Author Topic: Blow off valve ??? (Read 9144 times)

gsxrcop · « **on:** January 02, 2009, 11:17:42 AM »

Hi, have a project going on a 1991 318IC. I have so far a t3/t4 hybrid turbo, good & tight manifold, 12:1 FMU, FMIC. I plan on running between 5-8 psi with this setup. My question is this...I have heard that running a AFM on this setup that I don't run a blow off valve. Is this true? Any help or advice would be great.

ludiagsm · « **Reply #1 on:** January 02, 2009, 11:27:30 AM »

Quote from: gsxrcop;63879

Hi, have a project going on a 1991 318IC. I have so far a t3/t4 hybrid turbo, good & tight manifold, 12:1 FMU, FMIC. I plan on running between 5-8 psi with this setup. My question is this...I have heard that running a AFM on this setup that I don't run a blow off valve. Is this true? Any help or advice would be great.

Hi ,if you make turbo car you must use blow off valve.

gsxrcop · « **Reply #2 on:** January 02, 2009, 11:58:00 AM »

So the plan is to just take the cone filter off the intake side and install it on the turbo inlet. Take the intercooler piping right off the AFM and install the blow off valve right after that. Will that work ok? Most all of the pics I see of M42 turbo set up's must be using standalone, because they have no AFM.

bearsbmw · « **Reply #3 on:** January 02, 2009, 12:09:40 PM »

Quote from: gsxrcop;63881

So the plan is to just take the cone filter off the intake side and install it on the turbo inlet. Take the intercooler piping right off the AFM and install the blow off valve right after that. Will that work ok? Most all of the pics I see of M42 turbo set up's must be using standalone, because they have no AFM.

Blow off valve befor the AFM allways assuming you have the afm after the turbo ... if you are good with components you can even do a crude tune with the AFM if you open it up and play with the door flaper...Unfortanly when your using the Rising rate regulator there is a dead spot (Lean out) from 1-3 psi and playing with the AFM can almost eliminate the dead spot but only do this if your realy confident with your work... You can run 8psi safely with the 12:1 ... 9psi was starting to lean and 10psi I hit engine knock... good luck

gsxrcop · « **Reply #4 on:** January 02, 2009, 12:21:42 PM »

So right out of the intake do the BOV and then the AFM? What do you mean assuming AFM after the turbo? The turbo is on the other side of the engine.

Quote from: bearsbmw;63883

Blow off valve befor the AFM allways assuming you have the afm after the turbo ... if you are good with components you can even do a crude tune with the AFM if you open it up and play with the door flaper...Unfortanly when your using the Rising rate regulator there is a dead spot (Lean out) from 1-3 psi and playing with the AFM can almost eliminate the dead spot but only do this if your realy confident with your work

bearsbmw · « **Reply #5 on:** January 02, 2009, 12:30:53 PM »

Quote from: gsxrcop;63884

So right out of the intake do the BOV and then the AFM? What do you mean assuming AFM after the turbo? The turbo is on the other side of the engine.

some people rewire the AFM and put it on the induction side of the turbo...In your case you will keep the AFM in the same spot it came factory and you will place the blow off valve befor the AFM between the turbo + side and AFM

gsxrcop · « **Reply #6 on:** January 02, 2009, 07:48:25 PM »

Does anyone have a pic of this set up for me to see? All of the ones I have seen have a custom intake manifold.

romkasponka · « **Reply #7 on:** January 03, 2009, 09:06:26 AM »

Quote from: ludiagsm;63880

Hi ,if you make turbo car you must use blow off valve.

No, thats not true. You dont need it. You need it only if you want blow off dust under hood. Toys for kids...

Boosted E30 · « **Reply #8 on:** January 03, 2009, 01:32:53 PM »

Quote from: romkasponka;63944

No, thats not true. You dont need it. You need it only if you want blow off dust under hood. Toys for kids...

if you want your turbo to last you definatly need it.

romkasponka · « **Reply #9 on:** January 03, 2009, 01:49:12 PM »

Quote from: Boosted E30;63962

if you want your turbo to last you definatly need it.

Ok, please tell me how much it will last longer?

bearsbmw · « **Reply #10 on:** January 03, 2009, 02:29:00 PM »

Quote from: romkasponka;63966

Ok, please tell me how much it will last longer?

Put a turbo with no BOV on your 318is and report back with results

romkasponka · « **Reply #11 on:** January 04, 2009, 11:11:06 AM »

Quote from: bearsbmw;63970

Put a turbo with no BOV on your 318is and report back with results

I know few guys which are racing in Lithuanian open class championship with high boost numbers about 1.7bar without BOV and without ANY turbocompressor problems. 1000km in racing is it enough?
Nobody prooved that turbocompressor last longer with BOV.

WRC cars runs without WG

Boosted E30 · « **Reply #12 on:** January 04, 2009, 01:34:03 PM »

good but those are race cars! this is a street car probably daily driver. my buddy didnt have bov on his turbo car and his brand new turbo was done in 2months

nuvolarossa · « **Reply #13 on:** January 04, 2009, 02:48:34 PM »

Quote from: romkasponka;64038

I know few guys which are racing in Lithuanian open class championship with high boost numbers about 1.7bar without BOV and without ANY turbocompressor problems. 1000km in racing is it enough?

I think that 1000km in racing doesn't mean that a stock engine and turbo without bov will last enough... :confused:

Quote from: romkasponka;64038

WRC cars runs without WG

Yes, but they have this

http://forums.nasioc.com/forums/showthread.php?t=1650384

If you don't want to use a BOV venting to atmosphere and making noise, place a BPV (aka diverter, aka recirc-valve, the ones that bosch make for stock turbo cars like Porsche TT, VAG 1.8T...) they are quiet and they do fine their work.
like this:

:rolleyes:

gsxrcop · « **Reply #14 on:** January 04, 2009, 09:55:48 PM »

Thanks for the comments. I'm going to use a BOV, it's a HKS. What I still need is a picture or more info on where to place it when running a AFM. Any help?