Water Injection into exhaust

[matoakley]

An unusual question.

I know water injection is used to cool induction charge in Turbos. I also have heard that it can be used to tune the apparent length of 2 stroke exhaust pipe to improve torque. It is also used to silence exhaust from space shuttle.

Could I inject water into exhaust of my 6.2 litre griff to reduce noise? How much would I need to inject and at what pressure?
Has any one done this?

Many thanks

Matthew

[alephnull]

matoakley said:

An unusual question.

It is also used to silence exhaust from space shuttle.

What flow-rate of hydrogen peroxide do you have on your Griff? I think about 4 tonnes/minute would do the trick, if it works for the Shuttle it will work for a Griff...



(Sorry)

[matoakley]

Thanks for that.

Yes perhaps a little unusual that why im asking. I have been struggling to silence LS3 griff and watched a program on the shuttle, hence brain wave

[eff eff]

Just how noisy is it?

[matoakley]

Depends who is measuring it. I think it is 104db at 4200, last two scrutineers said 108db(others have measured 103-5). More than 105 and I dont play! Already repacked silencer, and added cat etc. very little room available for more silencing

[Slow M]

Look at the Ultima forum for posts on sound pressure reduction.

B.

[Brummmie]

My 6.9ltr Cerbera measures 101db, i have two silencers behind the gearbox, and two under the boot floor.

[matoakley]

Thank you

Yes more silencers would be obveous solution but engine very low for handling so only one side pipe and that is as big as it can get. Have tried insert from Merlin but no improvement . Repacking very tightly helped a bit and I have designed some inserts that I will test Wednesday.
Water injection however sounds like a clever solution so may try to rig up a test!!

[Getragdogleg]

The quantities of water needed to keep the water injection system spraying for any length of time would rule out using it for more than a few minutes unless you wanted to build big water storage tanks in the car.

[matoakley]

I do shelsey in 32 secs, Loton in 59, Harewood 62 and noise testing takes 10 sec so may not need huge tank, but yes the volume required is the info required. Water spray is used to silence marine engines and so im led to believe the space shuttle.

Matthew

[eff eff]

Have a look at the Edelbrock SRT system

[Slow M]

http://www.popularhotrodding.com/enginemasters/art...
I plan to use this info for designing my system.

B.

[Jammie Dodger]

alephnull said:

What flow-rate of hydrogen peroxide do you have on your Griff?

Depends on whether he wants highlights or blonde all over

[marshalla]

matoakley said:

I do shelsey in 32 secs, Loton in 59, Harewood 62 and noise testing takes 10 sec so may not need huge tank, but yes the volume required is the info required. Water spray is used to silence marine engines and so im led to believe the space shuttle.

Matthew

You do know that the "silencing" on the shuttle is external, don't you ?

[Jammie Dodger]

Slow M said:

http://www.popularhotrodding.com/enginemasters/art...
I plan to use this info for designing my system.

B.

Thanks SlowM - i needed this as Jamie Rogers is rebuilding and improving my 5.0 chim + supercharger. He and I agreed what's the point if it's choked by a compromised exhaust

[Slow M]

Jammie Dodger said:

Thanks Slow M - i needed this as Jamie Rogers is rebuilding and improving my 5.0 chim + supercharger. He and I agreed what's the point if it's choked by a compromised exhaust

You're welcome, JD. I agree. The engine is one system, from the air filter (or air routing to it) to the exhaust tips, and should be designed as such. Too many treat the exhaust as an afterthought, with not enough attention to the science & technology behind it.
B

[domV8]

Jammie Dodger said:

alephnull said:

What flow-rate of hydrogen peroxide do you have on your Griff?

Depends on whether he wants highlights or blonde all over

The first relevant answer to that question