To de-cat or not to de-cat? That is the question...

[flagpole]

Been umm-ing and err-ing for a few weeks on this now... Got a JP sports exhaust on my Tam and don't get me wrong it sounds great. However, have heard some other TVRs that have been de-catted and they do sound awesome. The extra power doesn't bother me (although can never have too many horses under the bonnet!), just not sure if I should go for it?

What do people generally think about de-catting? Also what sort of figure are we looking at cash wise?

Looking forward to hearing people's advice and thoughts on this...

Cheers,

Flagpole.

[zooooom]

Well there are a couple of down sides to de-catting.

1.You will have to refit them before every MOT otherwise its will fail on the emissions part of the test.

2. I think you have to change or remap the ECU , so dont no what happens when you refit the cats for MOT.

[T5SOR]

De-Cat Saggy sounds good

[the pits]

Did you have to re-map the ecu?

[DJC]

You dont need to touch the ECU.

[Mr Freefall]

DJC said:

You dont need to touch the ECU.

That depends who you talk to!

The speed 6 uses the back pressure to help shut the valves, so if you take away the back pressure, you have to replace or alter other things to compensate. Dom does a de-catt chip for the Speed 6, which changes the ignition slightly across the rev range and the fueling in the lower rev's to help compensate for the loss of back pressure.

As I recall, £250+ VAT for the decatts and the chip. The de-catts pipes are actually the catts with the insides removed.

Ask Dom at Power see what he has to say.

Oh, decatt and JP if flipping loud, I did this on my T350.

Mr F

[zooooom]

DJC said:

You dont need to touch the ECU.

S**T that not what my dealer told me when I asked about decatting my car!
Guess I will retract No 2

[T5SOR]

the pits said:

Did you have to re-map the ecu?

Well it's my dads (L1OFF) not mine but he sais there is no loss of power, unlike the Tuscan!



Mike

[funky]

Does anyone know of any video samples of a saggy with de-catted? Just to hear the difference

[flagpole]

funky said:

Does anyone know of any video samples of a saggy with de-catted? Just to hear the difference

Now that's a great idea! Or even any of the Tam de-catted? !!

[T5SOR]

No vid im afraid. sounds alot better. Abit louder on start up, much more backfire and a pop on gearchange


Mike

[flagpole]

So Mike, in your opinion, should I go for this? I am beginning to think 'yes' but would it make that much difference to the sound?

Thanks,

Flagpole.

Edited by flagpole on Monday 28th August 20:51

[T5SOR]

Well from my limited experience i would. Had a de-catted Cerb, Tuscan and Saggy and they all sound alot better for it! Cerb sounded like a machine gun, Tuscan like a bomb and the Saggy like cannon fire

[flagpole]

And I will let you know how the Tamora sounds! Thanks Mike

[DJC]

Mr Freefall said:

DJC said:

You dont need to touch the ECU.

That depends who you talk to!

The speed 6 uses the back pressure to help shut the valves, so if you take away the back pressure, you have to replace or alter other things to compensate. Dom does a de-catt chip for the Speed 6, which changes the ignition slightly across the rev range and the fueling in the lower rev's to help compensate for the loss of back pressure.

As I recall, £250+ VAT for the decatts and the chip. The de-catts pipes are actually the catts with the insides removed.

Ask Dom at Power see what he has to say.

Oh, decatt and JP if flipping loud, I did this on my T350.

Mr F

It does indeed depend on who you talk to. You still dont need to touch the ECU though.

[nubbin]

Just had the Tamora decatted - and TVR Power chip - it is necessary to change the mapping slightly. The main thing is that the noise is louder, and the exhaust crackles, pops, bangs and then goes BANG! with flames out of the exhaust!

However, what is much more apparent is that it revs even more easily - the engine responsiveness is quicker, smoother and it flies through the rev range - may be the chip has a better fuel map, or the reduced back pressure has other benefits - I don't know, but it is more driveable. Definitely worth it, as long as you have a friendly TVR outlet for the MOT!

[whitey]

have you seen the flames? Mine is certainly very loud but not had a chance to find out if it's actually flaming or not!

[nubbin]

whitey said:

have you seen the flames? Mine is certainly very loud but not had a chance to find out if it's actually flaming or not!

No, but the guy who did the decat has seen them at night in his workshop. I'm waiting for the chance to get out at night and check the results!

[kiefh]

i have had my tam decatted and i had to have a chip put in by power that levels out the fuel well sumthing like that anyway.when it gets revved its a sonic boom and best of all it flames defo a must and you dont have to put the cats back on if you know the right people

[tail slide]

kiefh said:

i have had my tam decatted and i had to have a chip put in by power that levels out the fuel well sumthing like that anyway.when it gets revved its a sonic boom and best of all it flames defo a must and you dont have to put the cats back on if you know the right people

Just getting mine done, trying no chip first, & hope to avoid annual replacement. As MoT's are now computer-linked to the testing gubbins, assume you mean that if the engine's hot enough it should run cleanly enough to pass? A friend runs the local garage - he'll help but won't totally cheat!