OdessitPashka

Question for the people that have boosted their beta with MAFs and have a BOV.

When you press your clutch BOV releases pressure in pipes but MAFs still reads that a lot of air is going through it therefore adding fuel into your cylinders, which will cause your car run really rich. How can this be solved? I heard of some special BOV being adopted for it....

and couple more questions, I just dont want to start a new thread because of it.

Would stock FPR be able to deliver enough fuel for 160-170whp? I plan on going low boost at first, 4-5psi on t3. and another question regarding lowering boost level, how can it be lowerd with external and internal wastegates? I know you can change a spring inside of it, but could I lower it with electronic boost controler?

Thanks a lot
Pashka

drafter

First question,

You use a recirculating BOV, just like what most stock turbo'd cars use. You recirculate to before the turbo inlet but after the MAF sensor. This keeps the air in the system. Look for a first gen eclipse turbo BOV.

Second question,

the FPR would pe fine for that, but, you shouldn't use a higher flow pump (except maybe the turbo dsm pump) because the fpr would cause the pressure to rise too high.

Third question,

you can not lower the boost pressure below the wastegate setting with a boost controller, only raise it. With an adjustable internal wastegate, you can raise or lower it because it is on a threaded rod, you just spin the rod. External wastegates need different springs which you can order from the wastegate manufacturer.

OdessitPashka

thanx a lot for the reply smile.gif
but i still have couple questions to you
I will still place BOV after the turbo and before the TB, and all i will have to do is just route a line to the hole that will be inbetween the mafs and before the turbo inlet? is that correct?

I shouldnt be running lean with stock FPR, should i?

So I should just get a turbo with adjustable internal wastegate! that would be the easiest and the cheapest way to go!

Thanks

drafter

Yes, there will be a tube between the BOV to a fitting on the intake pipe, between the maf and turbo inlet.

You won't run lean, but if you put in a higher flow pump, you may put too much pressure on the injectors which will cause a higher flow through them, but much more unstable. Going lean has little to do with the FPR, and I think you are confusing the situation. The FPR will not add more fuel when you are on boost. In fact, you will need to put a check valve between the intake manifold and the FPR to keep it from slamming shut under boost. You need some sort of fuel management (for the 4-5 psi you want to run, get an SAFC).

I would go with some type of t3 (I don't know your budget) that has an adjustable internal wastegate. The only problem I see is that you may not be able to get an adjustable wastegate that will run that low.

Also, keep in mind that it is not the total pressure that is most important, you need to worry about the airflow. The amount of air is what is raising the power, not the pressure ratio. Different turbos can provide different amounts of airflow at the same pressure ratios. I wouldn't worry about 4-5 psi unless you can find an adjustable wastegate that can run that. I would just get a t3 that has an adjustable wastegate that can go down to at least 7 psi and get it dyno tuned. It kind of sounds like you may not plan on dyno tuning it. Don't do that, spend the extra $100 bucks and dyno tune it. It is well worth the money and peace of mind. Any more questions, feel free to ask, I may not know the answer, but there are plenty of other people that do.

OdessitPashka

Yeah, I didnt think about dyno tuning it neither i was planning on SAFC since i thought that 4-5 psi wouldnt be a big deal. I just want to get a cheap setup for now and then be able to upgrade. Dont wanna go all the way right away, not ready for it yet.
Would stock fuel pump be able to support 7psi of boost on a t3?
Can you give me more info on check valve that I'm gonna have to add?
What kind of tuning will be done at the dyno? I know they will be correcting my A/F ration, but how if im not gonna have a SAFC? Would they be able to tune it with just my stock FPR? I want to know what exactly they will be doing to my car.

Thanks a lot

OdessitPashka

bump and update!
i found a BOV from 1st gen eclipse like you said, but I dont see anything where I would be able to put some hose that will go to the pipe after MAFs before turbo. Or would I just have to connect the only hose to that new location?
EDIT, how is 1st gen eclipse is any different from any regular BOV that you can get off ebay for $50? it still have the same piping...

http://cgi.ebay.com/ebaymotors/ws/eBayISAP...&category=33742

Thanks

batman

well i was wondering how would you go about an open BOV or can it not be done on the tibbys? because the PSSSSS sound it one of the best things about a turbo, besides the hp

OdessitPashka

it can be, but IMO this sounds gives out that you have a turbo... i want to have some kind of sleeper....

drafter

No, the pssssst sound is not the best thing about a turbo, the gobs of torque and horsepower are. You should not do an open-air blowoff valve on a MAF sensor based engine. The reason...

The air flow meter has already measured the air and is expecting it to get to the motor. If you vent that air to the atmosphere, fuel is added but wait, the air is now vented to the atmosphere. We all know what happens when you get a ton of extra fuel and no air.... rich running conditions. It can get so bad as to stall the car. Most likely it will cause the car to bog down very bad and you will not run as efficiently. It will make it difficult to keep your revs up between shifts. You will get carbon build up, and eat up your cat.
Furthermore, you do not need the open air BOV to get that sound, as long as you use some type of open filter element, the sound will travel out of the filter and you will hear it. It will sound a little different than most open air BOVs, but it will sound good.

That first gen DSM piece looks good. If you want it, jump on it. And yes, you will connect the hose from the BOV exit to the intake. These are actually called bypass valves, instead of blow off valves. The term is often used interchangeably.

OdessitPashka

So from what I understand, you put your BOV before TB and after intercooler, then connect one of the hoses to the pipe where your BOV sits on, and connect another hose all the way to the pipe that goes between MAFs and a turbo inlet. is that correct?

thanks