Exhaust options

[Diablos-666]

I'm considering changing the std exhaust on my t350c, but have a few queries...

1) - I want something that will give additional power gains (have any been proved to do this?)

2) - Will a de-cat system reduce under bonnet temps?

3) - Louder pops & bangs as well as flames on the over-run would be nice

4) - I often drive with the window open so dont want something TOO loud.

What, if any, exhaust is the best option for the above - The list is in order of priority.

Regards,

D

[Zippee]

My responses in bold;

Diablos-666 said:

I'm considering changing the std exhaust on my t350c, but have a few queries...

1) - I want something that will give additional power gains (have any been proved to do this?)
As far as I'm aware - no

2) - Will a de-cat system reduce under bonnet temps?
It'll certainly help reduce the in cabin/trans tunnel temps. De-cats on their own IMHO sound a little raspy. Mated with a sports backbox they can be incredibly loud

3) - Louder pops & bangs as well as flames on the over-run would be nice
I have a JP box on the back of mine and the over-run is awesome. Only way you'll get flames is to combine it with a de-cat and map for a bit of over fuelling

4) - I often drive with the window open so dont want something TOO loud.
Don't get a de-cat and sports box in that case! Try and get to listen to the various options first - many of these are on youtube but it's hard to guauge real life sound from there. Blueflame is the quietist of the aftermarket pipes, followed by JP and then Powers. My JP is loud from the rear but actually less droney in the cabin.

What, if any, exhaust is the best option for the above - The list is in order of priority.

Regards,

D

[Diablos-666]

Thanks Zippy - Quiet surprised about the lack of power gain really? I suppose a sports exhaust will be lighter than the std one so at least that is something I suppose.

The reduced temps will be good, even in the transaxle as the gear knob can get quiet hot.

If there are no power gains then i'm thinking maybe just get the std exhaust de-catted? This would reduce weight, reduce temps, make it a bit louder and may get flames on the over-run. The only downside is putting the cat back on come MOT time and then taking it off again.

Is the noise just too much de-catted though?

[Zippee]

Just a de-cat with standard pipes is pretty much the same noise level as my JP. However, as I stated I personally don't like the raspy sound off it, they don't mate very well with the OEM box IMHO.
I think before you start spending money you really need to find examples and listen to the different options in the flesh. NTELS decats are around £240 plus fitting, a JP box is £395 plus fitting so either way it's a lot of money to spend if you've not heard the results. Also remember if you de-cat it would also be a good idea to go for Powers de-cat chip and that will also need to be factored into the price.

[fredd1e]

My T350 is decatted with a stock back box, and I dont think its loud, however I am comparing it with when I got it with sports exhaust and decats which was incredibly loud.
No idea on the make of the sports exhaust but it was a small can each side at the rear with chrome/polished ends connected to the separate exhaust pipes so no join between each bank of 3 cylinders

[Diablos-666]

As for the chip i had read that the management on a speed six is a live mapping "closed loop," system so it is always adjusting and correcting the fuelling.
The pops and bangs is unburnt fuel simply igniting in the decats which the cats themselves would have otherwise absorbed.

So there would be no need for a chip?

[Zippee]

fredd1e said:

No idea on the make of the sports exhaust but it was a small can each side at the rear with chrome/polished ends connected to the separate exhaust pipes so no join between each bank of 3 cylinders

Powers box is like that - 2 separate pieces.

[Bolt666]

Me recently at SELOC games

http://www.youtube.com/watch?v=qyiscJof6W4&fea...


TVR power exhaust, sounds awesome. It is loud and I do have my windows open alot and after a drive my ears to ring, but its worth it!

Note the chap recording who posted it made the comment 'this was the best bit of the day' so I think the exhaust does a great job!

[darkmark07]

Diablos-666 said:

As for the chip i had read that the management on a speed six is a live mapping "closed loop," system so it is always adjusting and correcting the fuelling.
The pops and bangs is unburnt fuel simply igniting in the decats which the cats themselves would have otherwise absorbed.

So there would be no need for a chip?

Hmmm, be careful - the chip works out the fueling based on certain parameters - throttle position, air temp etc. etc. but bases this on a 'lookup table' for want of a better description. In many instances, these tables were not fully populated at the factory and they evolved over the life of the S6 engine.

As someone who had the car decatted (thanks to NTEL) and had the updated engine maps (thanks to TVR Power), I can genuinely recommend both. Not in terms of any real performance gains (although pops and bangs are nice) but in real drivability and cold running.

I can understand Zippee's comments about it being raspier, it is. I would take issue about it being 'as loud' at the JP exhaust on a standard setup - Zippee's measured c. 105db @ 4,000rpm - mine is c. 99db.

Tony (Zippee) and I were going to spend some time swapping components between cars and see if there were any performance gains on a rolling road (and to check the sound levels) but haven't found the time so far.

My standard back box has a loose baffle so will need replacing - I'm tempted to go for a JP exhaust but I suspect the neighbours (and the missus) will object somewhat!

[LeeT350c]

I have a video of mine on the rollers totally standard here along with the graphs.

http://www.youtube.com/watch?v=J-T1i4GGS7I

Once de-catted and mapped I might run it again to see if there is any difference.

Cheers. Lee.

[TVR Andy]

I have a 350t with the JP exhaust & Oxford is not far from you if youwant to listen to mine sometime?

[Targarama]

darkmark07 said:

Hmmm, be careful - the chip works out the fueling based on certain parameters - throttle position, air temp etc. etc. but bases this on a 'lookup table' for want of a better description. In many instances, these tables were not fully populated at the factory and they evolved over the life of the S6 engine.

Agreed. My T350 was re-chipped (EPROM in ECU) by Mark Adams back in 2005. He found a lot of the fields in the factory PROM in my car were empty and had to populate them manually, took a bit longer.

There is one exhaust sold by ACT (I forget the manufacturer), which may increase power with a rechip/rolling road session. Take a look at STUB101's recent thread on the system (his car was used as the template for this system).

Edited by Targarama on Friday 23 July 20:48

[Zippee]

darkmark07 said:

I can understand Zippee's comments about it being raspier, it is. I would take issue about it being 'as loud' at the JP exhaust on a standard setup - Zippee's measured c. 105db @ 4,000rpm - mine is c. 99db.

Tony (Zippee) and I were going to spend some time swapping components between cars and see if there were any performance gains on a rolling road (and to check the sound levels) but haven't found the time so far.

My standard back box has a loose baffle so will need replacing - I'm tempted to go for a JP exhaust but I suspect the neighbours (and the missus) will object somewhat!

Hi Mark

We must get round to sorting that out. One of my cats is starting to break up a little so I may well be heading the really noisy route towards the end of the year anyway. Didn't mean any offence with your car BTW - just prefer the sound of the JP if I had to select only 1 option. I'd certainly echo your comments on the de-cat chip as well, something my car actually has already - found an invoice for it amongst the previous owners history.

[clive f]

I was chatting to Joolz last weekend who said they had a speed 6 car on the dyno, and did back to back power runs with cats and decats, interestly enough, the decats gave a very small marginal increase in bhp right at the top end, but lost power in the mid range compared to the cats.

I have decats and a standard silencer, I quite like the noise, ideal for cruising ect and raspy when the pedal goes down, comfortable in the car, still able to talk to the passenger without shouting, I do also have the sports tail pipes to go on, which I will try out for a couple of weeks to see if I can live with it, if not I`ll put it back to its present set up.

[shep1001]

Zippee said:

fredd1e said:

No idea on the make of the sports exhaust but it was a small can each side at the rear with chrome/polished ends connected to the separate exhaust pipes so no join between each bank of 3 cylinders

Powers box is like that - 2 separate pieces.

They would be TVR Power or Racing Green 'Super sport' cans got a pair for my Tam. They are awsome. Bang & pop like an AK-47 on the over run and the 'war cry' when you are gunning it (6k+ revs) is something else.

Shep

[Diablos-666]

Can you only get flames by a de-catted exhaust, or you achieve this with one of the many sports exhaust you guys have been mentioning?

Flames would be nice but would imagine it would be a pita come MOT time when you need to put them back in.

[thainy77]

You need it de-catted for flames.

Putting the cats in should only take about 30 minutes if you have good access to them. Some people do manage to pass their MOT with de-cats.

[Targarama]

Diablos-666 said:

Can you only get flames by a de-catted exhaust, or you achieve this with one of the many sports exhaust you guys have been mentioning?

Flames would be nice but would imagine it would be a pita come MOT time when you need to put them back in.

Best thing would be to have a service and MOT scheduled together and have Jason's team do what is needed to get the car through the MOT, and then revert back before handing you the car. Might be simpler than you think.

[Lensey]

Mine is decatted and when I had the first mot done I got them to put the catts back in test it then take them back out again, when I took it for the second mot they couldn't be bothered to do it all again so they "sorted" it and have done that ever since, next mot is due next week and they are doing the same thing, I suggest you get a sympathetic garage as they can get it through the mot without the catts if they want to I do find it funny that they insist I put the legal number plates on the car though!

[darkmark07]

Targarama said:

Best thing would be to have a service and MOT scheduled together

^

And Zippee - no offense taken at all