Thread: Interesting, question regarding draw thru vs. blow thru.

I'm curious about draw thru vs. blow thru...

I have a friend here that drifts his s13, with a blacktop swap. He's got the MAF located in a draw thru position, with the BOV un-recirculated.

I went for a ride with him, and experienced ZERO issues with driveablility. Why is it that everyone claims that the car will not run correctly if the BOV isn't recirculated on a draw thru setup?

Granted, I prefer blow thru in case a coupler pops somewhere, I can still drive the car, but I just don't see the big deal. It ran VERY nice. If it runs rich during shifting, at the most, how does this really effect total driveability?

All my 240sx buddies run draw thru with open BOV(on hot side) and also have no problems. But a few of them have comp surge too..I think stiffening up the spring is what helps but bewteen shifts that do run rich and have that backfire pop...

I never ran my turbo set up with the BOV recirculated. My car never had any issues with stalling of anything for that matter. I was using a Type S. That issues can be tuned out easily.

yeah by simply adjusting the bov to where its closed at idle not open until boost is built and shifting, you pretty much take out all that issue. Now with a soft bov you will have issues. My buddy runs a HKS ssq and has no problems at all with his. Then another buddy is running a Tial set way too soft and his will almost stall out in between shifts or when coming to a stop because it doesnt shut all the way. It all depends on your entire setup really. And yes it can be tunned out pretty easily also. Those running the SAFCII really shouldnt have problems at all.

I personally love the blow through setup and have been using it ever since with no issues at all.

It depends on the BOV. When I tried running my setup draw through with the TiAL 50mm, it caused problems. Mainly because the TiAL opening / closing spring pressure is determined by how much vacuum your engine is drawing e.g. you need a different spring for stock cams versus S4's. There is no adjustment like the Greddy or HKS. It is setup for blow through now, and all is well in the world.

I have years using draw thru, never had any problems... I just dont like the idea of putting pressure on that plastic MAF, i would not like to damage a Z32 MAF here, its very difficult to get one.

i dont see how a maf could possibly get damaged if you run it blow threw. i would think you would blow of a coupler before the maf it self cracked or got damaged.

ive ran both draw and blow, currently running blow threw and i love it. my bov is located on the charge.

stratton.

Yep, my car was draw through with a Tial BOV when I got it. It ran great, but it had compressor surge like a muv hugger.



Exactly. It's certainly possible, but depending on the BOV you've got a pretty good chance running into idle issues or compressor surge, one of the two. I hear cars all the time zzzzzzzzzzzzzzzZZZZZZZZZZZZ-CH-CH-CH-CH-CH-CH-CH-CH-CH, lol.

yeah i dont think the maf will give before a coupler will. I mean there are guys running blow through at well over 20psi on a Z32 maf and no problems at all.

just curious whats compressor surge, I could search but I'm lazy lol