignore all the other stuff the other thread has become and stick to the topic. According to http://www.turbobygarrett.com/turbobygarrett/tech_center/turbo_tech103.html

"For example, a reading of 12 psig on a boost gauge means that the air pressure in the manifold is 12 psi above atmospheric pressure."

If that is true, then the math I used above is still correct. Also, I need my compressor map that I've drawn on in front of me, but if I'm not mistaken, it predicted around 38lbs/min at 30psi gauge presure at this elevation. And if you know me, you can be sure I crossed all my t's and dotted my i's math wise. My engine has a stock cam. I'm not getting into the argument of whether AWDER's engine really flowed what was claimed or not, but saying that it seems possible by my math.


Should really start a new thread, but:

I do not believe that for one second based on the data I have. Every single boost gauge we have used(and I have used them all) have been different from the MAP sensor by the exact amount of atmospheric pressure. Not in a single case, but in every single one on multiple cars. Until I have a better explanation, I do not rely on boost gauges for anything other than to know the turbo is working, to quantify changes up or down, and to indicate problems. If a MAP sensor and its data is available, I use that to quote boost numbers- as an example(but by no means gospel) on my car I ran 24psi as indicated by the MAP sensor, which if I had had a boost gauge would have been 26-ish psi.

It becomes then very useful to know HOW the boost level is being determined- 26 psi is a big difference than 26psi, and depending on what language you choose to use can mean very different things.

I have complete faith in your math, just that the numbers you are plugging in can be skewed.

[XakEp]

Not in a single case, but in every single one on multiple cars.

What is this supposed to mean?

[D Walker]

Ahh- I guess that it means that if it hade been a single car or ECU that had done this then it could be attributed to that specific car, turbo, ecu, manifold design, whatever, but since it occurs on multiple cars I tend to believe that data.

[thiazole]

That's good enough for me. The only way to prove one way or another is with some dyno numbers or something like that to back up the claims.

As far as the original topic, as stated before:

1. Check your BOV - if it is seriously leaking back into the intake.
2. Look for restrictive intake tubing, especially where you make turns "out of view". I'm not sure what your intake tubing looks like, but I had a minor kink in a rubber turn that was really hard to see unless I was underneath the car. When I fixed that, it made a significant difference.
3. Something I didn't think about until now, but your boost gauge might be WAY off. One way to test it is to get a big syringe (go to your local drug store first thing in the morning - don't shower - wear dirty sweats and shake a little while purchasing - and buy the biggest syringe they have - preferably 50cc). Open the syringe to the highest number on it (ie 50cc) and attach the opening of the syringe with a SHORT rubber hose to the boost gauge and compress it 2X (ie to 25cc in this example) and 3x (ie to 50/3 = about 17cc) and watch what the gauge does. In theory, it should show about 12-13psi at 2X and 24-26psi at 3x. If it is way low, then you just aren't boosting at the pressure you think you are and that is probably your problem.

[Wazzelby]

Thought I would start a new thread vs. hijacking the other thread...

This arises my concerns about my car.. :confused: When Steve and I went out last week and tuned my car, no matter what boost I had set at from about 18 lbs on up to 22, I was only showing ~ 25-27 lbs/ min of airflow. Explains my inability to get more than about 265 hp (corrected) at the dyno. Ironically this is the same problem I had with my SM 16G. I then upgraded to an EVOIII 16G, assuming that the SM 16G couldn't get me decent airflow #s and still I have the same flow issues.. Odd. Could the difference between a 6 bolt and 7 bolt be that much??

Mods:
Stock 7 bolt block and head / cams. (Should I suspect the head??)
Stock Mas
EVOIII 16G
Profec B set at 22lbs
K&N
ETS FMIC
Greddy BOV
RC 550s
Walbro 255
3" exhaust w/ High flow Cat.

Thoughts?

FH

My thoughts on this are that you really aren't far off from where you should be. You are using a stock head with stock cams and a 2G intake manifold. None of those items flow very well up top where bigger turbo's make thier power. The EvoIII 16G is not a big turbo by any means. so somewhere in the low 30's for pounds per minute is about right. Yes, a 6 bolt will flow better (at least the head and intake manifold from a 1G) but nothing as drastic as you would think.
Now, if you are below 30 pounds per minute and aren't seeing it rise with more boost, I would suspect one of the following:
Boost leak
wastegate blowing open
leaky BOV (which falls under boost leak)
and high flow cat....
I know I'm going to get flamed for this but I took off my high flow cat the other day and with no other tuning I went from 35 pounds per minute at 21 PSI to 39 pounds per minute still at 21 PSI... Granted I saw 21 PSI a few hundred RPM sooner and that may have contributed to more PPM because it created more flow closer to where the engine is running at 100% VE, but that's just a guess..

[Cloud]

Personally that seems like a complicated and innacurate way to test the gauge.. I always use my air compressor.. I regulate the pressure to 20psi and then hook the line to my boost gauge.

And you know the gauge on your air compressor is accurate to within +- 1psi or less how? Boost gauges, MAFs, and all the things you would really like to get good data on in a car are almost ALL very inaccurate and just calibrated from the factory to work with each other acceptably.

[thiazole]

Why would that be inaccurate? As long as it doesn't leak and you allow the temp of the compressed air to equilibrate, it is probably the most scientifically accurate way to test pressure for those of us that don't have complicated mercury setups. I've done this before and it works perfectly.

[thiazole]

BTW, I've seen cases where other people have changed gauges and had completely different results with the new gauge. Doesn't happen very often, but does happen.

[XakEp]

I know I'm going to get flamed for this but I took off my high flow cat the other day and with no other tuning I went from 35 pounds per minute at 21 PSI to 39 pounds per minute still at 21 PSI... Granted I saw 21 PSI a few hundred RPM sooner and that may have contributed to more PPM because it created more flow closer to where the engine is running at 100% VE, but that's just a guess..

There's no reason why you'd get flamed for this - its pretty much true.

[Wazzelby]

There's no reason why you'd get flamed for this - its pretty much true.

You know, I figured I'd get the whole "there's no way you got that much more airflow" etc. etc.. Just making a point about his cat and possible boost leaks.

[thiazole]

It is especially likely to make a huge difference with a turbo like yours where you need as much exhaust flow as possible to spool that monster. I'm eager to see how your car runs now! You're getting there. I've seen a few people that mentioned that it took a couple years of trying different things before they got turbos like that to run right. You're on the right track.

[Rigbender]

When Steve and I went out last week and tuned my car, no matter what boost I had set at from about 18 lbs on up to 22, I was only showing ~ 25-27 lbs/ min of airflow. Explains my inability to get more than about 265 hp (corrected) at the dyno. Ironically this is the same problem I had with my SM 16G. I then upgraded to an EVOIII 16G, assuming that the SM 16G couldn't get me decent airflow #s and still I have the same flow issues.. Odd. Could the difference between a 6 bolt and 7 bolt be that much??

Mods:
Stock 7 bolt block and head / cams. (Should I suspect the head??)
Stock Mas
EVOIII 16G
Profec B set at 22lbs
K&N
ETS FMIC
Greddy BOV
RC 550s
Walbro 255
3" exhaust w/ High flow Cat.

Thoughts?

FH


What are you using for tuning for the larger injectors? I don't see anything on your list. As far as I know, a stock ecu can't run 550's without issues. Might that be an issue? I agree with Wazzleby on that you are close to where you should be. Going from a stock mas to larger turbo, then larger fmic, and back to stock sized intake and head is gonna cause a flow restriction in there somewhere. As for the difference between 6 bolt and 7 bolt, I don't think it's as big an issue, flow-wise, as it seems.

(Also, mods, can you bring this one back on topic also? Had to read through way too much stuff that has absolutely nothing to do with the thread topic.)

[thiazole]

(Also, mods, can you bring this one back on topic also? Had to read through way too much stuff that has absolutely nothing to do with the thread topic.)

Then the mods should shut down all the threads, because they all get off topic eventually. The last thread was shut down because it was out of control, not because it was off topic. If moderators become oppressive here and start shutting down every thread because it goes off on a tangent, then it will ruin the board and people won't want to post anymore. I don't think that is what we want.

Several suggestions have been made that are on topic and so far we haven't heard back from the original poster, so the purpose has been fulfilled.

[g34rh34d]

Then the mods should shut down all the threads, because they all get off topic eventually. The last thread was shut down because it was out of control, not because it was off topic. If moderators become oppressive here and start shutting down every thread because it goes off on a tangent, then it will ruin the board and people won't want to post anymore. I don't think that is what we want.

Several suggestions have been made that are on topic and so far we haven't heard back from the original poster, so the purpose has been fulfilled.

WOW!!! :confused:

OK First of all my apologies to Steve and those who have posted some valuable information for me to check into.

I really didn't write the original thread with the intention of things to get it out of control as they have.. Nor was I trying to invalidate in any way the things Steve has done to help tune my car. He is in my opinion very knowledgeable in what he has shown me in tuning and my talks with him. I truly am indebted to him for helping me on very short notice, and amongst our very busy schedules.

Nuff said .. now back on topic... I will try to answer some of the questions or suggestions as I have read them.

In reference to the tuning tool I failed to mention we were tuning on DSMlink.

I have performed many intake leak checks to verify my boost gauge. it is accurate +/- 1 psi based upon the granularity of the gauge itself as compared to my gauge on my air compressor regulator.

When I was running my sm 16G as well as when I first put my EVO16G on, I did have a pretty large intake leak in the core of my old Alamo SMIC. (which I was also logging the same airflo #s plus or minus 1 or 2. I remedied that issue with the new FMIC and piping, and performed leak tests on the new setup. So far it has held. But I do plan on doing another to see when my BOV is opening.

Injectors - RC 550s. We were seeing somewhere between 70-80% injector duty on the WOT pulls.

BOV - I do have it adjusted to a very light setting, due to some off throttle compressor surge I was experiencing. I might just need to adjust it again.

Exhaust - Very possibly the real issue.. I do have a "High flow cat" installed by Buds Muffler, when they did the 3" setup for me. Yes there is a very short (~ 2") section of 2.5 pipe right at the manifold and before the j bend. I need to fab up a test pipe and see if that nets me any real gains.

Manifold - I have ported the Exhaust manifold (port matched to the EVO 16G.)

Boost controler - Greddy Profec B. Maxed at 22 psi. I might need to put my old MBC back on to surpass the 22 psi threshold, and see if that is the problem.


Expectations - I definitely wasn't expecting my EVO16G to net me huge #s, I was expecting to see my airflow #s increase as compared to my old logs. just by virtue of fixing the intake leak I had in the core of my old Alamo SMIC. In reality, I was hoping to see #s somewhere in the 30-32 Lbs / min by running 20-22 lbs of boost. Possibly unrealistic for that turbo. I'm not sure. I just wanted to see some improvement. and I haven't, which is why I posted the thread initially.

I will try to attach a couple logs of the runs I made after Steve and I went tuning. One of the logs is a single 3rd gear pull at 22 psi, the other is a 1-3 gear pull. (They didn't post when I uploaded them in this message.)

Finally, Sorry for the late responses to posts, I'm on company travel right now and haven't had alot of time to get on line to check the forums. Thanks again to all of those who have posted some good info!

FH

[thiazole]

I was just pointing out that when you have so many different people posting, there are going to be disagreements. If someone said "hey, you need to put more air in your tires - that'll improve engine flow", we don't want forum rules that won't allow us to challenge that person because that would be "off topic".

30-32lbs/min is a very realistic goal and when we figure out what is going on, I think you will be able to get better numbers. I wasn't saying that Steven was at fault for those low numbers and I agree with others who have said he is a DSMLink master. There is something physically wrong causing your problems. I think I was getting 26lbs/min with my T25.

Exhaust: I don't think a little 2 1/2 inch exhaust is going to kill your airflow. It isn't ideal (and it disrupts the flow of the rest of your system), but many people have gone 12s or better with a full 2 1/2 inch exhaust system.

Boost Controller: Definitely try a manual boost controller to rule that out.

Another thing: Did anyone mention the possibility of wastegate problems? You might want to make sure your wastegate is closed in the position that your actuator is at rest. Having a wastegate that is partially open all the time would kill your boost. Make sure the actuator itself has tension - it should be very hard for you to move the arm by hand.

[D Walker]

There is no way the boost controller is the issue if it is properly setup and functioning. Your actuator might be a little "soft" and/or need adjustment, but any EBC should hold whatever boost the turbo will make.

Exhaust restrictions are the single largest contributor to a turbo not making the boost it "should", so it would really help to know what type cat you have. Ceramic cats have a very high failure rate on turbo cars due to the exessively rich mixtures we run.

The Greddy BOV might be the issue. We have had far greater success with the HKS or newer Synapse units.

Verifying your boost gauge against a compressor is OK I guess, but not really what we we are concerned with since you are comparing gauge pressure to gauge pressure.

I assume your tuning the DSMlink based on a stock MAF. If you are, thats good because you are working with relatively accurate data. However, if you are using the GM MAF or for some reason you have locked the IAT, then your airflow readings will never be consistent or accurate, since IAT is needed to calculate density, which is what gives you the lb/min numbers. On a hot day with the IAT locked you will show significantly higher numbers than the exact same car with the IAT functional, since all density calculations will be based off 77 degrees rather than the 100deg which is the true air temp.

[thiazole]

Some people have had trouble with their Profec B, but I'll admit I've never used one.

[Wazzelby]

I have a profec B and I cannot ge tthe boost above 25 PSI. I have to use a manual boost controller when I go to the track if I want to raise the boost. Electronic boost controllers usually only go "X" amount over the wastegate pressure.

[XakEp]

I have a profec B and I cannot ge tthe boost above 25 PSI. I have to use a manual boost controller when I go to the track if I want to raise the boost. Electronic boost controllers usually only go "X" amount over the wastegate pressure.

I can second this information. My E-boost manual says almost exactly the same thing about the wastegate spring.

[Mr. Moose]

If the question involves the practical limitations of a Evo III 16G, I can simply observe that on the right car, with the right combination of parts, the Evo III 16G has put down 452hp and 434 torque at 28 PSI using E85 (at sea level). Using a very general rule of thumb of 10 lbs/hp., that would be about 45 lbs/minute of flow.

There are other similar Evo 16G cars to the one I used as an example. The issue is the rest of the parts on which the Evo 16G is installed...

[g34rh34d]

Good stuff...

Yes, my setup is using the stock MAS, so the #s should be more accurate.

I really dont think the 2.5" Exhaust piping section is as much of an issue as the possibility of the Cat being the restriction. I will definitely have to do something there.

As far as the wastegate, I have never checked that. Good point, I will need to see how mine feels when I get back home. It would be awesome if it was something simple like that!!

As far as my goals are concerned, I was hoping to better my dyno pulls (corrected) of 265 hp 299tq. I was thinking realistically that I could get somewhere in the 300-320 range corrected. At the track, my car (with me behind the wheels) has never bettered a 14.36 @ 96.11. the next best was a 14.39, so my hopes were to get into the mid 13s. Again, thinking these were all do-able with my setup. Anything above these goals would be a bonus!

Thanks

FH

[g34rh34d]

I will try to attach a couple logs of the runs I made after Steve and I went tuning. One of the logs is a single 3rd gear pull at 22 psi, the other is a 1-3 gear pull. (They didn't post when I uploaded them in this message.)

FH


Ok, I have tried to attach 2 DSMLink log files, but it seems the file format is being kicked back. so Im not sure how to get the logs up for people to view them.

Suggestions?

[Paul]

Suggestions?

Hi Frank!

First if you want 13's you got to drive it like you want 13's. You didn't post what your 60' time was? I'm not sure what 2 mph is worth, but I ran a 13.7 at 98 mph. I remember the first time I got a sub two second 60' time I was more proud of that than the et.

-I checked your timeslip - 1.95. I assume you have the stutterbox working with DSMLink? When I did my run they didn't have the no lift to shift option yet. Do you have this installed?

If I were you (and of course this is what I did) I would put in some HKS 264 or equivalent cams. If you remember when that was done on my car airflow improved over the whole useable rpm band. Under 300 hp I wouldn't worry too much about a 2.5" exhaust restriction. The airflow restiction hurting you most is where the valves go up and down.:)

Get a test pipe. Cheap, easy, and just like Ryan said worth a couple pounds of airflow.

Then go to Bandimere and take your helmet.:D

Paul

[thiazole]

When you get it running right, you'll be able to baby it and still run 13s, IMO.

[thiazole]

I can't download them for some reason. It might just be this computer though.

[thiazole]

I just installed it. I'd never tried it on this computer before, so I don't know if it is the file or just me.

[thiazole]

I just tried some logs on the DSMLink forum and it worked fine. When I click on your link, I just get a dead page. When I try a save target as, I get an error that says "internet explorer was not able to open the website" or something like that.

[g34rh34d]

After looking at your log it seems your boost est is off.. You said you are running 22psi and boost est shows 15-16psi

Hmmm Odd. I dont know how dsmlink works as far as the indicated boost logs are, but my gauge was definitely at 22 psi. The profec B high boost was turned up to the max.

Should the indicated boost #s match my Gauge? or is there some sort of conversion?

FH

[XakEp]

Hmmm Odd. I dont know how dsmlink works as far as the indicated boost logs are, but my gauge was definitely at 22 psi. The profec B high boost was turned up to the max.

Should the indicated boost #s match my Gauge? or is there some sort of conversion?

FH

oy veh

BoostEst is based on what your ECU sees, not what is actually going into the car. Are you using a GMMAFT? If so, you'll need to calibrate it. If its that badly off you will run rich, your trims will be WAY off and you wont make as much power as you could, not to mention ****ty gas mileage.

http://www.jeffgst.com/gmafcalibration1.html
http://www.jeffgst.com/gmafcalibration2.html

Follow those steps, you'll have a better running car for it. These are the "secrets" that tuning guys use. :rolleyes: If the logged value and BoostEst dont line up, you need to recalibrate it. Period.

[biglady112]

Just so everyone knows, Frank is using a 2G MAS. The tune was stable and consistent from slider to slider. I just think the boost needs to be turned up.

He said from his own mouth, the car has never been this fast. I think we are blowing it out of proportion until he gets it on the dyno or down the track.

To be honest, his guage may very well be a little off, it was quick, but probably a high 13 second car for now. Just too heavy and too low a boost to do some damage. Car is safe and consistent and that is what counts until he installs more stuff.

He is only going to get larger injectors, possibly a wideband and maybe switch to E85. That is all he had planned for the car when we talked.

Steven

[D Walker]

If the airflow calibration is off, the car isnt tuned. Period.

[XakEp]

If boostest is off, you'll need to figure out why and correct it. Its a symptom of a larger problem, esp if he's using a 2g mas and not a GM MAFT. Unreliable boost guages are why I got rid of mine and just log an AEM 3.5 bar MAP sensor right into DSMlink. Makes it much easier to tune.

[biglady112]

There was nothing to question an error at the time. Everything was in line when the we were playing with the car. I expressed my thoughts on a loggable boost source though. After using one for the past two years, I am not sure I could live without one.

If Frank wants to proceed, then I am glad to help. I think we need to see the logs and put our heads together. Ryan's link still does not work.

Oh, and the boostest is only going to be accurate from 5000-5500rpm. That is where the VE should be spot on. He has an entirely stock 7 bolt. So I would assume his car should be just like all the other stockish dsmlink cars.

Steven

[XakEp]

A loggable boost source is a GOOD idea, agreed.

[g34rh34d]

Just so everyone knows, Frank is using a 2G MAS. The tune was stable and consistent from slider to slider. I just think the boost needs to be turned up.

He said from his own mouth, the car has never been this fast. I think we are blowing it out of proportion until he gets it on the dyno or down the track.

To be honest, his guage may very well be a little off, it was quick, but probably a high 13 second car for now. Just too heavy and too low a boost to do some damage. Car is safe and consistent and that is what counts until he installs more stuff.

He is only going to get larger injectors, possibly a wideband and maybe switch to E85. That is all he had planned for the car when we talked.

Steven

Yes true, thanks Steve.

Ok - my goal is to have a streetable 300-ish hp (to the wheels) car. Obviously that would probably be corrected HP #s with the turbo and setup. More would be better, but I'm trying to be realistic.

I do have plans on maybe getting larger injectors. (Btw, would the 880s I see up for sale get the job done? or would 950s be the better way to go?) For now I need to be dollar wise.. ;)

As far as immediate parts go, my eye is set on the AEM UEGO wideband. I think that will serve any future tuning sessions better than the injectors at the moment.

My other immediate plan is to try doing a test pipe and eliminating the Cat to see if I can get some better flow out of the exhaust. And check the wastegate.

FH

[g34rh34d]

If the airflow calibration is off, the car isnt tuned. Period.

At the risk of looking (sounding) more ignorant than I have thus far... How is this done? I currently am using the stock mas, unmodified. What adjustments are made?

[D Walker]

I will try and post a detailed explanation in the morning.

[XakEp]

At the risk of looking (sounding) more ignorant than I have thus far... How is this done? I currently am using the stock mas, unmodified. What adjustments are made?

You fiddle with your airflow sliders in DSMlink until your trims and boostest line up. You will need a WB and loggable boost source to do it right.

[Paul]

I do have plans on maybe getting larger injectors. (Btw, would the 880s I see up for sale get the job done? or would 950s be the better way to go?) For now I need to be dollar wise.. ;)

Injectors - RC 550s. We were seeing somewhere between 70-80% injector duty on the WOT pulls.





Remember Carl ran 12's with 550's. Of course they were ND's. I don't understand the big injector push unless it is similiar to need for bigger gun? ND 660's will do the job for sure. If you are only at 80% what is the problem? If it were me I would send them out to see how balanced they are. Maybe someone does it locally now?

300 hp at the wheels will take higher boost levels than you are talking about. That hp will get you into the 12's.

Just make sure your fuel trims are within reason.

Get cams instead of WB if the budget is short.

I flowed 30 lbs with an FP Big 28.

Take the spare tire out (a little OG humor here).

Paul

[XakEp]

If your boostest is off, your IDC values are artificially inflated as well.