best way to bypass the maf sensor?

what have you found the most effective way of bypassing the maf sensor? I have the turbo in the same place as the c1j a 3" turbo inlet (all i could get) then a 45degree bend then the maf and a filter. I was thinking about getting a 3" dumpvalve fitting t piece to go in the 45degree bend but i dont have much room due to the ic piping. Im looking at running 18-20psi boost so does anyone know if the 25mm dv fittings are a good start? Also can i just put a filter on the dv fitting or is it better to have one either side of the maf and use the main filter?

im thinking something like these. what ya think??
http://cgi.ebay.co.uk/25mm-Mini-Oil-...#ht_2128wt_988
http://cgi.ebay.co.uk/76mm-3-OD-Alum...#ht_1486wt_905

i would also like to know this as i want to run between 18-20psi. im sure haz or trix will be along to answer this shortly.

Came up with the same idea as u gary, had 2.5 ich ali pipe going into a 32mm ali pipe at 45 degrees with a silicone hose right to the side of the radiator for loads of cold air. Brilliant i thought, ;), didnt work at all.:cry: After speaking to Haz and Scoff, the best method is a hole in the pipe right next to the turbo. start at 10mm and just enlarge it untill you get it right. Spoke to scoff about these as well:
http://store.autospeed.com/Items/144...uel%20Adjuster
Scoff put me on the straight and narrow after i failed to fully comprehend, what i was trying to achieve:ashamed: and so this could be used in conjunction with the bypass hole.
Thing is before you know it you've spent loads of money when you could of just gone standalone.

is it ok to just have a hole in the pipe with no filter etc...? or do you mean find the size of the hole you need then get a pipe sorted?

doesn't seem to like filters either, to much restriction i assume?
Literally all the setups that had had no issues and just keep going, just have a hole in the silicone hose that feeds the turbo. :eek:Dont question it, it just works :D :laugh:

A 32mm hole seems to be the magic number on the t28 larger cam, big boy setup, but just work your way up.

Cheers bud il whip me drill out:D

Ill be doing the bypass mod when ive finished fitting the t28,what would be the best injectors to use without having to solder diods in?(least hassle)also what kind of power results am I likely to see with a scoff modded ecu,e cam,large tb and t28 at 18-20 psi?

saab 'reds' +- 350cc @ 3 bar 14.6 OHM

0280150431

saab reds you say, i think i have a set of them in me tool box, ill check the numbers later. what power do you rate itl make? 200, 210??

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Originally Posted by REGGY5GT

200, 210??

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:agree:

sweeeeet:burnrubber:

I have roughly the same set up with saab reds but an ep cam. id be happy with anything over 200bhp.

Feck im lagging behind now chaps, gonna have to get this t28 on mine, no point in having the best looking but slowest car on track :cooter:

I've putting a T3 off a rs turbo going on mine, the injectors im using are off a 1.8T vag, they deliver 289cc which is about spot on for 200bhp (Scoff tells me :agree:) Might have to arse about with the fuel rail to get them to fit though :crap:

i have 315 cc injectors ready to fit

0280155759 16 Ohm

http://www.injectorcleaning.co.uk/flow.htm

Mine are bosch orange from the t5, i think they are 310cc so should be up to 200hp to, can anyone confirm this.

I looked on that list but no colours.

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Originally Posted by sieger

i have 315 cc injectors ready to fit

0280155759 16 Ohm

http://www.injectorcleaning.co.uk/flow.htm

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what are they out of mate??

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Originally Posted by REGGY5GT

what are they out of mate??

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Think there out of something like the volvo S70/V70 T5's i think.

just the man, andy, ive just been reading up, will the saab reds overfuel as im only going to be running around 18-20 psi, what i mean to say on normal non boost driving will they overfuel as i dont want borewash?? would i be better off using another injector with less cc per min??

I had the saab reds in mine for a bit before the clutch was fecked. On idle they behaved great, 13.9 on the afrs on idle. Cant realy comment on the continuous use of them as i didn't do enough miles before i split the car apart.

was that with a 32mm bypass hole??

i used the reds on standard boost levels, without a bypass with no problems.

andy i have the saab reds I have only just started the car since fitting the reds and t28 but is running really rich all over the rev range. I have made a hole in a spare piece of tube connected to the maf sensor, but am i right in thinking that this will make little difference at idle?

can someone please tell me what does what to the fueling and when? So when will adjusting the maf sensor change the fueling, the bypass hole and anything else that may need adjusting to sort the fueling?

The beauiful words of scoff::)
The whole point of running a bypass after the AFM is so that the ECU only see's maybe 2/3rds of the real airflow, but that the AFM signal continues to rise once you've exceeded it's normal limit.

Imagine that the standard AFM maxes out at 140hp, say. IE, at 140hp's worth of air flow you've got the full 5v output from the AFM going to the ECU. It can't read anymore air than that, even if you put 280hp's worth of air through it would still read only 5v. Now lets say you inserted a bypass that's of equal size to the AFM. Now you have only 50% going through the AFM, so for 140hp's worth of air you now have half the output, IE 2.5v. So at 280hp we're back upto 5v, maximum output.

So as you can see its a big bodge and your never gonna get it 100%. just got to keep adjusting the size of the hole and remember the results on the afr gauge in relation to the revs. On idle use the screw on the afm to get it were you want.

also when creating the hole you want it as far away from the back of the afm as you can.

thanks andy, all this info is going to come in useful for when im setting up, im going to try the reds without a bypass first and go from there.

Cheers bud great help.;) looks like ive got to turn the maf back down then then fiddle about with the hole:D

10's at idle may be a bit rich:scared::laugh:

Just so ive got this right then,the bigger the bypass hole the less it will fuel on normal driving and WOT as its not metering the air?

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Originally Posted by REGGY5GT

Just so ive got this right then,the bigger the bypass hole the less it will fuel on normal driving and WOT as its not metering the air?

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Yeah exactly, but remember that your using bigger injectors, that allow more fuel into the chamber, so it's just getting the balance right.

Cool,so all ive got to get now is a wideband afr,andy what are the figures I should be aiming for on the afr on idle,normal driving and wot?just so I dont melt anything or overfuel,many thanks.

Same as the c1j 14.7 idle 13-14 normal driving and 12 at wot. Got my car idiling in the 12's earlier (still cold) but didnt want to let it warm up properly as I dont have my clocks in to keep an eye on temps. I tried it without a bypass just to see what happens and it basicly flooded the engine n didnt want to start again:rolleyes: I have made quite a large bypass hole but it needs to be bigger 32mm like you said andy seems like it will be about right.

Hears an article on afr's;)
https://www.rtoc.org/boards/showthread.php?t=4761

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Originally Posted by SCHWARTZ

Same as the c1j 14.7 idle 13-14 normal driving and 12 at wot. Got my car idiling in the 12's earlier (still cold) but didnt want to let it warm up properly as I dont have my clocks in to keep an eye on temps. I tried it without a bypass just to see what happens and it basicly flooded the engine n didnt want to start again:rolleyes: I have made quite a large bypass hole but it needs to be bigger 32mm like you said andy seems like it will be about right.

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Can you take some pictures of this gary, where it comes from and where it goes :)

Will do bud. I have a different set up where the turbo is in the same place as the c1j. I have a hose coming of the turbo an straight to the maf sensor thats where the hole is. I think the hole may be to close to the maf sensor on mine but I only have a 3" long pipe so theres no other option.:rolleyes: