Stis

Active Member
Jan 13, 2011
292
0
Derby
Right, my friends bought a leon FR, the 2.0ltr 170ps - he's gone to get it remapped to a stage 1, and they've told him he'll see added benefit from a blow off / recirc valve.

he's asked me, and i don't know, so i said i'd ask SCN :)

so, i understand that he'd probably get better throttle response, maybe less drop between gear changes, but is it really needed? and would it make the little "tsss" blow off when he changed gears etc? i mean, is that really a good noise coming from a diesel? and won't it be ridiculously loud since the pressure is higher?

any help would be greatly appreciated - thanks SCN
 
Can't say I've seen that mentioned for a TDI. Stage 1 Remap only first of all, then if you want more grunt DPF delete and/or new exhaust along with a Stage 2 Remap.
 
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Remp company are making a mistake, they are mixing up the 2.0 Turbo Diesel FR with the 2.0 Turbo petrol FR.

Dump valves don't work on diesels well you can spend about £300 on a special electronic one that does but it sounds poop.
 
My brother gets that kind of noise on his 1.9TDi MK5 Golf and all he did was have the back box cut off and a straight through exhaust from Powerflow fitted. Sounds kinda cool when he changes in the first 3 gears but after a bit just gets annoying.

Just my little bit of input on how easy it is to achieve that noise if you wanted to do it lol
 
My brother gets that kind of noise on his 1.9TDi MK5 Golf and all he did was have the back box cut off and a straight through exhaust from Powerflow fitted. Sounds kinda cool when he changes in the first 3 gears but after a bit just gets annoying.

Just my little bit of input on how easy it is to achieve that noise if you wanted to do it lol

you can't get that on the 170 can't remember why, Andrew told me once. It coo's I think
 
That's your turbo coming to an abrupt stop due to pressure trying to equalise on either side of the turbo impeller or something.

As for blow offs, that's only possible with a waste gate type turbo which is why you can't have it on the tdi.
 
the pd140 has a waste gate turbo but the 170 doesnt from what i can remember
 
I think it was just the older tdi's that had a waste gate like the 1Z AHU and the AGR, also I don't think the waste gated tdi produces enough waste gas to operate a blow off valve.
 
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remap company are talking utter crap and if they are indeed quoting this work for your mates FR TDI i would tell him to go elsewhere as thier work cant be very professional if they are giving advice like that
 
Can't say I've seen that mentioned for a TDI. Stage 1 Remap only first of all, then if you want more grunt DPF delete and/or new exhaust along with a Stage 2 Remap.

So no changes whatsoever to the induction are needed, even at a stage 2?


So the real question is do you trust the remap company, if their talking fubar? who was it?

I’m not sure mate, I never asked him. I will drop him a text today though and get back to you mate


Remp company are making a mistake, they are mixing up the 2.0 Turbo Diesel FR with the 2.0 Turbo petrol FR.

Dump valves don't work on diesels well you can spend about £300 on a special electronic one that does but it sounds poop.

So it is possible? I’ve heard a diesel go past me before, it was a seat Ibiza cupra, the 160ps model. The guy was a bit of a bellbin and he was ragging his car up and down the car park, each time he let off there was a stupidly loud “tssss” noise coming from his engine – needless to say, his car was pretty slow


Lets hope they don't get them mixed when they put the map on lol

Haha, I was just thinking this when it was said above


That's your turbo coming to an abrupt stop due to pressure trying to equalise on either side of the turbo impeller or something.

As for blow offs, that's only possible with a waste gate type turbo which is why you can't have it on the tdi.

Its not coming to an abrupt stop, when you let off the accelerator you’re closing the throttle body and reducing the air flow massive amounts. The blow off then opens and is dropping back pressure to stop the air forcing itself back out past the turbo in the opposite direction.

With the turbo being an impeller that will cause the turbo to slow down rapidly, and if there is enough pressure it’ll cause the turbo to stop and spin the other way. So you drop the back pressure straight away, allowing the turbo to freely spool, then when you’re back on the power the turbo can jump back into action and continue to draw air in – so with a performance blow off, you drop pressure quicker and more efficiently, meaning your throttle response improves since you’re turbo is more active, and you probably get a slight acceleration increase since you’re not having to waste time spooling the turbo back up, reducing the ol’ turbo lag

That’s the way I understand it anyway.


Ahh and doesn't work on the FR's because its a different turbo

Whats different about it?


the pd140 has a waste gate turbo but the 170 doesnt from what i can remember

What does this mean? haha


remap company are talking utter crap and if they are indeed quoting this work for your mates FR TDI i would tell him to go elsewhere as thier work cant be very professional if they are giving advice like that

Derbyforget where are you from mate?
And I think you’re right in saying he’s probably better going elsewhere
 
Lol nice multiple quote reply. Can't remember differences in turbo think its on Wikipedia lol but there is no need to change the air induction on a tdi as it has too much air intake already with the standard box