I have had numerous people contact me regarding how to modify their systems for more boost. Also people want to know how to install larger blowers that were never intended for the C4 chassis.

Well, I had mine apart for the powdercoating, and figured I would snap some shots. These mods will work for all manufacturer's blowers, but you may have to be a bit "creative".

First is the shot of the standard D1 Procharger mounting bracket.

It uses five (5) mounting bolts and stands the blower somewhat upright. Look at the idler placement, and you can see that even though ATI has designed fairly decent beltwrap (into the D1 bracket), it could be improved. In my experience, the P600B will instantly gain 2 psi by modding the bracket. Some Vortechs will likewise have the large gains.


Here is a comparison of the bracket that I run vs the ATI unit. Even though this one is for the R-series (3/4" greater length in the center section), the concept is still the same. It uses seven (7) blower mount bolts and "tilts" the blower slightly to gain the needed hood space and get the bottom of the trans off the top of the shock tower. And yes, the volute has to be rotated slightly to still align. Easy task. It also has a 1.5" strengthening rib mounted in a "t" configuration on the backside of the bracket for strength.


You may notice a bit better belt wrap in this design, though the two faces of the belt tend to run very close when mounted on the car. I left the minimum amount of space between the two pulleys that would allow the belt to be changed without removing pulleys.


A better shot of the blower mounted in the bracket.


This is the blower package mounted back in the car. You will note that evrything is fairly compact, and all fits under the hood. I still get some very slight amounts of dust off of the area, but I am seeing nearly 20 psi using a factory 6 rib by 5000 RPM. And more importantly, I am seeing almost 5 psi by 3200 RPM.

I hope this has helped with some of the explanation of what it takes to fit a larger blower in the compact space, while also addressing the "belt wrap" issue. I have modified so many brackets, that it make me wonder wht ATI and Vortech do not push the idler up next to the driven pulley.

And last but not least, a completed shot of "ol Yeller" following the powdercoat of the intake ducting and blower brackets.


Aaron

 

Nice job on your bracket build! I like the idea of a back brace on your plate. Did you take any pics of that?

I was thinking i can get a little more wrap by just increasing the diameter of my idle pulley. Also part of my low psi is I have an underdrive pulley system on the car & that means a smaller than stock crank pulley which reduces overall belt speed.

 

another thing that is worth noting- anywhere you have long lengths of belt without idlers you may get the belt moving around a bit. It's mentioned in gregs sales guide.

After looking at your pics, do you have any issues fitting that ducting and huge air filter under a stock hood? Also, are you just running one vortech mini race bypass?

 

The strengthening rib runs from the lowest inboard head bolt hole and incorporates the spacer, and travels outboard to the trans area of the blower. Sorry, I didn't get pics of that.

My choice would be to change the drive pulley, as this will increase boost and decrease belt slip. This will do more than the idler change.

All of that ducting and the filter fit under the factory hood. The ducting (buna hose) is from ATI, and the K&N was orderde locally. I run two blow-off valves. One underneath, and one out front. I am not blowing the duct loose under high psi, which means the b/o valves are doing their job, or the silicon hoses are much more secure. Probably the latter.
Aaron