[Swerve]

While I've got everything apart I decided I would Gasket match the lower intake bowl, & smooth out the casting roughness from the whipple inlet & outlet plate.

Once I got the outlet plate off I saw some cut marks and a thick edge that didn't make much sense regards to flow.

Once I radiused one half of the thick edge I was really surprised at how much that opened up the outlet area. I removed the sharp cut from the walls & blended the walls into the opening under the thick edge, then I removed the casting roughness with an 80 grit flapper wheel from the ramp. I removed the casting roughness from the underside of the plate using an air grinder with a surfacing wheel & 80 grit.

I'll go back over everything with 120 grit flapper & surface wheel then again with the little brillo pad looking surface wheels.

 

[posi]

Gotta love whatever hp you'll get from doing it yourself and with free labor. Looks good.

 

[boosted2000si]

Looks good. I wonder how much better it will flow.

 

[eschaider]

Eric,

As you do the clean up and matching on the mounting plate try not to modify the actual exit port coming out of the blower. The way the blower manufacturers establish a blower's internal pressure ratio is by manipulating the size and position of that exit. If you increase the area you lower the pressure ratio and if you decrease the area you effectively raise the blower's pressure ratio.

Both KB and Whipple have tuned the pressure ratios on their blowers by manipulating the dimensions of this port. The KB "H" blowers that operate more efficiently at higher manifold pressures do so because of manipulating the exit port dimensions to achieve the internal pressure ratio target they were looking for. Whipple did not use an "H" designation but instead referred to the blowers with a different pressure ratio as Gen II units and in fact they also operated more efficiently at higher pressure ratios for the same reasons.

Ed

 

[Swerve]

I didn't get any pics of the deep grooves that were in the walls before I started. It looked pretty ridiculous though to have a 90° end mill cut into the face of the walls though.

Initially I figured I'd just sand off the casting roughness, but once I saw the grooves & that thick edge I got some other ideas.

Basically air exits the blower at the front of the case. That ramp directs it towards the middle of the intercooler, so air is making a 90° turn around what was a sharp straight edge. You can see by the first pic how much area was opened up just by radiusing the edge.

My baseline is a 10.1 at 135 footbraking from 2k rpm with the stock longblock, but as typical with these types of mods, I'm changing other things too so who knows.

 

[Swerve]

I did not touch the port end that is gasket mounted to the bottom of the blower aside from smoothing the cast roughness. I won't be touching the blower case itself either.

It's hard to say this plate is part of the pressure ratio tuning. It's quite literally as cast and they zipped an end mill along the long edge not paying any attention to the groove that the end mill put into the walls of the port. I went into this thinking worst case, I can buy a new plate from whipple since that's the only thing that changed.

Eric,

As you do the clean up and matching on the mounting plate try not to modify the actual exit port coming out of the blower. The way the blower manufacturers establish a blower's internal pressure ratio is by manipulating the size and position of that exit. If you increase the area you lower the pressure ratio and if you decrease the area you effectively raise the blower's pressure ratio.

Both KB and Whipple have tuned the pressure ratios on their blowers by manipulating the dimensions of this port. The KB "H" blowers that operate more efficiently at higher manifold pressures do so because of manipulating the exit port dimensions to achieve the internal pressure ratio target they were looking for. Whipple did not use an "H" designation but instead referred to the blowers with a different pressure ratio as Gen II units and in fact they also operated more efficiently at higher pressure ratios for the same reasons.

Ed

 

[Swerve]

All polished out. I took the air grinder with a brillo pad surfacer to the entire bottom surface of the plate too.

I'm not seeing a whole lot of room for improvement on the inlet yet.

 

[04sleeper]

Eric,

As you do the clean up and matching on the mounting plate try not to modify the actual exit port coming out of the blower. The way the blower manufacturers establish a blower's internal pressure ratio is by manipulating the size and position of that exit. If you increase the area you lower the pressure ratio and if you decrease the area you effectively raise the blower's pressure ratio.

Both KB and Whipple have tuned the pressure ratios on their blowers by manipulating the dimensions of this port. The KB "H" blowers that operate more efficiently at higher manifold pressures do so because of manipulating the exit port dimensions to achieve the internal pressure ratio target they were looking for. Whipple did not use an "H" designation but instead referred to the blowers with a different pressure ratio as Gen II units and in fact they also operated more efficiently at higher pressure ratios for the same reasons.

Ed

Very interesting Ed. That's the first time I have read that.

Is this something the blower manufacturers don't want us to know about?

 

[Swerve]

Very interesting Ed. That's the first time I have read that.

Is this something the blower manufacturers don't want us to know about?

KB posted that a few years ago in response to Steig offering a KB port option. I know of one 2.2 that steig rebuilt and ported but unfortunately the person who sent it to him never even ran it. He sold it off and I never did get to hear how it performed.

 

[GodStang]

Very interesting Ed. That's the first time I have read that.

Is this something the blower manufacturers don't want us to know about?

No this is info that has been out for some time. At least 5+ years but not a big topic talked about.

 

[eschaider]

Very interesting Ed. That's the first time I have read that.

Is this something the blower manufacturers don't want us to know about?

Actually, as a number of the other guys have already pointed out, it is not Kevin. In fact there is a fair amount of information floating around different websites about twin screw compressors and how they do their magic.

The compressor's internal pressure ratio is set by the manufacturer to optimize the compressor for the operating environment it has been developed for. Changing that outlet port location and geometry will modify that pressure ratio.

When KB and Whipple went to higher pressure ratio's, the high ratio compressors made more power at higher manifold pressures than the same compressor with a lower internal pressure ratio because the compressor could operate closer to its high efficiency center island performance on the compressor map. The lower internal pressure ratio compressors, not surprisingly, outperformed the higher pressure ratio blowers when used on an engine with lower manifold pressure.

It's sort of old science but not often talked about.

Ed

 

[fasteddy03]

Just happened to pull my mounting plate off a 2.8h. KB uses a cnc'd opening. Looks much prettier. I'll take a pic in a little bit.

 

[fasteddy03]

bottom

top

 

[04sleeper]

Actually, as a number of the other guys have already pointed out, it is not Kevin. In fact there is a fair amount of information floating around different websites about twin screw compressors and how they do their magic.

The compressor's internal pressure ratio is set by the manufacturer to optimize the compressor for the operating environment it has been developed for. Changing that outlet port location and geometry will modify that pressure ratio.

When KB and Whipple went to higher pressure ratio's, the high ratio compressors made more power at higher manifold pressures than the same compressor with a lower internal pressure ratio because the compressor could operate closer to its high efficiency center island performance on the compressor map. The lower internal pressure ratio compressors, not surprisingly, outperformed the higher pressure ratio blowers when used on an engine with lower manifold pressure.

It's sort of old science but not often talked about.

Ed

Thanks Ed. I may have read it somewhere but just didn't remember it. That does make sense.

Thanks for the explanation.

 

[Swerve]

Fasteddie: That does look nice. Interesting that the KB plate has that same thick hard edge on the inside.

 

[fasteddy03]

I think I am gonna radius all the corners just a bit for a little smoother transition.

 

[Swerve]

That was my thinking also. The cuts into the walls of the whipple plate were much worse though.

I also surfaced the entire bottom side of the plate because it was all as cast rough. It's now smooth and lightly polished. Not as smooth as the ramp in my picture on the previous page, but smooth enough.

I'll do the same thing to the inside of the intake bowl also.

 

[lucheski]

Did you do any port/polishing on the inlet side?

 

[Swerve]

Not yet. I've been tearing the engine down. Next up, I'll port & polish the lower intake bowl. Then I'm going to make a jig to measure the wall thickness of the inlet elbow so I can try to maximize the area around the bottle neck.

 

[Swerve]

I started cutting on the whipple inlet. I rigged up a way to measure the wall thickness. Don't laugh. :rofl:

The wall thickness untouched is .250" minimum.

So far I've cut 3 walls & 4 corner radii to .140"-.150". The top wall is currently at .170". I cut a LOT away from the hump under the top inlet bolt bosses shaping it to be less of a disturbance. I also removed the ridge from the top where it meets the blower. I'd like to get all of the walls down to .130" but it goes so slow shaving .010" from an entire wall at a time. It's nothing at all like cutting material away from an edge.

I focused only on the bottle neck of the elbow. I didn't see any reason to spend a bunch of time thinning the wall before the bottle neck. Instead I just want to increase the area at and right before the bend. I'm going to shape down the middle bolt boss hump also.