Testing my RIPP Supercharged Durango

Thunderhorse · Feb 26, 2017

Unless somehow your intake and exhaust valves are open at the same time headers aren't losing you any boost. Since the Hemi is an OHV and nobody makes a cam with lobes that would do that it ain't the issue.

Sounds like a tighter belt is in order, and a boostier pulley won't hurt

Reddragonwagon · Feb 27, 2017

So did you put the ripps on run it and then later install the headers?

If so what was your boost before the headers?

Also you can tell if you have e belt slip. Their will be belt dust on the pulleys.

If you have belt slip now with a 4" pulley then it's going to get worse with a smaller one.

Ammarov · Feb 28, 2017

Chase300 said:
Excellent, you're narrowing it down.
I do remember installing a whipple on a marine GM big block and after installing headers we too lost boost.
We had to install a smaller pulley to get the boost back up, but the upside was the engine made more power and the boat gained speed over the stock exhaust manifolds.
So if the belt isn't slipping you will be good to go soon.

i hope you're right, i bought the new pulley anyways, waiting to be shipped

Ammarov · Feb 28, 2017

Thunderhorse said:
Unless somehow your intake and exhaust valves are open at the same time headers aren't losing you any boost. Since the Hemi is an OHV and nobody makes a cam with lobes that would do that it ain't the issue.

Sounds like a tighter belt is in order, and a boostier pulley won't hurt

i tried to explain the same thing to my tuner, but he insisted

Ammarov · Feb 28, 2017

Reddragonwagon said:
So did you put the ripps on run it and then later install the headers?

If so what was your boost before the headers?

Also you can tell if you have e belt slip. Their will be belt dust on the pulleys.

If you have belt slip now with a 4" pulley then it's going to get worse with a smaller one.

I installed the headers and the supercharger at the same time.

I bought another belt that is compatible with the new pulley (3.25")

Thunderhorse · Mar 1, 2017

Ammarov said:
i tried to explain the same thing to my tuner, but he insisted

I...might not use him

Reddragonwagon · Mar 5, 2017

So a blower or super charger needs some sort of back pressure to build boost. iE the stock exhaust. Now when you add long tube headers or a better flowing exhaust you lose back pressure aka boost but the engine can breathe easier. To make up the 1-2 IBS boost lost you would go with a smaller pulley.

Belt slip is a problem that some super chargers fight and others don't. Easy way to tell is look for black belt dust.

Skippy426 · Mar 6, 2017

Reddragonwagon said:
So a blower or super charger needs some sort of back pressure to build boost. iE the stock exhaust. Now when you add long tube headers or a better flowing exhaust you lose back pressure aka boost but the engine can breathe easier. To make up the 1-2 IBS boost lost you would go with a smaller pulley.

Belt slip is a problem that some super chargers fight and others don't. Easy way to tell is look for black belt dust.

That's not how it works at all.... You're forcing more air into the cylinder when the intake valve opens. The exhaust valve is shut at that point. And it's not back pressure, it's exhaust scavenging. A properly designed exhaust will have no more than 2psi at absolute max of back pressure.

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Enginerd · Mar 6, 2017

Curious to see the results. Smaller pulley and some tuning from someone who knows what they are doing should have you impressed. Sounds like belt wrap on the ripp kit isn't great if it's slipping at 4psi.

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Reddragonwagon · Mar 6, 2017

[/QUOTE]
That's not how it works at all.... You're forcing more air into the cylinder when the intake valve opens. The exhaust valve is shut at that point. And it's not back pressure, it's exhaust scavenging. A properly designed exhaust will have no more than 2psi at absolute max of back pressure.

Yet in the same sentence you said it's not back pressure and it is. Wow good job there stud.
a blower needs some back pressure to help build boost. If you go with a free flowing exhaust then you have to spin it faster to make up for the loss.

That simple don't over complicate it.

Thunderhorse · Mar 6, 2017

That's not how it works at all.... You're forcing more air into the cylinder when the intake valve opens. The exhaust valve is shut at that point. And it's not back pressure, it's exhaust scavenging. A properly designed exhaust will have no more than 2psi at absolute max of back pressure.

Yet in the same sentence you said it's not back pressure and it is. Wow good job there stud.
a blower needs some back pressure to help build boost. If you go with a free flowing exhaust then you have to spin it faster to make up for the loss.

That simple don't over complicate it.[/QUOTE]

What? The supercharger builds up pressure against the exhaust valves which are closed at that point and return as much pressure as the blower puts into it. Exhaust scavenging is the exhaust system's ability to evacuate exhaust gases.

Skippy's right

Reddragonwagon · Mar 8, 2017

Why even try and help you people. You watch one fast and the Furious movie and you know it all. Yet you guys can't get a simple blower to work right on a SUV. I'll just keep my mouth shut and sit back. Next you will all be changing cams out to build more boost.

You guys can have this non sense.

Chase300 · Mar 8, 2017

Reddragonwagon is correct.
You will lose boost in a turbo car as well if you bolt on a much freer flowing exhaust system than say a stock system.
I would lose around 3 psi going from the stock 2 1/4 exhaust w/cat to a full 3" exhaust no cat on a turbo 4 banger.

These supercharger kits are designed for stock exhaust...you bolt on higher flowing exhaust system and you're going to lose boost.
Not saying you lose power...but boost will be lower.

Ammarov · Mar 8, 2017

I went today to another Tuner and had it tested before decide either to change the pulley or keep the 4".

in fact, he is the 5th guy to speak about back pressure but however, using HPTuner he managed to increase the boost to 6psi and get an output of 416awhp

we decided not to change the pulley as we expected the boost to exceed 13psi with the 3.25" one. this may break the engine as he already observed some knocks.

The back pressure is an existing factor that i have always said its not true ( since the valves are shut ). im not really good at mechanical physics, but the test done today shows its true.

ill be changing the pulley however in future but i want to make sure i can minimize the engine rpm to stay at the safe side.

Ammarov · Mar 8, 2017

6.508 psi to be specific

Chase300 · Mar 9, 2017

That's all good you found a tuner.

For those that think bolting on headers or a much better freer flowing exhaust or changing cams will not effect boost,
Here's a good read from Kennebell, a reputable supercharger manufacturer on low boost.
Note what it says that can cause low boost levels.

http://kennebell.net/KBWebsite/Common/pdfs/LowBoostCausesAndCures.pdf

Skippy426 · Mar 9, 2017

Chase300 said:
That's all good you found a tuner.

For those that think bolting on headers or a much better freer flowing exhaust or changing cams will not effect boost,
Here's a good read from Kennebell, a reputable supercharger manufacturer on low boost.
Note what it says that can cause low boost levels.

http://kennebell.net/KBWebsite/Common/pdfs/LowBoostCausesAndCures.pdf

I guess I kind of understand, thought that applied more to turbo's than superchargers lol.... I'll admit I was wrong haha

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FSTDANGO3 · Mar 9, 2017

Lets face we all are not perfect with this otherwise we would all be doing it for a living. The ideas of freeing exhaust up means you can add more on teh other end to make a Bigger Pump.
The concept of the engine just being a pump More in, More out within the max limitations of the motors insides.
An even smaller example is when someone buys a free flowing Corsa or Borla system yet sais I dont want to do teh cold air intake well if the physics of teh air intake dont allow for addittional air volume(and they wont with stock)Your shiny new exhaust just made you more NOISE and a Placebo hp gain. Now add an Intake that flows more air and the motor has the extra air it needs. Our cars are computer limited for emissions stds and Govt regulation to meet cafe ratings. So In order for the control to allow extra fuel and air to flow thru and add Ignition timing we need a tune.
If the pulley is changed to 3.5 or 3.75 it wont be 16lbs of boost. But it may be over 8 and that is risky especially if they are seeing knock already. As soon as teh knock sensors see that knock the timing will retard and the truck will detune itself to protect itself.
All the info here helps us to learn together no need to slander anyone or drive anyone out.
Now Red Wagon Cmon man we can all add unlimited nitrous and steering wheel buttons and outrun anything out there just like the movie...LOL
FF8 in movies April 14
Ya know your all going to see it!
STEVE

Chase300 · Mar 9, 2017

Skippy426 said:
I guess I kind of understand, thought that applied more to turbo's than superchargers lol.... I'll admit I was wrong haha

Sent from my SM

Trust me, if I hadn't seen it both in my turbo car and with a friend's Whipple marine engine after we added headers I would not have believed it. Even Dustin at Whipple told us headers would not make a difference over the stock exhaust manifolds...wrong. He learned too.

Ammarov · Mar 9, 2017

We all learn something new everyday.

Here's some teaser

Testing my RIPP Supercharged Durango

Thunderhorse

Reddragonwagon

Ammarov

Ammarov

Ammarov

Thunderhorse

Reddragonwagon

Skippy426

Enginerd

Reddragonwagon

Thunderhorse

Reddragonwagon

Chase300

Ammarov

Ammarov

Chase300

Skippy426

FSTDANGO3

Chase300

Ammarov

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