We are not knocking the Rousch kit, but the sale on the Whipple is insane. You get a larger supercharger of a more efficient design. The M90 on the Roush is similar to the factory SC used on V-6 cars like the Thunderbird SC and the GM 3800 cars.

The Whipple 2.3L is what Cobra and Lightning guys were putting on their vehicles to replace the M112's. (THe M112 is larger than the M90).

 

Roush uses the M112, not the M90 like Allen used on most of their stuff.

 

Called JDM and looks like I'm going whipple... Going to get some 39lb injectors as well as a smaller pulley and custom tuned for it. Thanks guys!

 

boost it!

 

good choice

 

I just installed my Whipple kit from JDM. You will not be disappointed. I'm still waiting on the new tune to throw the 39# injectors in but even the stock kit is a healthy increase in power. i can't wait to see what its like with the new tune.

Tim

 

I plan to install everything at once, long tube headers, 39 lb injectors, supercharger, and custom tune. I should be in for a surpirse..

Any comments and/or suggestions to running a single 3" exhaust with a S/C? Good/bad? I have OBX long tubes with hi flow cats that have been waiting to be installed with a Borla muffler.

 

Another one saved from a Heaton
You will love the Whipple and it is ready to grow with you! Enjoy. Personally I think JDM needs to send me a check. I think I have helped sale 4 of these things for em by bragging about the discount for them.

 

Man, I sent you a check but it was refused by recipient. How about I just do a big smokey burnout in your honor? Would that be good enough? LOL

Tim

 

AHHHH resend the check, musta been my neighbor f'n with me

 

I'm assuming that since you said a smaller pulley you are going with the 3.125 (10psi) instead of the 3.325 (8psi)that comes with the kit. You are on the right track with the longtube headers. They are good for anywhere from 20-30hp. However there important role is not making power but keeping the valves cool. Lets assume your truck may see desert temps or use which could be compared to track use in some ways. For example at the end of the quarter mile on 10psi exhaust valves can easily see temps close 1600F. There limit is about 1550F. The headers can reduce this by 90-100 degrees keeping you safe. However craming your flow into a 3" would stifle that ability. I would recommend you run an x-pipe and dual 2.5 pipes as a minimum. ( For avoiding significant restriction from back pressure, the pipe should flow at least 2.2-2.5CFM per horsepower produced).


A straight pipe will flow ~115CFM per square inch of area (using inside diameter of the pipe). You are going to need between 1100-1400cfm as your flywheel hp could easily be 500-550.

A 2.5" diameter tube can flow a max of 608cfm. A 3'' can flow 975cfm. Heres the formula. The maximum that a straight piece of tube with a nicely tapered inlet and outlet (a venturi tube) can flow at 25" pressure drop is 138 CFM per square inch of cross sectional area. Flow follows a square root law so at 20.3" pressure drop that maximum will be 138 x sq rt (20.3 / 25) = 124 CFM per square inch.

A 2.5" diameter tube has a cross sectional area of 2.5 x 2.5 x pi / 4 = 4.9 square inches. The most it can therefore flow at 20.3" pressure drop is 4.9 x 124 = 608 CFM. Hopefully this will help you help you in your decision. You could always run dual 3" and dump themas planned. Just keep in mind no exhaust system is going to be 100% efficent due to bends and mufflers.

 

I do see what you are saying and makes perfect sense. Looks like I will trade it out for a 2-1/2" IN 2-1/2" OUT dual muffler. Just need to get a x pipe now and some tubing with new turn downs. I plan to keep the exhaust work as short as possible (dumped right at the start of the trucks bed) as I can not have the exhaust any where near the rear end when the suspension cycles. Thanks for the help.

It's going to be a long (4-8 week) wait...

 

Take a look at my pic albums. I have on for the exhaust. Perhaps u can get some ideas from it.

 

That is how I plan to run my setup...Just have turn downs at the end of the muffler..

 

Right answer, wrong formula. To determine the area of a circle, you would square the radius, not the diameter.