How to make a V8 sound good?

Grumpy75 · Post by **Grumpy75** » Tue Aug 11, 2015 7:43 pm

Hello everyone. I am looking at building a car with a V8 & need to know what I am letting myself in for. I have listened to thousands of V8's in drag cars and street rods.

I know how to get the power out of a motor but not how to get the sound that I want - and that matters, really really matters.

We all know that all V8's sound wonderful but some sound better than others. I know that size matters, I know that the lumpy sound comes from the camshaft but what is it that makes some V8's snarl when the throttle is blipped - generally competition motors - whilst others are soft/ woofly sounding even though not actually any quieter.

I am not naive enough to think that the total answer is one thing but where does that V8 snarl come from? Where do I concentrate my sound search efforts?

kiwicar · Post by **kiwicar** » Tue Aug 11, 2015 8:22 pm

hi
the biggest influence on the sound you are after is when the exhaust valve is opened, open it earlier and you get a sharper sound, open it later you get a softer sound. you get the "lumpy" tick over from a narrower lobe separation angle for a given cam duration giving more overlap (time when inlet and exhaust valves are open together. This is used by comp cams in their thumper range by a few other manufacturers, the basic combination for a given duration is to make the exhaust timing about 12 to 14 degrees more than the inlet, use an LSA of about 106 to 108 degrees and time it about 2 degrees advanced.
best regards
Mike

Grumpy75 · Post by **Grumpy75** » Sat Aug 15, 2015 2:42 pm

Thank you for that. I must now decide on a camshaft that works but doesn't destroy what little mpg I would otherwise get.

PS Is it just me or is this site so slow as to almost unusable. I am on Fibre Broadband & it is taking several minutes to load each page. I haven't replied for several days because I thought that there must be a problem. Windows 10 & Edge browser.

unstable load · Post by **unstable load** » Sat Aug 15, 2015 5:15 pm

Grumpy75 wrote:PS Is it just me or is this site so slow as to almost unusable. I am on Fibre Broadband & it is taking several minutes to load each page. I haven't replied for several days because I thought that there must be a problem. Windows 10 & Edge browser.

Dead slow on my side, too. I thought it was the Nigerian rainy season messing the network up, but apparently it's not just me.
Windoze XP, Firefox.

Post by **Coops** » Sat Aug 15, 2015 5:53 pm

issues in the USA server,
have been trying to get it sorted since Thursday,
sorry its slow but at least its still online unlike previous times

Ian Anderson · Post by **Ian Anderson** » Sat Aug 15, 2015 9:19 pm

Mike knows his stuff, but I believe he sound comes down to getting everything right and in balance, so you get induction, engine and exhaust noise in harmony.
In a normal V8 the exhaust pulses ate not even side to side so the exhaist note is, in my opinion not nice.

Now correct the exhaust note by combining the correct pipes and you get something that sounds exotic

This is near perfection to my ears

Ian

Devonrod · Post by **Devonrod** » Sun Aug 16, 2015 2:18 pm

A V8 sounds better with a balance pipe.

ChrisJC · Post by **ChrisJC** » Sun Aug 16, 2015 4:34 pm

There are a ton of factors.

I would listen out for something you like the sounds of, then copy it, at least copying:
- Engine make / size / fuelling / ignition.
- Exhaust manifolds
- Exhaust pipe size / configuration / length / silencers.

Chris.

gelmonkey · Post by **gelmonkey** » Sun Aug 16, 2015 7:32 pm

The replies you have already got are all sound advice pun intended however if you want a real nasty sound on the odd occasion then put some electronic cut outs in your exhaust system and open them as and when you want .
I speak from knowledge of having some in my system and it never fails to put a schoolboy grin on my face.

Cheers
P

Mark · Post by **Mark** » Sun Aug 16, 2015 8:16 pm

I want this sound

From a small block Ford if that's possible !

unstable load · Post by **unstable load** » Mon Aug 17, 2015 4:27 am

Coops wrote:issues in the USA server,
have been trying to get it sorted since Thursday,
sorry its slow but at least its still online unlike previous times

Cheers, Coop! It's much better this morning.

DaveEFI · Post by **DaveEFI** » Mon Aug 17, 2015 8:18 am

gelmonkey wrote:The replies you have already got are all sound advice pun intended however if you want a real nasty sound on the odd occasion then put some electronic cut outs in your exhaust system and open them as and when you want .
I speak from knowledge of having some in my system and it never fails to put a schoolboy grin on my face.

Cheers
P

Interesting. I have a Rimmer SS sports system on my SD1 which sounds very good - but is too loud at cruise on a motorway. Gets a bit wearing. Would be nice to throw a switch or whatever to make it quieter. I'd guest a restricter valve of some sort would help? Who sells such things?

kiwicar · Post by **kiwicar** » Mon Aug 17, 2015 10:34 am

Mark wrote:I want this sound

From a small block Ford if that's possible !

Hi Mark
that may be tricky on a SBF as the sound used on that track comes from a blown hemi on methanol and open pipes, you could change around the firing order, sort out the exhaust and methanol is only 49p a litre if you buy it 2 barrels at a time but it may be a bit of a handful in tescos car-park

best regards
Mike

Mark · Post by **Mark** » Mon Aug 17, 2015 7:32 pm

kiwicar wrote:
Mark wrote:I want this sound

From a small block Ford if that's possible !
Hi Mark
that may be tricky on a SBF as the sound used on that track comes from a blown hemi on methanol and open pipes, you could change around the firing order, sort out the exhaust and methanol is only 49p a litre if you buy it 2 barrels at a time but it may be a bit of a handful in tescos car-park
best regards
Mike

Damn !

Never mind, was the actual car a blown hemi or was it dubbed ?

kiwicar · Post by **kiwicar** » Mon Aug 17, 2015 8:29 pm

Hi MarK
no from what I remember it was a nearly stock SBF! I know the engine sound was dubbed onto the video. I saw the car arrive slung under a helicopter at Donnington park when they toured when Eliminator was out.
best regards
Mike