Exhaust Tuning with SC

topcatcustom · Post by **topcatcustom** » Thu Oct 23, 2008 2:59 pm

Is it important with a SC? I know its not with turbo's but that is a different thing all together...

sidecar · Post by **sidecar** » Thu Oct 23, 2008 3:43 pm

topcatproduction wrote:Is it important with a SC? I know its not with turbo's but that is a different thing all together...

Just my opinion and all that but I would have thought that the tuned lengths etc are not very important, quite often exhaust tuning is referred to as "harmonic supercharging"....well you are doing that with a bloody great compressor.

I guess that the exhaust still needs to flow well so you don't want to fit pea shooter sized headers with nasty sharp bends etc.

Infact turbo charging can benefit from the lengths being correct, you can get positive and negative standing pressure waves in the exhaust, if a postive standing wave is right where the turbo is then it will "see" a higher exhaust pressure. AJMHO!

Pete

JP. · Post by **JP.** » Thu Oct 23, 2008 4:16 pm

Supercharged engines do not like backpressure. Its very simple. If you are pumping greater quantity of air into the engine on the intake side, you've got a greater quantity that has to get out the exhaust side and yuo don't want the plumbing back up.

A supercharged engine picks up significant power when its uncorked.

Headers, extra big very big bore tubing and freeflow muflers will deffo help.

I run a 3" double system with a balance pipe and Hooker Aerochamber mufflers.

topcatcustom · Post by **topcatcustom** » Thu Oct 23, 2008 4:59 pm

Thanks both of you- good points!

Well it would be nice to run 3" stainless tubes straight out the sides then.... if I can find some long thin silencers that will fit under the mx5 sills

...may be some cutting involved...

As far as headers/manifolds go I need to find some big bore 4-1's (?) I dont know whether to make them up myself or not- I am a fabricator but to bend thin wall erw/stainless you need a pretty good mandrel bender methinks

expensive

JP. · Post by **JP.** » Thu Oct 23, 2008 5:52 pm

I'll have the standard SD1 cast headers 4 into 2 into 1 design cause there wasn't much else that would fit..........in a left hand drive Capri mk1.

Stay away from Cherry Bomb design Mufflers or similar design Glasspack mufflers

As they create only a nice sound but very unwanted backpressure also. The louvres causes the gasses to stop flowing along the side of the inner tube and the stopped flowing gas is creating a huge restriction for the fresh exhaust gas that enters the muffler.

Here's a hint.....with very usefull information ISBN 1884089291 infact every information you'll need.

topcatcustom · Post by **topcatcustom** » Thu Oct 23, 2008 6:58 pm

Ha got it! Not had time to read through it all yet though, any tips on best mufflers? Dont really have space for the side by side thick ones...

stevieturbo · Post by **stevieturbo** » Thu Oct 23, 2008 10:02 pm

Magnaflow make some very good stuff....

just make sure the system is smooth, and free flowing, and it will be fine.

topcatcustom · Post by **topcatcustom** » Fri Oct 24, 2008 10:40 am

Might go Dodge Viper style with them

man I love those things!!!!

kiwicar · Post by **kiwicar** » Fri Oct 24, 2008 3:00 pm

I bought a load of mandrel bends off OJZ, they do them in a selection of sizes and bends up to 180 deg (ish), the legs are generally long enough to minimise welding too many sections together.
Mike

topcatcustom · Post by **topcatcustom** » Fri Oct 24, 2008 3:08 pm

kiwicar wrote:I bought a load of mandrel bends off OJZ, they do them in a selection of sizes and bends up to 180 deg (ish), the legs are generally long enough to minimise welding too many sections together.
Mike

Sounds good, I may make up a stainless one with a nice fat bore, or mild steel and ceramic coat it..? Heard a lot of bad things about exhaust wrap in road car set-ups... and seen a Aston V8 with white ceramic coated headers- b-e-a-utiful!!!!!

chodjinn · Post by **chodjinn** » Tue Oct 28, 2008 4:25 pm

Yeah ceramic is the way forward. I ripped off the exhaust wrap from my cast iron headers, and not before time to, took me best part of a day to clean and restore them due to the rust!

topcatcustom · Post by **topcatcustom** » Tue Oct 28, 2008 5:17 pm

I supposse track cars get away with wrap due to being used so little and being kept in nice warm garages!!! With regards to the cherry bombs, if I remember can you use them either way round depending on what you want it to sound like... meaning the louvres could face away from the engine giving better flow... But just remembered cherry bombs are a bit chav and are just made for the loudest noise possible!!!

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Exhaust Tuning with SC

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