Keeping Throttle Bodies Quiet

[M_R_205 5 1 Cars]

as part of my XS16v build im going to be fitting a set of throttle bodies, and if there anything like the carbs im running now i assume there going to be loud, as the car is going to be a sleeper i want it to be rather discrete and quiet,, if i were to fit the trumpets into a box and duct to an air box will that keep thing nice and quiet? or am i going to have to be a little more creative?

 

any advice welcome

Cheers

Paul.

Edited June 10, 2009 by M_R_205

[EdCherry 34 1 Cars]

Sound deaden your bonnet or stuff your trumpets with paper

 

Enjoy the noise mate

[welshpug 1,661]

keep off the loud pedal

 

depends how long a trumpet you intend to fit to the inlet you pictured, that'll effect what you can fit in there.

[Liquid_106 97 1 Cars]

Could try something like this?:

 

 

 

Needed to quite down the TBs to pass trackday noise regs - think it was made from 1 or 2mm steel but could use alu to make it lighter.

Ignore the tumble-dryer ducting tho, just a 'mock up'

Edited June 10, 2009 by Liquid_106

[Rippthrough 98]

A plastic airbox - aluminium just does have the dampening effect needed to quell the intake noise.

[sideways danny 0]

an airbox will help, there's quite a few options readily available, Jenvey/Piper etc.

 

Be aware that the distance from the end of the trumpets to the box is important. Baffle plates can make a big difference to torque

[M_R_205 5 1 Cars]

Wht liquid 106 has there looks exactley like what i was thinking! Did that set up make much difference to BHP?

 

I can make a trumpet box out of alu easily enough but plastic will be a little harder... i can easily just fit a standard air box to house the filter some where.

[richsmells 2]

I've seen plastic ones for sale but they're £££. However, if they're well tested and designed then probably worth the cost. Not as much fun as making your own though:

 

http://www.eliseparts.com/products.php?product=309

Edited June 11, 2009 by richsmells

[bales 1]

I don't really get it, I am assuming it has nothing to do with noise regs anywhere so you purely want to get rid of the noise so its a sleeper.

 

So let me get this straight, you want to deprive yourself of the awesome sound of throttle bodies not beacuse they are too loud or give you a headache but because if you happen to race anyone they are going to think 'bloody hell thats quick but it doesnt sound anything special'.....or that you have the element of suprise because people will expect your car to be slower than it is due to its induction note...

 

Is that genuinely the reason, if I was going to shell out for t/b's the noise would be one of the main reasons.

 

Anyway its obviously your choice but I can't say I understand the reasoning behind it, are you that bothered about how people percieve your car?

[welshpug 1,661]

Depends on the state of tune of your car, but many XU's have been known to be very close, quite a few have been over noise limits on induction noise....

 

Similarly TU's, though they are somewhat muted a little from outside due to their position,

 

 

Then imagine Honda....

Edited June 11, 2009 by welshpug

[bales 1]

Depends on the state of tune of your car, but some XU's have been known to be very close to noise limits on induction noise....

 

 

Then imagine Honda....

 

I completely agree, lot of bike engined cars are actually louder induction than exhaust, but he has said it is because the car is to be a sleeper not anything to do with passing noise regs.

 

Thats the only reason I am saying it really, and tbh i'm not being very helpful is that I just don't get the whole 'sleeper' thing, I can understand the fun factor of having something that looks crap and is fast but just not removing an aspect of a car that to me would be one of the best things about it just so that you can 'suprise' someone....

 

Regarding Honda's my CTR is ridiculously loud when it comes on Vtec with an open filter, it honestly sounds like it is on throttle bodies, never heard any car on a plenum like it!

[Saveit 0]

Who would want to quiet down a set of throttle bodies The sound is awesome!

Edited June 11, 2009 by Saveit

[andychalmers 0]

My 205 with standard S16 engine & jenvey bodies sound awsome but loud on full chat. Louder than most cars on bodies. I've put links to a couple of video clips

 

 

[taylorspug 7]

any advice welcome

Cheers

Paul.

 

Er, dont start the car, dead quiet then!

 

In all seriousness an airbox/plenum chamber will do a good job. My mate Tom has one on his Vtec Mini and it does dampen the tb noise down significantly.

[Batfink 201]

seriously at low revs all you have is a nice growl. No-one really notices until you floor the loud pedal and the birds drop out the tree's in fright...

[kate205gti 4]

^^ agreed mine was quiet sedate parking and pootling round town, till you went over 4.5k then it let rip

 

but the whole point of throttle bodies IS the noise - there is no other reason :P let them rip and enjoy it

[SurGie 54]

Who would want to quiet down a set of throttle bodies The sound is awesome!

 

I agree, the sound is bloody good, much better than having more speed from a turbo for instance

Though if i had the money i would have another 205 with a SC for the extra speed.

[Saveit 0]

Yeah. Im in the middle of building two different engines (one with Xu10 head and webers and a endurance race engine 1.6 180bhp'ish) but the next engine ill build will be with a turbo for the extra power. But nothing beats a set of TB's with regards to sound.

[welshpug 1,661]

Can't remember who's car this is so I hope they don't mind me posting it up, I think it sounds ace

 

 

[Saveit 0]

Can't remember who's car this is so I hope they don't mind me posting it up, I think it sounds ace

 

 

 

dj_mini i think? (think thats his name on here)

[taylorspug 7]

Thats Sams old TU-engined Rallye from back in the day, few years old that video!

[welshpug 1,661]

its a few years old now I think, Sandy might have had something to do with it is all I can remember!

[M_R_205 5 1 Cars]

I know its stupid wanting to keep them quiet but if the MI is going to be like my current 8v then even at low revs 1250 - 3000 its just a little to much, raising your voice to talk, turning the cd player up just to hear the lyrics, and then when your on a longish trip, say to shefield its 2 hours (maybe an hour and a half ) of constant ear attack, i dont mind it being loud at full chat, infact i love that! jusrt want it quite under say 4K,

 

The exhaust im making for it is also being built with volume not performance in mind and so has 2enormeous boxes being fitted to it,

 

To be honnest i think it may be a good idea to try the car first and see what its like and go from there

 

Paul.

[Mongo 0]

I know its stupid wanting to keep them quiet but if the MI is going to be like my current 8v then even at low revs 1250 - 3000 its just a little to much, raising your voice to talk, turning the cd player up just to hear the lyrics, and then when your on a longish trip, say to shefield its 2 hours (maybe an hour and a half ) of constant ear attack, i dont mind it being loud at full chat, infact i love that! jusrt want it quite under say 4K,

 

The exhaust im making for it is also being built with volume not performance in mind and so has 2enormeous boxes being fitted to it,

 

To be honnest i think it may be a good idea to try the car first and see what its like and go from there

 

Paul.

 

 

You should be fine below 4k, constant or below. Its just when you press the pedal down to the floor at full chat you will hear it. I thought mine was going to be an issue so i bought a pipercross airbox with inline filter:

 

 

But i have longer trumpets (only takes up to 45mm trumpets) and i liked the induction noise so its sat in the box. Im fairly sure you will enjoy the noise with filter(s) though....

[Sam 4]

Yep tbh the noise is almost directly proportional to throttle load. The best sound is low rpm full throttle though by far.

 

Can't remember who's car this is so I hope they don't mind me posting it up, I think it sounds ace

 

 

 

Thanks. Yep that was mine, but that video was pre Sandy fettling! After he got his mitts on it - it was much much better. We fitted the newer bodies and gave it a map. Shame I never got it on the rollers, never felt the need to.

 

 

I miss that car

 

edit: Sandy was driving!

Edited June 14, 2009 by Sam