Member Profile - Ferret

[THE SpecB]

Well Alexi ? No comment ?

[alexeiwoody]

Well Alexi ? No comment ?

Hey, sorry mate - are you asking about XForce? I honestly don't know? You could measure it

Don't think it would make a big difference either way, as long as the y pipe is nicer flowing/larger than stock, because stock y pipe is terrible.

[ferret89]

Very interesting thanks Alexei.

So what is your opinion on running a 3" DP and Mid to a 2.5" Y to the small inlet STI quads (1.75" I think) on a car doing under 200atw?

Hey Daniel, it's quite a common setup, for whatever reason the Sti quads are a popular choice, and it's worked quite well for most people

If the car is tuned accordingly by a careful tuner, there wouldn't be any problems. Overall maybe you're not optimising the 5kw you might get with bigger mufflers, but I'd say the noise isn't worth 5kw.

Once you go to a bigger turbo and/or E85 - you'd want to open up some more flow, but on stock or even vf52 on 98, should be adequate. We're lucky to have dual exhaust on the lib (we don't have to run a giant cannon muff)

Cheers Alexei, thanks for all your help.

I know I probably seem to be overthinking a simple exhaust a bit but it's just how I work I like getting as much feedback and advice as I can

I've booked it in to have this fitted, I'm confident it will benefit overall flow and not increase noise/drone too much. Not expecting much of a power hike, maybe only a few kw but some extra torque down low and mid range is always welcome

[Shaheenis]

So your going to accept the blunt edge transition? You realise it will be a ~12.7mm step down - imagine the disruption to airflow. I spoke with Chris from Best Mufflers about this a year or so back and he agreed with me and recommended against it.

Either way I will be interested to see how you get on. There is some good information in one of my old threads from a tonne of forum members 'Weak Links in Gen4 Exhaust' which may be of use.

THE SpecB I am convinced you are NewbieGT. Call it a conspiracy .

[THE SpecB]

So your going to accept the blunt edge transition? You realise it will be a ~12.7mm step down - imagine the disruption to airflow. I spoke with Chris from Best Mufflers about this a year or so back and he agreed with me and recommended against it.

Either way I will be interested to see how you get on. There is some good information in one of my old threads from a tonne of forum members 'Weak Links in Gen4 Exhaust' which may be of use.

THE SpecB I am convinced you are NewbieGT. Call it a conspiracy .

Tim I suggest you keep your opinions to yourself. Don't assume or speculate. I am not another forum member so stop stating I am.

[Shaheenis]

It is the first time I have mentioned it so you may also have me confused with someone else . No offence intended just an observation.

[ferret89]

So your going to accept the blunt edge transition? You realise it will be a ~12.7mm step down - imagine the disruption to airflow. I spoke with Chris from Best Mufflers about this a year or so back and he agreed with me and recommended against it.

Either way I will be interested to see how you get on. There is some good information in one of my old threads from a tonne of forum members 'Weak Links in Gen4 Exhaust' which may be of use.

THE SpecB I am convinced you are NewbieGT. Call it a conspiracy .

I haven't heard back from Trevor yet but it's not booked in till end of next week so there's no hurry.

I'm confident that the transition from free flowing Y-pipe to restricting STI quads won't be too much of a big deal. Worst case I won't gain any benefits other than noise and best case is that I will see small gains in performance and sound. Ideally for power I'd be swapping the mufflers for better ones but I'm going to see how it sounds and goes after this before I think about that.

[Shaheenis]

Did you manage to get just the centre and Y pipe? If you get a chance, take some verniers and measure the ID on the Y-pipe - inside the pipe, not the flange. I have an idea .

[Brunsy3.0]

Hey Budd just had a read through your thread. Some bad luck with the paint hopefully ended up with results you were happy with. Sounds like you think things through mate, some good stuff and a good read

[ferret89]

Did you manage to get just the centre and Y pipe? If you get a chance, take some verniers and measure the ID on the Y-pipe - inside the pipe, not the flange. I have an idea .

Negative, Trevor ordered the cat-back for me for the same price that Best mufflers could do it for minus the postage costs though so I took that.

I'll measure the ID when I get the chance and let you know. I would assume that the Y-pipe wouldn't be 3" all the way though..

Thanks Daniel I've definitely had a few dramas with it but it's going great now

[Brunsy3.0]

Thanks Daniel I've definitely had a few dramas with it but it's going great now

I dont think itd be as well deserved if we didnt have set backs along the way. Im finding it more of a rarity to have smooth sailing in the modification game

[ferret89]

XForce Cat-back installed today to my STI quads. Sounds nice and deep, volume increased for sure but I didn't find it too loud or intrusive on the drive home. Trevor welded on new flanges to the Y-pipe that reduced ID smoothly to the quad muffler flanges, he thought that was the best solution rather than to cut up the mufflers. I didn't measure the pipes but it looked like it was 3" all the way to the Y and then decreased to at least 2.5" possibly even 2.25" so should definitely flow a fair bit better through there. Not too impressed by the weld quality on the XForce pipes though, I suppose the old saying you get what you pay for holds true here...

Warning: A lot of photos

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Stock cat-back section: Looking a bit thin and rusty, notice the crushed area near the Y

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XForce cat-back: Aluminised mild steel or some kind of coating? Check those welds though

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Shot from the rear of the Stock vs XForce Y-pipe

[ferret89]

Also took a few quick shots of the CES dump and cat while the car was on the hoist

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[Shaheenis]

Dan, stock Y-pipes are 1.5". It is good to see you made some effort to tapper the connection as it will help but based on the pictures of the transition there would still be a decent step down. Looking at your photos (thanks for posting all of these) it doesn't look like there would be any easy way of improving it with stock mufflers.

How different is the sound? Is it what you were hoping for?

[ferret89]

Dan, stock Y-pipes are 1.5". It is good to see you made some effort to tapper the connection as it will help but based on the pictures of the transition there would still be a decent step down. Looking at your photos (thanks for posting all of these) it doesn't look like there would be any easy way of improving it with stock mufflers.

How different is the sound? Is it what you were hoping for?

Unless you were to replace the whole inlet pipe + flange on both mufflers and taper it from say 1.75" to 2.25" by the time it connects to the Y pipe or something?

It sounds great, much more noticeable boxer rumble and much deeper. I'll post up a video tomorrow or on Sunday the same way I did the other video to directly compare. The journey home is about 20km on the highway and I didn't notice any annoying drone or anything and it should only quieten down from here once it carbons up.