Go Dog Go
The trend on the flow bench was that the thicker the spacer the more the flow increase. The 1/4" spacer was worth something like 16 or 17 cfm and the 1/2" was worth 30 cfm and we tested a stock upper manifold to get a base line and then tested a ported upper manifold. The ported upper manifold was only worth 14 cfm or so. In other words the 1/4" spacer was worth more on the flow bench than the 5 or 6 hours worth of grinding I did on the upper manifold.

When I ported the upper manifold...I didn't mess around. I have 1/4 horse die grinder and some 1" diameter burrs and a can of WD-40 and I made a mess . I widened the manifold from the inside until I broke through the bolt bosses and had to weld it up and then raised and reprofiled the roof of the manifold as much as I could. All of that grinding and reshaping was worth very little, but here is were it gets interesting.....when the manifold was being tested on the flow bench, John started building up the floor with modeling clay and reshaping the floor and the short side turn and the flow started to take off.

The manifold that is on my truck now, has had the whole top cut out of it and has been recontructed in sheet aluminum and the shape of the curve at the back of the manifold is completely different than stock. The stock manifold uses a series of flats that turn the air and it doesnt really turn the air 90 degrees into the blower inlet.....it just sort of turns the air about 50 or 60 degrees and then slams it into the back of the blower inlet. My manifold turns the air a full 90 degrees into the blower. The floor of the manifold has probably 1/2 thick epoxy at the short turn just before it enters the blower. And Yes I will get some pics of it, maybe as soon as this weekend.
Hope this helps
Dale

 

Anyone?

Magnuson says the bypass is for economy, Ford manual says it is for safety...Do all blowers have a bypass valve?

 

easterisland
I think the bypass is very important especially if you street drive the truck at all. If you cover up the bypass you wont loose anything except bypass. The bypass is there to take a lot of blower drive pressure off of the engine and it improves fuel economy alot, but as a hot rodder, what I really like about the bypass is that it makes the blower run waaaay cooler than without it.

Have you ever unplugged the vacuum source from the boost canister while the engine is running? Try it sometime, it will give you and idea of what it would be like without it. It puts more strain on the engine but the throttle response IS better.

Somewhere on one of these blower porting post I gave my method of making the boost bypass react quicker to throttle response. It works

As far as my blower is goes.......I didn't do anything with it, I was tempted to weld in a curved piece of aluminum plate to cover most of it up but still keep it active, but I never did. Maybe over the winter I will take another look at it.
Dale

 

Well, I filled the bypass hole with JB weld. Just the top half. If I need to I can drill a hole and have a bypass again. I'll see how it all works. I do have temps probes for temp out of the blower before the intercooler and for temps out of the intercooler so I can measure as soon as I put everything back together. I guess now I won't have to unplug the boost bypass solenoid. Next step get a 1/2 inch spacer and block off plate for the egr.

 

easterisland
Another way to block the EGR is to get yourself a 1/2" pipe tap.
The hole in the manifold is almost the right size (maybe even a little big) just tap it and put a socket head pipe plug in there.

I did the racey thing and got an aluminum blue anodized plug from Earls. Its much lighter than the steel or brass plugs
Dale

 

hey guys, what does blocking off the EGR do?
easterisland-post back and tell us how the truck runs with the blocked off bypass. i did the same thing but took it out before i put it back on the truck b/c of paranoia.
and does anyone make spacers for the upper and blower case?

 

hey when is this etown thing i wanna watch the lighitnings run there, i was at import nats. and the street wars. im a big fan of imports and domestics i may get a lighitng too. i don't race my car much got my timeslip (12.8 @ 115) but i need another clutch again, i can't keep buying stock ones lol.

 

easter - from what I read, I believe the KB blower that JL was testing had no bypass, also I think one of the prototype Works blowers didn't have a bypass also.

Not that I know off. I'm going to make one myself this week.

 

Capt.
I'm surprised one of the tuners haven't already jumped on this spacer thing. I have posted about it before a couple of times in the past year and it has just now been noticed by a few peaple. It really does help. Its not huge, but it is an impovement.
Dale

PS I forgot to answer your email at work.....yes you can have the pictures and I will try to get more. Looks like my upper manifold on my truck might be of some interest. And the spacer setup that I currently run is a 1/4" that is epoxied onto the blower case....because of the recontoured upper manifold that is all I have room for. I know the pictures showed 2 spacers but that isn't what I run right now. No hood clearance.

 

Bad As L

Some very interesting points you have made.
Even though its like comparing apples to oranges............
Back in the early 80's I did a lot of experimenting with Harley heads and intakes. I found out that you can take too much metal out, you lose velocity, now maybe this wouldn't happen with forced induction. But we made tremendous gains with adding metal to the "floor" of the intake.
We also did the spacer routine between the carb and intake, thus increasing the plentum. Old school ideas.
I DO think you are on the right track, thats why the aftermarket blowers are more responsive.
Thanks for sharing your ideas and pics

 

Bruce - I think you're right about that. However there are some places that look like they will benefit greatly from less material. From what Dale said I'm really glad I only removed the roughness on the upper intake plenum, instead of trying to open it all up.

Heres the pics that Dale sent me so far, for those curious:
http://captainoblivious.tripod.com/truck/dale/dale.html

Dale - theres a metal type shop near me, I'm going to see about getting a spacer made from them. If not I just make one myself. When you say no hood clearance, do you mean both the ¼" spacer and ½" spacer??? Because I was going to go with just a ½" spacer.

 

Bad as L, What year is your truck? Looking at the pics that the capt. posted, did you drill extra holes in the blower to intake area? Or, are those holes stock?

Also talking about the blower kinda I'm trying to get rid of some emmisions control stuff. I'm going to use breathers on each head, do I need the tube going from the back of the lower intake to the upper intake plenum? Is this some type of pressure equalization thing?

 

badasL- seeing that nobody else makes the spacers, you ever think about making some and selling on ebay? im sure a bunch of us would go for that?

 

easterisland
nice catch...my truck is a 00' but I have the 01' lower manifold and no I don't think it made any difference. The intercooer did tho. I even thought about doing some port work on my stock 00' lower manifold and doing a back to back.

capt.
I know the picture looks a little confusing but the 1/2" spacer is about the most you can get in there with a stock upper manifold. And dont forget you have to make spacers for the 2 front legs of the manifold also ( I just used 3/4 round stock, aluminum) The blower case that is in the pictures has a 1/4 inch spacer glued in place and had not been finished yet, once it was blended in it looked like part of the blower case ( from the insided anyway)

Once you see what I have for and upper manifold you will understand why I couldn't use a full 1/2".

wkuper 11
I thought about making spacers if the idea ever caught on. But right now it would be kinda hard. I do all that kinda stuff at work and right now it is just to busy for that. I'm the guy that designed and built the first few hundred clunk washers but I dont even do that anymore. Herb is contracting those out to some one else.

Fast Gator
Air flow is all the same.....wether its flowing down the intake port of a pro stock or just trying to get more of it into the top of our blowers. If you dont give it the right shape ...its gonna be lazy.
The way the factory piped the air into the top of our blowers, just plain sucks. But that's fine with me, cause I get to play with something that I now a little bit about (very little ). I feel like I have only scratched the surface here. There is a lot more that could be done with the upper manifold even in the space confines that we are working with. The guy who did the flow work for me actually sat down an drew some pictures to show how to get more air around that turn and what shape he thougt would work best. Who knows one of these days it might show up on my truck in carbon fiber.
Dale

 

Pete

Even though I haven't opened my blower up....here are my thoughts
Just because it LOOKS like you need to remove metal to improve air flow IS NOT allways the case
Looks can really be decieving, because as Dale said, the air gets lazy
Porting is not something that can be done by looking at and thinking "I can improve here"
Polishing is another matter

Dale

You say the fella that has done the flow work, drew a few pics of what he thought would work?
Thats the direction I would work in
I would be interested in seeing what he thinks would work and what would not. And if he thinks building up the floor of the blower would increase velocity, which in turn would move more air thru the maf and in turn tell the injectors to give more fuel