Viewing: Too small exhaust for tuning

**deedee** · 27-04-2009, 10:37 PM

The little might seem a bit strange but im getting my car remapped and was speaking to a mate who says get it mapped and an exhaust cause if they know its got a bigger exhaust they can up the boost as it will get out quicker? is this true? do you have to upgrade your exhaust system first or you can do some mods then your exhaust?

***HDi fun*** · 27-04-2009, 11:20 PM

Quote:

Originally Posted by deedee

The little might seem a bit strange but im getting my car remapped and was speaking to a mate who says get it mapped and an exhaust cause if they know its got a bigger exhaust they can up the boost as it will get out quicker? is this true? do you have to upgrade your exhaust system first or you can do some mods then your exhaust?

Diesels, generally, are pretty free flowing anyway. They're made this way because the engines have no throttle as such.

If your car can be remapped via the OBD2 port (which a PD130 can be so) then do that first and then decide afterwards if you really need any more mods!

Manufacturers even now undertune some of their diesel models from the factory simply to leave a space in the market for their petrol powered equivalents.

Remapped diesel cars can be a bit brutal to drive in the lower gears (and this doesn't help to sell new cars in general) with their tyre squealing 3rd gear acceleration. It can alienate the customer who's after a diesel for economy, perhaps.

**deedee** · 27-04-2009, 11:23 PM

so just cause it will have a standard exhaust it can still get mapped to its full boost it doesnt matter if they can force more air out it or not? I just don't want to get it done then someone to be like if you got the exhaust done you can get more power as the air is getting out quicker? So more fuel/air can be shoved in.

Whats the next step after a map for performace mods?

***HDi fun*** · 27-04-2009, 11:29 PM

Quote:

Originally Posted by deedee

so just cause it will have a standard exhaust it can still get mapped to its full boost it doesnt matter if they can force more air out it or not? I just don't want to get it done then someone to be like if you got the exhaust done you can get more power as the air is getting out quicker? So more fuel/air can be shoved in.

Whats the next step after a map for performace mods?

"I just don't want to get it done then someone to be like if you got the exhaust done you can get more power as the air is getting out quicker?"

What do you mean when you say 'to be like'?

**deedee** · 27-04-2009, 11:33 PM

just i don't want to get it mapped but no exhaust then someone to say you could have gotten more boost or more air:fuel in as it wil leave quicker due to a bigger exhaust.

A car with remap
A car with exhaust then remap

Which will give more power from the REMAP? or will it be the same? just one will have more due to the exhaust

***HDi fun*** · 27-04-2009, 11:43 PM

The PD130 engine is more than capable of breathing freely as it is in the Golf you have.

A remap will give you over 170bhp with no other changes. What you'll really notice is the massive midrange torque that will be realised.

VW diesels have pretty free flowing exhausts anyway. THey have to - diesel engines HAVE NO THROTTLE - they run on excess air. That's how they achieve their easy gait at low/mid revs.

If you really want to make a lot of noise then splash five hundred quid on a full exhaust first. It'll probably score you 2bhp at best.

Even if you fit the exhaust after the map the ECU will still take account of the very minimal extra gas flow and give you that 2bhp.

Bear in mind this - the biggest problem with any car that's turbocharged is that the turbo(s) restrict the gas flow far more than any standard exhaust. So, would you be willing to remove the turbocharger(s) to fix this??

I doubt it.

**deedee** · 27-04-2009, 11:46 PM

so your saying i could do a far few mods and not need to change the exhaust to let all the air come out thats been sucked in?

So whats the next mod afetr a remap then?

***HDi fun*** · 27-04-2009, 11:58 PM

Diesel engines have no throttle. They breathe freely. If I were you I'd get the car remapped fisrtly and then decide whether you need any more mods.

Don't piss about with intake kits - they're worth little at all in this situation. Exhausts - and I repeat - diesel engines are free flowing anyway. The biggest encumbment will be the turbo(s)

A decent remap will give you more shove than you ever imagined was possible for the 200-300 quid it'll cost to have done. The only pre-requisite is that your car is properly serviced and running correctly before you get it done.

If you really want to get involved then buy up half a dozen standard air filter elements and keep them on standby.

And maybe a job lot of Millers Diesel Sport 4 additive - it's good stuff - ramps up the cetane of the fuel you fill the tank with.

**pgarner** · 28-04-2009, 12:41 PM

Quote:

Originally Posted by deedee

so your saying i could do a far few mods and not need to change the exhaust to let all the air come out thats been sucked in?

So whats the next mod afetr a remap then?

hybrid turbo, then exhaust as you will be running more boost.
there is NO point, as you have been told, in changing the exhaust before a hybrid turbo is fitted as the turbo can only run so much boost before blowing itself up. the only real ristriction in the exhaust itself is the cat, but even changing this your possible only looking around 5 bhp.
as i said in your welcome you can go for CAI if you want for a few more bhp but nothing youd really notic, other than the noise. you be cheaper to remove your airbox and smooth out the airbox then refit

**MasterAuron** · 28-04-2009, 05:34 PM

It's not about running more boost. If (and I say IF) you get a less restrictive exhaust you will make more power at the same boost and get less lag. But if these boys say the exhaust is fine as it is, then it's fine as it is. They know their VAG engines.

***HDi fun*** · 28-04-2009, 07:08 PM

Celtic offers 180bhp and an whopping 310lbft of torque for your PD130.

You WILL NOTICE THAT TORQUE. BIG TIME!!!

Turn the EDL off and you'll send it up the road, tyres squealing, in third gear.

My advice - GO FOR IT!!!!

**pgarner** · 29-04-2009, 10:05 AM

ESP in the golf

***HDi fun*** · 29-04-2009, 10:54 AM

Trust me, you'll be blown away by the midrange acceleration.

**sr performance** · 01-05-2009, 12:32 AM

Hi, max you will get out of the 130 tdi is 175bhp and that is everything maxed out on the limit, fact..
we had one on rollers which belonged to lad that was mapping it, and there was no way a customers car would be mapped to push out more than 170 as there was no room for safety margin..
maxed out it outdragged a ferarri 360 3rd gear rolling test up to 120mph, torque beats a car that needs to rev..

steve