Noisy exhaust Griff 500

[jackg]

Hi All

I've just bought a Griff 500se. It is very much a fine weather toy so I thought I'd release the inner beast.

Fernhurst did the back box sleeve so it sounds ok but I'd like more and maybe a bit more power/throttle response.

My question is, do I go for a Y pipe and decatted manifold or a full system and which is the best to go for?
Also, will I need to remap it and again who would do that?

Fimally, any easy tweaks to get more power?

Really finally, suspension a bit soft, what do you recommend for fast road?

Many thanks

Jack

[SILICONEKID340HP]

I have the ACT Y piece and pre cats out,sounds awsome but you do get some clatter from the engine bay.Motor way driving is a pain because the drone from the back gets on your nerves.I had a exhaust conversion at one point ,copy of the ACT sports exhaust with main cat in pre cats out ,this gave a crisp raspy noise with no engine bay clatter and silent on the motorway until you tweak the throttle.I think the sleeved system is a no no sounds a bit agricultural.Reason i changed is the main cat was blocked then i found the combination of the ACT Y piece and sports exhaust was just to much..This was my conversion and best sound in my opinion..Two hand made cherry bombs ,perforated pipe stainless steal pipe and wadding, throw away the silencer box.second picture is the ACT sports exhaust both sound awsome.For a quick fix you could stick these track day silencers in and leave them..Mine seems to idle and run a lot better with them fitted and they look prity smart secured with a self tapper.
http://tvrmonster.com/store/index.php?act=viewProd...



I use the push in type track day silencers for long trips ..This is the sound with the silencers..still sounds nice.95db with silencers 105db with out..Turn the volume up !
http://www.youtube.com/watch?v=gDGQt2zNyC4&NR=...
http://www.youtube.com/watch?v=l3MVMuVQuqg&fea...
http://www.youtube.com/watch?v=7es8pYdJrVU&NR=...

Edited by SILICONEKID340HP on Thursday 16th June 12:17

[Mr MoJo]

Get yourself along to The Growl and listen to a few. I'm currently running straight through exhaust with precats out, plenty loud enough !!

Welcome to the SE club by the way

Eta, have a look at my profile for some subtle mods. I decided to stay quite tame compared to some, but it has transformed the way the car performs. Revs alot better than as standard and pulls throughout the rev range.

Very happy with what I've achieved but I'm sure there's more to come in the future !!

Edited by Mr MoJo on Thursday 16th June 21:21

[clive f]

I`d remove the pre cats first, if not already done, also best to have some cones welded into the empty precat area, this helps to stop the noisyness often associated with removing precats, and it can sound a bit tiny with 4 primaries finishing into an empty 4" diameter pipe, the pipe was only made that big to house the cats anyway.


after that drive the car around for a bit and decide if you want it any louder before going further.

[spend]

clive f said:

..the pipe was only made that big to house the cats anyway...

I'm not convinced that's totally right Cliff. There are quite a few Nascar collectors where they merge 4 into a big st off pipe and then step it down after a decent run of the thick bit. I'll agree it doesn't look right but they must do it for pure performance (flow) reasons in Nascar?

[Hoover.]

look at per cat assembly, and then just see how big the pipes are... 500's are for girls

[clive f]

but my dear david, he doesn`t have a nascar, its a bloody griff!




you do realise me and the mrs spent an hour walking around the car park at chatsworth after being told you were there, but you must have left when you saw us coming!

[spend]

Sorry about that old chap, it was too embarrassing (even for me) having a "screamer" in the car with so many people about at Chatsworth.

I only managed 10mins duration & probably 3 mins uninterrupted conversation with Ant & AMdy, one of which I guess marked your card... so blame them for sending you chasing wild geese (beginning to get the hint yet you defector - you can go get stuffed but make my apologies to Sue )

[clive f]

OI! you implying I`ve put on weight?

I`m still smoking you know

[spend]

I bet you were just hoping he'd get his bin bag & wig out if he spent long enough in the car park, you randy old sheep worrier

been dreaming of christening the AM bonnet with Voluptia have you then?

[spend]

Quinny said:

spend said:

I bet you were just hoping he'd get his bin bag & wig out if he spent long enough in the car park, you randy old sheep worrier

been dreaming of christening the AM bonnet with Voluptia have you then?

Good god no..... It's only aluminum you know

Cliffs an absolute genie at fking with aluminium you know

[V8Bart]

Just done stelvio pass along with another 2500 miles, got alot of good audio for an act Y piece and cherrybomb with full decat.
plenty loud and lots of burble and the odd flame. will be a week before I can post though.

[Pupp]

spend said:

I'm not convinced that's totally right Cliff. There are quite a few Nascar collectors where they merge 4 into a big st off pipe and then step it down after a decent run of the thick bit. I'll agree it doesn't look right but they must do it for pure performance (flow) reasons in Nascar?

Effectively, the engine sees the large volume as if 'atmosphere' and the header length will be some harmonic of 30ish inches from bore centre to pipe end (into quasi-atmosphere). The square cut ends of the headers in the collector promote standing waves that, with the right header length (around that magic 30ish inches that all engines seem to like) can be tuned to improve scavenging/filling of the chamber. Starts getting really tricky when separators are introduced between the header terminations etc. Have lost loads of HP playing with bike systems, rarely gained much but did manage to move it around

The interesting trick you dont see so much with car systems that's very common (especially with Yank systems) on bikes, is a ramped, flat-topped 'step' on the floor of the exhaust port/header union (often formed in the billet flanges that bolt to the heads and accept spring-fit pipework). Idea seems to be to trigger reflections/pulses right outside the port, or possibly increase gas speed through ssome sort of venturi effect (usually right in front and on the inside of a tight bend in the pipe)

[jackg]

OK thanks for your input.

I'm going to go with ACT Y piece and decatted manifold plus their induction system. I'm also going to get some Nitron Shocks.

Anything else I may need?