Presumably this is too loud for IVA?
Presumably this is too loud for IVA?
The Gp4 version would be too loud for IVA for sure, the single exit version no problem.
This one passed IVA yesterday at 97.9dB at a genuine 4500rpm running with a 3.2Gta motor on a stock ECU. Exactly the same silencers as the Gp4 exhaust shown earlier, the difference being that this one is fitted with the phase 3 catalysed exhaust manifolds which go a long way to suppressing the noise.
Last edited by Strat Fan; 31-08-2017 at 21:11.
"You can lead a horse to water, but a pencil must be lead"
Stan Laurel
Nice reg. Craig.
I saw V600 STR a few months back on the DVLC web-site and was going to buy it but unfortunately didnt - I understand it was then bought by someone else on the forum (not sure who )
Love the colour too - cant wait for my body panels !!
Peter
Finally got to fit the stainless steel system I've been working on yesterday. Planning started months ago, the bits have been gathering dust for a couple of months.
It is still a very quiet (neighbour friendly) system, just a little more base tone, and a smidgen louder. Feels like it pulls a little better too.
Last edited by Griff; 17-09-2017 at 08:48.
Nice!
Strange its still "quiet". Maybe the manifolding contributes some muffling. Is it possible to play with the box stuffing?
Tim, no I don't think the manifolds are a factor, plenty of others use them in systems that are more audible than mine, as far as the box is concerned 'take it or leave it' are the options, no packing or repacking of the box is possible.
The quieter Stratos systems that I have seen/heard on cars regardless of chassis manufacturer tend to be transverse, and none straight through.
Mine being transverse, and one in, two out ticks all those boxes. The box itself is the biggest I could get with clearance between the chassis legs, on the basis that I'm maximising the possible silencing.
Funnily in its (silencer) original four cylinder turbo application the noise is both crisp and fruity, traits which are still evident in my application but not to the same degree.
I think the manifolds merging before passing through a common silencer may also be a factor, with the exhaust pulses from one bank being damped by the pulses from the other bank?
So in effect I'm trading ultimate efficiency for noise suppression. That said the old system was quite restrictive with very small pipe diameters, so the new system is still an improvement.
If my supposition is correct straight through single banked exhaust systems will ultimately always be more efficient, and in consequence (possibly) noisier, but I'm surmising.
Last edited by Griff; 26-11-2017 at 21:42.
Here is a slightly different design, Lance from OJZ Engineering built it, Zircotec coated it and Guy Croft Racing specified the tube sizes and lengths. The headers are all the same length and the tube diameter increases after the collector and at the entry to the silencers. The two 120mm diameter silencers enable me to have the longest possible pipe and meet track day noise limits.
It does sound really nice with twin DCOE45's although it is obviously not a V6.....
I must try to fit my GoPro to the rear clam to capture the sound.
Seems like there is a garage day recently in Germany !!
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