[Shaun03GT]

Not only the torque, but your rwhp will be higher in the lower RPM's. This is something that really needs to be tested out vs calculating numbers. So many different things affect it.

What I would like to see, is Tom, pulley it for say 16psi. Bleed off at 9-10psi. Compare the dyno sheets, then compare slips from the track.

[MustangMatt96GT]

Originally Posted by Shaun03GT How much heat are you talking? Oh you wouldn't know because u haven't done it. The gains down low til your wastegate opens would be far far better then losing alittle power up tip because of the heat. Centris don't even run that hot. I'm running a 2.87 pulley and heat isn't affecting me that much.

Thats great.... Tell me what I do and dont know.... Let set this straight.

What is the measure of boost? Its not the volume of air going in a motor, its not the speed the air is going in the motor.... its the RESISTANCE that motor has to extra air. Put a restrictive exhaust on a car and you'll make more boost, but make less power... Same thought process with the intercoolers... lets intercool make less boost but make more power (cooler air charge)

So now lets take a centri car pullied for 12 PSI. (I don't have real numbers in front of me, so these are made up). IATS are fine, and it makes 400 HP at 5800 RPM.

Now lets take that same motor, pulley it for 20 psi (most the blowers on stock motors, aren't even capable of that amount of boost). So now we have a much much higher resistance of how much the motor can take in air wise. Think of electricity in the instance (been working on circuits homework, so its in my mind). The more resistance, the hotter the wire gets right, thus why there are bigger (smaller gauge) wires. So now we are running more boost (higher resistance) on the same engine (gauge wire) its going to make more heat.

We have tried this with more than once car, a 393 cubic inch small block with a really nice set of heads (300 plus CFM at .650" liftm right where the cam is)and a Procharger D3. Pullied it for 12 PSI and put a boost controller on it at 8 psi( electronic waste gate). It went 3 tenths slower and 4 MPH slower than when its pullied for 8 at 6800 RPM. That is just one example.

I will tell you this.... If you want me to make the numbers work and show you the equations, I have more than enough resources to prove to you its not worth it. You cannot disprove the laws of thermodynamics and fluid dynamics.

[40thAnnivGT]

Anywho, thats on a Mustang Dyno if it matters.

[Eagle2000GT]

My car was originally tuned on a Mustang Dyno. The Dynojets its been on since have shown lower or equal numbers. I do not know why people say a Mustang Dyno reads lower.

[Shaun03GT]

Originally Posted by MustangMatt96GT Thats great.... Tell me what I do and dont know.... Let set this straight. What is the measure of boost? Its not the volume of air going in a motor, its not the speed the air is going in the motor.... its the RESISTANCE that motor has to extra air. Put a restrictive exhaust on a car and you'll make more boost, but make less power... Same thought process with the intercoolers... lets intercool make less boost but make more power (cooler air charge) So now lets take a centri car pullied for 12 PSI. (I don't have real numbers in front of me, so these are made up). IATS are fine, and it makes 400 HP at 5800 RPM. Now lets take that same motor, pulley it for 20 psi (most the blowers on stock motors, aren't even capable of that amount of boost). So now we have a much much higher resistance of how much the motor can take in air wise. Think of electricity in the instance (been working on circuits homework, so its in my mind). The more resistance, the hotter the wire gets right, thus why there are bigger (smaller gauge) wires. So now we are running more boost (higher resistance) on the same engine (gauge wire) its going to make more heat. We have tried this with more than once car, a 393 cubic inch small block with a really nice set of heads (300 plus CFM at .650" liftm right where the cam is)and a Procharger D3. Pullied it for 12 PSI and put a boost controller on it at 8 psi( electronic waste gate). It went 3 tenths slower and 4 MPH slower than when its pullied for 8 at 6800 RPM. That is just one example. I will tell you this.... If you want me to make the numbers work and show you the equations, I have more than enough resources to prove to you its not worth it. You cannot disprove the laws of thermodynamics and fluid dynamics.

Thats cool man. But Im just saying, your over exacturating on the whole making heat thing. Like I said, Im at a 2.87 pulley, and Im still below the blowers max RPM, and Im not having any issues with that. If I put a powerpipe on, and a better intercooler, I could hit 15-16psi with it. Now if I set the wastegate at 10psi, Im only going to see gains in the midrange, and it might lose alittle power up top, but nothing to drastic.

We just need someone to do this. An entry level blower on one of these cars. I know people do it with bigger models, like F1C, and YSi's, I think even D1SC people do it.

[Eagle2000GT]

Originally Posted by MustangMatt96GT Now lets take that same motor, pulley it for 20 psi (most the blowers on stock motors, aren't even capable of that amount of boost). So now we have a much much higher resistance of how much the motor can take in air wise. Think of electricity in the instance (been working on circuits homework, so its in my mind). The more resistance, the hotter the wire gets right, thus why there are bigger (smaller gauge) wires. So now we are running more boost (higher resistance) on the same engine (gauge wire) its going to make more heat. We have tried this with more than once car, a 393 cubic inch small block with a really nice set of heads (300 plus CFM at .650" liftm right where the cam is)and a Procharger D3. Pullied it for 12 PSI and put a boost controller on it at 8 psi( electronic waste gate). It went 3 tenths slower and 4 MPH slower than when its pullied for 8 at 6800 RPM. That is just one example.

I was going to argue with you on the first paragraph. There is no additional resistance going into the motor. It being bled off to atmosphere. But I can't argue with the second paragraph. Now I'm trying to understand why... I don't believe heat is the total explanation. If you shift to the next gear and hit higher horsepower/torque but it stops pulling because of the boost limiter(which is exactly what it would do) would that lead to slower times?

This is something to ponder... but I've not given up entirely on the idea but it is something to ponder. What other motors have you tired this with?

[Shaun03GT]

Exactly, rather then dropping to say 5psi, youd be at 10psi already....idk I really think this is just something that has to be done.

[MustangMatt96GT]

Well I hope you guys get the results you want. But on my EFI renegade setup on my car... its only pullied with a 3.25 top and a 8 inch crank. just idling gets warmer than you want to touch the blower or the discharge tubes. I am not intercooled, but its pullied for around 17 PSI at sealevel, it makes 12 psi at this altitiude...

Also at this altitude I have been told by procharger directly on that same D3 on my firends car that we can spin it higher than recommened because we dont compress as much air with the less pressure. We have been 20000 rpm faster than recommeneded on that blower, and its amazing. how much it richens up because of the less dense air charger (this was before we did a back seat intercooler).
Good luck guys I hope you get the results you want, but at the track (all I care about, the street it makes way to much power to do anything) it will mostlikey be slower with the same varaibles.

[Eagle2000GT]

Thanks for all the information. I'm going to pass on this. The anticipated gains are small, there are known drawbacks with small pulleys and it has apparently failed to improve performance on other motors.

Thans again for the information. That's the great thing about Modded Mustangs. We can exchange ideas and learn from what others have tried.