3.25 Maf flash Questions and Impressions

[Darksun280]

I've been driving around on the flash since friday and have noticed some things and I know my car is WAY out the stock parameters by this point but and see what you think.

First off my set up is a 3.25 ID aluminum maf housing. It has a bend in it as seen here.


So first off on normal shifting out of boost you know just shift from 2nd to 3rd gear the DH will drop to 8.8-9.8's which I know a sensor can't read so it just guessing but the car will bog pretty bad. In the lower gears. Like 1-2 shifts it will almost stumble.

When coasting in a gear the A/F s go down to 8's and 9's then slowly go to 11's till you finally come to a stop. All the time its running rich it wants to slightly buck or stumble till a/fs get in the 11's.

My random back fires from being VTA stock Maf have gone away even though it seems im running all around richer but also my car stock maf never acted this way VTA. When I would coast down in a gear the richest it would get on stock maf was 11's but with the new bigger maf housing and flash I'm dropping to 8's-9's

When cruising on the highway my a/fs jump around from 13.1's - 15.5 it does mainly hold 14.5 though but its always bouncing between then holds 14.5 for a little then goes bouncing again.

How many people have the Maf Flash right now is it just Me and Randy since Ron parted out? Also do you have any driving logs from when Ron had the flash on his car?

Was the Maf flash designed to be a stand alone flash or did you guys intend for it to be a base thing that gets cleaned up once pared with an SB? also did you guys have any requirements on how the maf has to be placed?

I've been thinking maybe the maf being on a bend even though i had them turn it more towards the intake instead of facing a wall bend could have something to do with some of my issues what do you think about that? I think the MS6's have more room in there engine bay because I couldn't mimic Rons set up cause of lack of room


Last question is does the SB have the ability once you have the maf flash to clean up any drive ability issues through tunning. So non WOT cruising, idle stuff?

Any input is appreciated. I know answering questions with out logs is hard for you guys to do but let me know and I'll get some DH ones for ya.

[superskaterxes]

well u def need an air straightener in there because your MAF is on a bend. until u do that and get the flash u cant really say u have a problem one way or the other. the dipping low AFR's when coming to a stop could also be a boost leak (read: not vacuum)

[Darksun280]

Originally Posted by superskaterxes well u def need an air straightener in there because your MAF is on a bend. until u do that and get the flash u cant really say u have a problem one way or the other. the dipping low AFR's when coming to a stop could also be a boost leak (read: not vacuum)

don't need an air straightner I've yet to see a big turbo suby car by cobb, perrin or any of the subys run one and the Maf is as sensitive as ours. Plus ron didn't have any. I believe the maf on a Bend is a plausible culprit though but doesn't the maf read off speed not angle? Thats why it has the cover on eiter side of it cause its going to judge by only what goes through there and how fast all that other space in the pipe is moot. I need to hear form another BIG maf user before blame it or one or the other. As for the boost leak thing I had the system tested up to 22 psi before my car left the shop.

[whoosh@Realtune]

Originally Posted by Darksun280 don't need an air straightner I've yet to see a big turbo suby car by cobb, perrin or any of the subys run one and the Maf is as sensitive as ours. Plus ron didn't have any. I believe the maf on a Bend is a plausible culprit though but doesn't the maf read off speed not angle? Thats why it has the cover on eiter side of it cause its going to judge by only what goes through there and how fast all that other space in the pipe is moot. I need to hear form another BIG maf user before blame it or one or the other. As for the boost leak thing I had the system tested up to 22 psi before my car left the shop.

I don't know if you will get much if any feedback on this
there are some owners in the pipeline like Randy and a few others but no seat time as far as I know

I purposely had the MAF in a straight section of tubing at least 3" before and after the sensor to make sure the reading was consistent
also copied my stock MAF size turbo inlet/SRI configuration with the big 3.25" one since it worked so well
I had no AFR fluctuation and honestly never encountered excessively rich AFR's like you explained.
my car drove like stock on the big MAF

I would blame the bend where your sensor is located for your erratic readings but that is pure speculation

[Darksun280]

Originally Posted by whoosh I don't know if you will get much if any feedback on this there are some owners in the pipeline like Randy and a few others but no seat time as far as I know I purposely had the MAF in a straight section of tubing at least 3" before and after the sensor to make sure the reading was consistent also copied my stock MAF size turbo inlet/SRI configuration with the big 3.25" one since it worked so well I had no AFR fluctuation and honestly never encountered excessively rich AFR's like you explained. my car drove like stock on the big MAF I would blame the bend where your sensor is located for your erratic readings but that is pure speculation

Cool ok well that clears that up.
CPE do you have pics of randys set up since he has the flash. I want to see how you mounted his flange since we have the same size engine bay. Also I want to know if the SB is cable able of cleaning up and drive ability issues I have cause of the maf placment?

[quickspeed6]

Originally Posted by Darksun280 Cool ok well that clears that up. CPE do you have pics of randys set up since he has the flash. I want to see how you mounted his flange since we have the same size engine bay. Also I want to know if the SB is cable able of cleaning up and drive ability issues I have cause of the maf placment?

If you go to the P3 section you can see randys set up. As for the SB clearing things up we have not gotten that far yet with his car.

[quickspeed6]

ok i am the one that is working on randys car and the couple of times that i did drive it i did notice the "stumbling after shift or loss of power after shift" with his as well. I have only taken it on the road a couple of times as we are trying to clear up some other issues with the car.

I didn't take any logs of what was going on though. Once i take it out again then i will take some logs and see where it is coming from so that we might can compair notes. i didn't notice the fuel thing accept for when you first start it up and it i will idle at about 13.6 and then it will slowly start to get to stoich. This will happen cold or hot.

[SneakyP86]

Hell just give Jordan a call phil.He is normally glad to talk to people.

[SSinstaller]

During low load situations(basically anytime your not in boost) the MAF is going to be very sensitive to any airflow irregularities.....That bend could be causing all kinds of airflow issues at the sensor.. I'd be willing to bet that if you log the MAF output you'll see some voltage readings that don't make much sense, because of your MAF placement.

[Darksun280]

Originally Posted by SSinstaller During low load situations(basically anytime your not in boost) the MAF is going to be very sensitive to any airflow irregularities.....That bend could be causing all kinds of airflow issues at the sensor.. I'd be willing to bet that if you log the MAF output you'll see some voltage readings that don't make much sense, because of your MAF placement.

but tooling around in a parking lot and cruising on the highway are two different things but both are low load.. highway at 65mph on cruise is what 13% throttle that should be moving more then enough air to get a steady reading.

If the SB can clean some of these thing sup it would save me the head ache or having a different pipe made. Guess I could move the maf closer to the coupler where it's straighter.

[SSinstaller]

Originally Posted by Darksun280 but tooling around in a parking lot and cruising on the highway are two different things but both are low load.. highway at 65mph on cruise is what 13% throttle that should be moving more then enough air to get a steady reading. If the SB can clean some of these thing sup it would save me the head ache or having a different pipe made. Guess I could move the maf closer to the coupler where it's straighter.

You really need to log the Maf output to see what's going on.. If your on the highway cruising at 65 and the maf voltage isn't very steady you need to move the MAF.. All the standback can do is scale the MAF output up or down, no amount of scaling will fix an airflow problem that causes a false output...

[Darksun280]

Originally Posted by SSinstaller You really need to log the Maf output to see what's going on.. If your on the highway cruising at 65 and the maf voltage isn't very steady you need to move the MAF.. All the standback can do is scale the MAF output up or down, no amount of scaling will fix an airflow problem that causes a false output...

Cool so that answers another one of my questions I guess. I'll do some logs and post them up That will make figuring this all out easier. My cars back at NRG for the DP or dump tube hitting something hopefully I'll have it back tonight

[y2kc0wb0y]

I know there has been a lot of research on this by the cp-e guys......lol; I see them reading this thread.

[dadasracecar]

There will never be a stable value coming from that bend. Because of your space issues, I'd move it way back near the battery and put an air straightener after the bend. The other option may be to replace the bent MAF housing with a straight short ram like the nano or cobb. An HKS filter might be required for space considerations. That MAF may not be the whole problem, but you'll never be able to isolate any additional issues until you get it straightened out.

[www.cp-e.com]

Originally Posted by Darksun280 First off my set up is a 3.25 ID aluminum maf housing. It has a bend in it as seen here.

You really need to put the sensor before any bends. MAF sensors measure air velocity, so any bends or changes in diameter are going to screw with the resulting signal. If you look at the other 3.25" MAF housings posted they all place the sensor before any bends. The Standback cannot tune this problem out, and you'll likely have to put that sensor into another housing that isn't curved.

Phil, when you have issues such as this one you really should give us a call (301-576-6142)!

[Darksun280]

Originally Posted by www.cp-e.com You really need to put the sensor before any bends. MAF sensors measure air velocity, so any bends or changes in diameter are going to screw with the resulting signal. If you look at the other 3.25" MAF housings posted they all place the sensor before any bends. The Standback cannot tune this problem out, and you'll likely have to put that sensor into another housing that isn't curved. Phil, when you have issues such as this one you really should give us a call (301-576-6142)!

Yeah Bend is number one culprit but by posting it I learned alot and I got multiple answers/thoughts. Its just the way I do trouble shooting I look for multiple opinions. Didn't mean to offend you guys and wasn't looking for trouble like I said car under wot is golden I just had little quirks when trying to drive the car like a human being.

I'm going to try adding a screen before the maf then im going to try and have nrg move the maf right before the coupler since thats the straightest piece of pipe im gonna get on this set up.

[superskaterxes]

just for the record,

whenever u have a bend PRE-MAF, you need an air straightener. u would also need one if your MAF was mounted in a bend (which clearly isent good altogether). it should also be mounted in a straight section atleast 3 inches prior to any bend in a pipe

[06Speed6]

Why in the world would NRG mount a maf in a bend, you cant do that on any car I know of. The problem with the bend is that the air flow only uses the outside part of the diameter of the bend which increases the speed of the air in the bend. Since the ECU is assuming a full 3.5" of airflow at that increased flow speed, it is going to be adding extra fuel to match what it thinks is there.

Ideally the maf should be 3" before and after any bends, and since air straighteners and screens dont really cost any power, I would add them in as well.

[ms3guy22]

darksun why do you even have it? besides the obivious or coarse. I mean are you maxing out your maf voltage. even at 20psi on my 3076 i'm not maxing out the voltage

[Darksun280]

Originally Posted by ms3guy22 darksun why do you even have it? besides the obivious or coarse. I mean are you maxing out your maf voltage. even at 20psi on my 3076 i'm not maxing out the voltage

Cause a 60-1 is bigger then a 3076. Think of it like this my 60-1 set up would be like a Gt33r if one ever existed . Id max out between 18-21 and I need minimum 21-23 to even consider 400whp which I considered when I was shopping for a turbo.

It spools faster then a gt35r yet go toe to toe with one power for power.
Its 700-1000 dollars cheaper then the atp 35r turbo
its rebuild able and upgradeable for 250-350

[ms3guy22]

right on

[fbpem1]

i will take one please, don't "need" it now, but will soon =)

it needs to be out there on a car running so yeah gimme gimme gimme =) see how stupid i can go with boost haha

[socks]

I maf-cut at 21psi.

if using meth, can i clamp the maf at 4.85 to prevent the cut, since im adding aux fuel anyways?

[SSinstaller]

Originally Posted by Speed3shon I maf-cut at 21psi. if using meth, can i clamp the maf at 4.85 to prevent the cut, since im adding aux fuel anyways?

Clamping it might be fine for a few days while your waiting for the larger MAF housing and flash, but it's definatly not safe as a long term solution...