Roushcharger

[SilentScope]

pulley that bitch, you might see 8.5 psi out of it and get a killer chiller heat exchanger, it uses your AC to cool the charge temps wayyy down.
or get meth.

 

[stock05]

Thanks for the suggestions, all good. Now I just need to research a little.

 

[Mustang30212]

What pulley is on there? I know they make 9psi pulleys, an overdrive pulley will help, but beyond that I would just go with a good set of cams. Get the set you want for future mods you can get them installed and tuned for 1500.

I have the 2.57 blower pulley and the stock crank pulley right now and it makes 7lbs. I'm headed back to the dyno on Aug. 7th after the 10% overdrive installation. JDM says I should pick up 2.5-3lbs with it.

RH

 

[Mustang30212]

Man time flies...I"m JUUUUST heading to the dyno tomorrow...wish me luck.

RH

 

[JeremyH]

Good luck! Keep an eye on iats!

 

[Mustang30212]

Ok...results are in.

The car gained NOTHING with the 10% od crank pulley. No torque...no HP...NO boost. It didn't even change the curves in tq or hp.

Oh well...that's hot rodding...wasted money!! lol

RH

 

[JeremyH]

did it just created more heat, what were the iats at the end of the dyno run?

 

[Mustang30212]

The IAT's were fine....a little higher than with the stock balancer at the end of the run....but nothing out of line or anything to cause concern.

RH

 

[JeremyH]

The IAT's were fine....a little higher than with the stock balancer at the end of the run....but nothing out of line or anything to cause concern.

RH

might as well swap back then, recoup some money from selling it and mod else where.

 

[Riptide]

lol wtf?

How do you not pick up power with that OD pulley? Blower just max'd out?

 

[Mustang30212]

My thoughts exactly. No need to overdrive the blower if it's not doing any good. Plus...keep from wearing it out as quick.

Not sure on the "max'd out"...maybe with my current setup. My car is bone stock with the exception of the blower and a splice in x-pipe. Adding some headers and high flow cats might allow for more boost...if I'm thinking correctly.

Ya...anyone need an ALMOST new 10% o/d crank pulley? lol

RH

 

[JeremyH]

lol wtf?

How do you not pick up power with that OD pulley? Blower just max'd out?

Yeap, anything above 5psi on that blower is past it efficiency range, so with the smaller blower pulley ay 7-8psi its working it ass off and is def maxed out. Spinning it faster at this point is just gonna and heat and wear and tear.

 

[JeremyH]

My thoughts exactly. No need to overdrive the blower if it's not doing any good. Plus...keep from wearing it out as quick.

Not sure on the "max'd out"...maybe with my current setup. My car is bone stock with the exception of the blower and a splice in x-pipe. Adding some headers and high flow cats might allow for more boost...if I'm thinking correctly.

Ya...anyone need an ALMOST new 10% o/d crank pulley? lol

RH

The blower is maxed out, but you still have room to add some power, the longtubes and x will add some power but actually drop boost.

How much hp is it makin now?

 

[Mustang30212]

It made 409hp/386tq.

RH

 

[JeremyH]

It made 409hp/386tq.

RH

Not bad, probaly pick up another 20rwhp with longtubes and an o/r mid pipe. But you will see a drop in max boost from the less restrictive exhuast.

 

[Mustang30212]

Still doesn't explain whey we didn't see ANY increase in boost with the new pulley though.

RH

 

[JeremyH]

Still doesn't explain whey we didn't see ANY increase in boost with the new pulley though.

RH

That roots blowers have a very small/speciffic efficiencey range. Its rated to 5psi and works fine there. At 7-8psi with the smaller blower pulley, the blower is past its effiencey range and cant flow anymore air. So when you added the overdrive pulley and sped the blower up another 10% it was unable to move more air, its the physics of the matter, thats why you saw an increase in heat, it cant compress/move anymore air so its working against itself/the engine and the air on the other side of the rotors cant move out fast enough. (the blower size/displacement comes into play here as well).

Turn a vaccum or leaf blower on, now block the suction or discharge respectively, and that thing is going to heat up, similar concept.

On that note, with a full exhuast the engine will flow more air and the overdrive pulley might have made alittle more power on that setup.

 

[Greg Hazlett]

Concur; saw this on my 03 Cobra; added a 4lb lower pulley and gained 0 power as the blower was max'd out.

 

[EagleStroker]

Still doesn't explain whey we didn't see ANY increase in boost with the new pulley though.

RH

Call this an ignorant guess, but could it be without any other supporting mods the motor just can't get any more air in or out in it's current configuration?

 

[JeremyH]

Call this an ignorant guess, but could it be without any other supporting mods the motor just can't get any more air in or out in it's current configuration?