maft question

[El Supracabras]

Hi there, im new to the site. I have an 89 targa na/auto swapped to gte/r154 with many upgrades. I recently purchased a gen2 maf translator that came with a delphi 3.5" maf sensor both new for a song. I want to run it in blow-thru. Is using the 3.5" sensor with 2.5" intercooler piping via silicone reducer couplers a good idea? My i/c piping and the sensor are brand new so I'd like to figure out how to keep them. thanks in advance for any suggestions.

[cre]

I'm assuming you're planning on running the 2.5" pipe all the way up to the sensor and then use a coupler?

If you're going to be tuning the fueling (which you really should, even if you're just using the unit for a MAF translator) it'll be fine, if not, you'll need to determine how far off the measured airflow is from actual as you're not going to be flowing as much air through the outer areas as the inner... I had this problem.

You may run 3.5" pipe before the sensor for a foot or so, that'll allow the airflow to even out well prior to going through the MAF's screen.

[El Supracabras]

Thanks cre, I'm glad you answered. You seem to be the final word in many posts and I noticed you run a maft as well.

Correct I was thinking of using 2.5" pipe from the intercooler to the 3.5" sensor, then back down to 2.5 pipe and into the t/b using silcone reducers on the sensor. This seems like a big transition to me and I only ask because I already have these and they are new. If it will negatively affect the performance, well then I guess I have either a 2.5" upper hardpipe or a 3.5" sensor for sale or trade for more useful pieces. Is there even any practical benefit to using such a large sensor (made for a 6.0L!) on car thats goals are under 500HP? Would a 3" sensor would be sufficient? I like the idea of bumping it up a foot before the sensor but I would still need new hardpipe and given the ammount of room in that area might put the sensor pretty close to the hot turbo.

I do plan on tuning the fuel as much as I can to compliment the other upgrades and keep the engine off the stand as long as possible. I do have a wideband and an safc2 (not used for afm,just knock/tps/rpm/looks cool) to watch sensor readings and let me know if im getting into trouble.

I would like to get the most out of the maft setup and make sure the sensor gives smooth and accurate readings. I'm really after the quick throttle response that this set up has a reputation for. Thanks again.

[cre]

Final word... that sounds rather totalitarian...

Yes, I run the MAFT Pro in my car and I've installed and tuned a few for other people as well. If you have any issues with persistent error codes getting set in the ECU look at the link in my sig for some information about it; You'll also find a guide with details about many of the settings you'll find in the menu of the Gen II... there's more than you'll have as it's for the MAFT Pro, but the shared settings are relevant.

So, you're going to be running it like this:


Yeah, you'll need to tune. The cross sectional area is too different and there's not really enough room for the air flow to level out and flow evenly... you get a lot more air running over the hot wire then the surrounding area and as a result you run quite rich. The picture shows a 3.5" MAF and 2.75" intake pipe from my old N/A setup.

It's not a big deal and you're not going to run lean until you fix it... you'll run rich, but that's safe. Connect your wideband to the MAFT Gen II and learn how to tune.

I'd stick with the 3.5" since you have it and it's far less restrictive and you have a wideband with which to tune.

[El Supracabras]

Sorry, totalitarian is not what I was implying, only that your posts tend to be the last in many threads (final word) and are usually very informative. I suppose I could have chosen those words instead. It was meant as a compliment.

Yep, thats how I pictured it. It does't seem like a good idea looking at it and I really dont want to do it that way but I'm a little broke right now and anxious to get the supra out. How well did that set up work for you?

I am going to try and sell some of my extra mk3 goodies to fund a new cold side piping set up. Ideally (I think) I'd like to bump up the 2.5" diameter at the i/c outlet to 2.75" and work up to 3" while going around the core support into the engine comp. and then into 3.5" as long as I can before the sensor. Just not sure if I should reduce it back down before going into the t/b. Does this sound like the right path?

I definitely plan on using the gen 2's wot wideband tracking feature (I read you can even set what tps % the unit will consider wot,cool) maybe even the window switch feature in the future.

Anyway I appreciate the input and the visual, thanks again.

[Green7mgte]

lol. that made me laugh

[cre]

ROFL! Man, I was just screwing with you... yeah... there is an odd pattern of me ending threads by replying to them. I hope it's because I've satisfactorily answered the questions, but sometimes I wonder if it's just because everyone else is fed up.

Anyway. You'll have to forgive me, I'm not completely up on what features the Gen II does have and doesn't have that the Pro does. With WOT tracking you tell the Gen II when it's supposed to start tracking for a given AFR by TPS voltage. This doesn't mean you can have the Gen II take over before the ECU is in open loop itself (~2.70v). If the Gen II has it you can use the ETPS feature to send the ECU a WOT signal so the ECU goes into open loop prematurely. You can set values for TPS voltage or RPM. Gain controls how quickly it raises the real TPS signal to the specified WOT voltage.

There's not really anything wrong with the setup you're thinking of as long as you tune it. As the intake gets into the positive pressure range I believe the airflow offset (reported versus actual) will decrease. I never ran a MAF on a turboed setup, on the N/A the offset was bad across the entire range, but predictably so, so I got away with trimming most of it out with one adjustment to the mainscale.

Isn't the stock piping 2"?

[cvbikeguy]

ROFL! Man, I was just screwing with you... yeah... there is an odd pattern of me ending threads by replying to them. I hope it's because I've satisfactorily answered the questions, but sometimes I wonder if it's just because everyone else is fed up.
lol

hey cre did you notice a difference putting the maf on your n/a?