Bumper exit exhaust questions

[SupremeDsm]

Ok so I think im going to run the exhaist for my gsx out of the front bumper but I got a few concerns. Do I need any type of vacuum system to relieve any pressure off the block? And what about back pressure? What all should I.do to run that exhaust safely? Thanks.

 

[knochgoon24]

Running your exhaust through the front bumper is illegal, but you probably already knew that.

You're turbo provides all the back pressure you'd ever "need." (Which you don't.)

And what's with this vacuum system you talk about? Relieving pressure on the block?

 

[Bud92gsx]

A turbo exhaust thrives on 0 back pressure..The more free flowing the uxhaust the better it works..

Ever seen a deisel truck with a 4 inch exhuast or a semi with a 10 inch stack..That's to have the most free flowing exhaust..

 

[SupremeDsm]

Ya there is no emissions where I live. Sweet and yes a vacuum system to.relieve.pressure off the pistons. I just wanna run this cause its sexy.

 

[Bud92gsx]

There are no emmisions, but you still know it's ilegal right..Any mods to exhaust are ilegal in all 50 states I beleive...

Then again some cops might not bother you, then there are the dicks..Who will pull you over for anything..

 

[JAX2Ganey]

Ya there is no emissions where I live. Sweet and yes a vacuum system to.relieve.pressure off the pistons. I just wanna run this cause its sexy.

Im curious about this, 'relieving pressure off of the pistons' concept.

 

[Bud92gsx]

You releive crankcase pressure with the pcv valve..Releiving pressure off the piston is something new to me...

 

[TSI from Hell]

Never heard of releasing pressure off the pistons also... Mind elaborating on that OP?

 

[DSM_munky_man]

Im curious about this, 'relieving pressure off of the pistons' concept.

You releive crankcase pressure with the pcv valve..Releiving pressure off the piston is something new to me...

I am curious too as to what this means? you need the pressure on the piston to push it down to create power...OP Do you even know how an engine works?

 

[Bud92gsx]

I'm not sure if that's torwards me..But you do know that the pcv valve helps you not blow your dipstick out and so forth right..

 

[DSM_munky_man]

No bud, the engine question was for the OP. I was just trying to quote your "relieveing pressure" thing.

 

[Bud92gsx]

Ohh you were quoting me, to ask him if that's what he meant..Gotcha..

Damm I thought I was having one of those retarded days again..

 

[tsi209]

Are you talking about jakebrakes that the big rigs use to slow down?

 

[Bud92gsx]

A jakebrake cuts power to half of the cylinders to slown down quickly..Where you would just downshift..Or slam on the brakes..

 

[TSI from Hell]

I'm assuming that there's no such things as "relieving pressure off the pistons" . Not in our engines anyways. But, I could be wrong...

 

[DSM_munky_man]

A jakebrake cuts power to half of the cylinders to slown down quickly..Where you would just downshift..Or slam on the brakes..

Theres many different ways, cut injectors, some hold open exhaust valves, the mercedes one has its own special valve it opens, works like the open exhaust valves, but is its own seperate valve only used for jake brake application. But essentially yes its cutting power to cylinders, some cut 2, 4 or all 6 cylinders too, depending on setting or need

 

[Bud92gsx]

So it's one of those manufacture things..Certain companies do different things, but it works the same way?

 

[jtmcinder]

I think the OP is talking about crankcase ventilation via a venturi in the exhaust. Rather old school, but some like it because you get positive ventilation (unlike a mere catch can) while preventing oil from getting into the intake (unlike the stock set up). Also emissions-illegal, but if he's running his exhaust out the front bumper, then it's relatively minor.

 

[3kgt2nv]

so wait i just drilled holes in my pistons to relieve pressure for nothing?

 

[GSX401]

Basically it's like having a turbine fan inside a larger chamber built in between and inlet and the actual exhaust outlet (think muffler). As the exhaust his the fan and spins it, it creates a vacuum that pulls the exhaust out of the hotside faster than it would if it was just to free flow. This helps to create a cleaner burn.

It's very common in bikes (Harleys not sport bikes) and trucks, I also imagine open wheel race car leagues find these very common as well.

 

[99gst_racer]

I think the OP is talking about crankcase ventilation via a venturi in the exhaust. Rather old school, but some like it because you get positive ventilation (unlike a mere catch can) while preventing oil from getting into the intake (unlike the stock set up). Also emissions-illegal, but if he's running his exhaust out the front bumper, then it's relatively minor.

This is what I gathered as well. Although the exhaust systems on these cars have proven to not be useful for such a crankcase ventilation configuration.

 

[jtmcinder]

That's because most people run exhausts that are rather big, which reduces the velocity too much for the venturi to be effective. When people run venturi venting on V8s, they have the exhaust velocity from the head, because they don't have a turbo. In general, venturi venting isn't often successful on turbos, although it was the "in thing" for a while in the Supra world.

 

[DSM_munky_man]

So it's one of those manufacture things..Certain companies do different things, but it works the same way?

Basically, technically only cummins are Jake brakes too, every manufacturer has there own, so cats, Mercedes, international all have differed names but they all do the same thing, relieve compression, thus slowing down the engine.

The venturi vent is super old school ain't it? I was just learning bout it the other day. Maybe he is thinking something like scavenging, but with anything positive pressure (aka boost) it's null anyway cause overlap should be reduced or low enough that it won't matter.