Ericy321

Ya, when the MAF is maxed out it will run lean. Thats how mine is as well as others Im sure. Thats why I cant wait to throw that sensor in the garbage. And if a turbo setup has the BOV venting to atmosphere it will cause huge issues with a MAF unless it is tuned around. Thats a lot of air its losing and should be recirculated to a pipe pre-MAF.

sleepertib

Hey thanks for all the input guys. I had a feeling that was the case. Looks like I'm going to be recirculating the BOV then. They sell add-ons for the HKS on ebay for pretty cheap that'll let you adapt it to recirculate. So are vent to atmosphere BOV's only for MAP based cars then? When I put the SMT in, I'll be swapping in a map sensor. That won't replace the MAF though simply because the ECU will still want to read from the MAF right?

Once again, thanks everyone for the help and input! hail.gif

Alex01tib

You don't have to (and can't really) recirculate with the setup like that. Look where is MAF sensor is guys.

Recirculation takes air that has been expelled out the BOV and reintroduces it into the intake side of the turbo in between the turbo and the MAF sensor, this prevents metered air from being lost which would cause the car to run rich (because the ECU is anticipating more air than what ends up entering the combustion chambers)

In setups (like yours and mine) where the BOV is in between the turbo sensor and the MAF, the air that is being expelled out of the BOV has not yet been metered.

If for some strange reason you did recirculate the air from the BOV back into the intake stream you would just be reintroducing warmer air into the turbo to be repressurized and reheated, since an intercooler doesn't bring the charge air temp all the way back to ambient.

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And DTN, although we dont have a MAP sensor, the engine is still getting the right reading of air as long as the MAF isnt maxed out (which doesnt happen until 10-12psi). The way the MAF sensor works is by heating an element and allowing the passing air to cool the air, the voltage required to keep the element at the desired temp is directly converted to the mass of air flowing through the piping. This isn't affected by what pressure the air is, as more pressurized air can remove more heat from the element, the air molecules are absorbing the heat as they pass, more air = more molecules = more element cooling = higher air flow.

In addition, The fact that the temperature sensor reads a lower temperature than the actual air passing the element (because the temp sensor is pre turbo) actually means the ECU will add a little more fuel which is helping your cause.

Ericy321

OK, I didnt see that it was blowing off before the MAF. That shouldnt be a big issue then.

steve b

hi guys
i havent been on here for a while, iv been away building a turbo on the car. its all done now but dose have a few little problems. the main one is very similer to the one in this topic. basicly it runs fine untill i start to give it some gas. if say im in second and start to increase spped by the time i hit 3rd my air fuel is wasy to rich. the map is fine as far as i can see. when it runs rich i only have to wait a few seconds and it sorts itself out. air fuel returning to normal. then when i start to go again it dose the same. some time si goes lean and not rich. im wondering if its because i havent added a fuel pressure regulator yet (its on it way) the set is is a T25 turbo 440 injectors uprated fuel pump tuend with a aem fic. the car is a 2001 tib (with maf). could it be the fpr or is it somthing like the ecu not keeping up with the fic? any ideas would be fantastic.

Hive

Did you do both Fuel Map and O2 Map? I have found out that most of my problems with FIC are being there because all of the fueling is done by just fuel map. I will be doing my O2 map this week and hopefully this will solve my problems ;-)

steve b

the guy that is doing most of the work is due to do somthing with the o2 sensor in the next week or so. i must admit im not that clued up to how it all works but i have a good friend how knows alot. him and and a local garage have been bulilding it for me and im lurning as i go. thay both have said that the o2 sensor is probabily the problem and are planning on doing this next. the car drives fine its just when it comes on boost it plays up. we have clamped the maf voltage done the fuel map ect. its at 8psi at the moment and had a quick dyno run. results was 168 whp which wasnt to bad for a very basic tune. its all still very much a work in prosses. apart from this one problem its working great. the other thing it dose is bad starting. when i say bad i mean it takes a few seconds to of cranking to start up. it also needs a ecu re set every now and then because the ecu seems to fight with the fic. im guesing all these little problems is what comes with projects like this? its anoying but kinda fun at the same time. im loving it really lol. problem we have is over here in the uk no one really seems to do this sort of thing to these cars. i dont know of anyone else in the uk that has turboed an rd 2 and from what ive been told i have the only fic on one of these cars in the country. how true that is im not sure. anyway ill get the o2 sorted, fpr fitted and see if that makes any differance.

Hive

I am almost 100% sure that most of your problems will be solved by doing the O2 map. THough I am not sure for bad starting but ECU fighting the FIC will be solved I am sure.

daneeboy83

Hey guys

And what happened?

Do we have answers to the problems?

I would like to know since what you guys did is what i wanna do too.

But i wanna know what you ended up doing.

stealth

^^ i dont think they have done anything yet, they are still working out their problems first as this was just posted yesterday

what they think is the problem though is only having one map set up on the fic, he needs the o2 map and thats what SHOULD fix his problem. If thats what you're wondering