Some questions ive all wondered the answer too

[deedee]

As im not the most knowledgable person about cars, tuning etc ive always wondered the answer to some of these questions and hopeing they can get answered here, some of them relate to both petrol and diesel but as ive got a diesel thought id post in here.

1. Can i get my red line extended, eg from 4500 rpm to 5000 rpm ? just to allow the engine to rev that bit harded.

2. Whats the diffrence between a custom and generic remap?

3. How safe it nitrous? ive heard now adays nitrous kits are very safe and only blow your car if you use it when your not supposed to. Also how much can you use on a 4 cylinder diesel engine?

4. Do performance exhuast or bigger exhausts, eg going from 2 inch to 2.5 make a big diffrence in power ? what about de cat pipes?

5. When driving my car 99 % of the time my engine temp gauge is at the lwoest point like its not working. It does it when driven normal and hard. It will sometimes go up o 90 degree ( half way ) or sometimes just below. The car still runs the same and no warning lights. Ive heard this is something to do witht the radiator ?

6. I was looking at putting a boost controller in my car. does this control how much boost you put through, eg set it to 100 bhp or then crank it up too 180 ?

7. Is there anyways to stop a diesel from sounding like that diesel sound. I mean i dont want it too sound like a petrol just not like walking through a fairground.

8. Whats the best type of air intake ? induction kits or panel filters ? I know induction kits cost more and sound terrible but is there a diffrence in bhp gain?

9. When would you put silicone hoses in your car, you know thoses big coloured hoses, i think they look cool but there must be a real reason ?

10. Is there anyway to get rid of rust once its through, or if its starting to buble through the paint ?

 

[HDi fun]

As im not the most knowledgable person about cars, tuning etc ive always wondered the answer to some of these questions and hopeing they can get answered here, some of them relate to both petrol and diesel but as ive got a diesel thought id post in here.

1. Can i get my red line extended, eg from 4500 rpm to 5000 rpm ? just to allow the engine to rev that bit harded.

No point - diesel engines don't give much benefit over 4000rpmany

2. Whats the diffrence between a custom and generic remap?

A generic is based upon another identical car. A custom is based upon your own car, it's diag data and your specific requirements

3. How safe it nitrous? ive heard now adays nitrous kits are very safe and only blow your car if you use it when your not supposed to. Also how much can you use on a 4 cylinder diesel engine?

Nitrous is very expensive way to gain power for a very very short time. 10-15 seconds at a cost of about £1 per second before installing the kit. It's also illegal to use on UK roads

4. Do performance exhuast or bigger exhausts, eg going from 2 inch to 2.5 make a big diffrence in power ? what about de cat pipes?

De cat will help, although you might struggle with MoT emissions tests.

5. When driving my car 99 % of the time my engine temp gauge is at the lwoest point like its not working. It does it when driven normal and hard. It will sometimes go up o 90 degree ( half way ) or sometimes just below. The car still runs the same and no warning lights. Ive heard this is something to do witht the radiator ?

Temperature sensor faulty perhaps - get the car on a diagnostic rig

6. I was looking at putting a boost controller in my car. does this control how much boost you put through, eg set it to 100 bhp or then crank it up too 180 ?

This would be done in software with your car.

7. Is there anyways to stop a diesel from sounding like that diesel sound. I mean i dont want it too sound like a petrol just not like walking through a fairground.

Don't buy a 4 cylinder VW diesel

8. Whats the best type of air intake ? induction kits or panel filters ? I know induction kits cost more and sound terrible but is there a diffrence in bhp gain?

A clean drop in filter is pretty good anyway.

9. When would you put silicone hoses in your car, you know thoses big coloured hoses, i think they look cool but there must be a real reason ?

No really, but they look nice

10. Is there anyway to get rid of rust once its through, or if its starting to buble through the paint ?

Can't help with that one.

 

[deedee]

so about question 1. i read in another post HDI, your red line on your 406 went to around 5-5400 rpm was it not? and you had it mapped? so would ou not get power to the red line anyways.

3. didnt know it was illegal. One of my mates has a 75 hp shot in his motor. Hardly ever turns it on at the bottol though.

6. how exactly does the boost controller work ? can you end up over boosting the car and blowing the turbo?

 

[HDi fun]

so about question 1. i read in another post HDI, your red line on your 406 went to around 5-5400 rpm was it not? and you had it mapped? so would ou not get power to the red line anyways.

3. didnt know it was illegal. One of my mates has a 75 hp shot in his motor. Hardly ever turns it on at the bottol though.

6. how exactly does the boost controller work ? can you end up over boosting the car and blowing the turbo?

Yes, the red line was at over 5000rpm but the HDi 2.2 I had was a twin-cam 16 valve engine which possibly allowed it to breathe a little more freely. The PD150s are eight valve units (quite enough anyway, in my opinion) Even so, there was never any need to go beyond 4000 as the torque curve still dropped off quite steeply beyond that point.

The remap did give more torque across the whole rev range but by their nature, diesel engines don't really give their best at high revs. What the (custom) map did do was smooth out the torque delivery across the whole range and give a substantial increase in acceleration in all gears. 30-60 in third was under 5 seconds, for example!!!

Peak power was RR'd at about 192bhp, torque around 330lbft, which is well worth having.

NITROUS. OK, It's not illegal to install it on a road car. However, if you are driving it on the road then one part of the system must be removed (a fuse, perhaps) so that it cannot be operated on the road. If the system is fully functional and available for use on the road then the use of the car on the road would be considered to be unlawful. It's generally reserved for drag strip racing where every 1/10 second counts.

Boost pressure, turbo vane angle etc. is now under ECU control so you can't just fit a twisty knob to the dash any more. There are some remapping methods which allow you to alter the car's performance profile at your own discretion. Bluefin is one such device. Celtic tuning now have something similar. In both cases, as far as I'm aware, you cannot 'swap' maps whilst the car is in motion as the change itself requires a full download of engine control parameters to the ECU.

My opinion of having multiple maps for road use is simply this:-

get a custom remap that suits you, your car and your driving for most of the time. They can alter throttle pedal response rates etc. to give the car a feel that suits you best. Some like a very sudden response, other drivers prefer to dig deeper with the pedal to get a result. Either way, you can control the power delivery with your right foot. So, if you need less torque and power, then lift off the right foot a little.

Overboosting can wreck turbochargers - it can also lead to fuel starvation and reduce performance significantly. All good tuning companies will work within the safe parameters for your car.

A well mapped Golf PD150 is a very very lively drive indeed. You will like it, trust me.

If you do choose to remap your car (and why not - there's nothing to lose) then do keep up your servicing schedule.

As with any turbocharged car, let it idle for a minute of two before pulling the key. Similarly, don't use full power until the engine is properly warmed up. (Get that temp gauge looked at as well - if the ECU is using the same false information then you could well struggle with emissions testing).

Let me know how you get on. P Garner is well worth speaking with re VAG cars, he's a fountain of knowledge on these.

 

[MasterAuron]

Regarding the silicone hoses, they are not needed on a fairly standard engine but highly recommended on a high performance engine given a constant thrashing. They withstand higher temperatures, split and burst less easily and expand less than the cheap hoses manufactures fit.

As for the rust....needs grinding back to bare metal, etch primering and respraying really.

Also question 6. As HDi said it's all done by the ECU these days. It's not a case of have 120bhp turn the boost up, get 180bhp. You're limited by the flow capacity of the turbo and there's a certain point where all you're doing is increasing inlet temps and not actually gaining any power.

Nitrous kits are very safe if used correctly. The size of the jet you can use safely will vary from engine to engine.

 

[pgarner]

As im not the most knowledgable person about cars, tuning etc ive always wondered the answer to some of these questions and hopeing they can get answered here, some of them relate to both petrol and diesel but as ive got a diesel thought id post in here.

1. Can i get my red line extended, eg from 4500 rpm to 5000 rpm ? just to allow the engine to rev that bit harded.

Yes but it requires the engine being balanced better and ot really required in diesels

2. Whats the diffrence between a custom and generic remap?

Generic is just a performance map thats just loaded onto the ECU. Custom is tweeked to suit mods already on the car

3. How safe it nitrous? ive heard now adays nitrous kits are very safe and only blow your car if you use it when your not supposed to. Also how much can you use on a 4 cylinder diesel engine?



4. Do performance exhuast or bigger exhausts, eg going from 2 inch to 2.5 make a big diffrence in power ? what about de cat pipes?

depending on how restricitve the OEM exhaust is then yes it can help free up power and on turbo models allow quicker spooling. decat pipes again remove the restictions however makes passing an MOT alot harder

5. When driving my car 99 % of the time my engine temp gauge is at the lwoest point like its not working. It does it when driven normal and hard. It will sometimes go up o 90 degree ( half way ) or sometimes just below. The car still runs the same and no warning lights. Ive heard this is something to do witht the radiator ?

sounds like the Coolant sensor is buggered mate very common problem on all VAG engines. you may also notice its drinking more fuel as it doesnt think its up to temp. bout a 10min job to swap

6. I was looking at putting a boost controller in my car. does this control how much boost you put through, eg set it to 100 bhp or then crank it up too 180 ?
Already been covered the VAG ecu is very sensitive and will go into limp mode if boost goes outside parameters. also the 130 tdi uses VNT turbo which adjusts the vanes to provide the boost

7. Is there anyways to stop a diesel from sounding like that diesel sound. I mean i dont want it too sound like a petrol just not like walking through a fairground.
non resonated exhausts are supposed to help

8. Whats the best type of air intake ? induction kits or panel filters ? I know induction kits cost more and sound terrible but is there a diffrence in bhp gain?
most diesel engines flow very well. CAI is generally better as its getting the cold air into the engine. however a smoothed airbox and clean panel filter help you slightly

9. When would you put silicone hoses in your car, you know thoses big coloured hoses, i think they look cool but there must be a real reason ?
already covered by MA less prone to splitting/colapsing under pressure

10. Is there anyway to get rid of rust once its through, or if its starting to buble through the paint ?
already covered

my answers are in red

 

[HDi fun]

I had a Montego once (come on this was pre 1990) which was plagued with fueliing and running problems. Simple temp sensor swap solved those immediately. Sadly, it was still a Montego so it had all the usual traits of those cars.

Even as a 2 litre (carbs, one only!) it barely managed 105bhp.

You can see how far things have progressed when even a modest 2.0 mainstream car is worth at least 150bhp now. The cutting edge diesel four at the moment is probably in the BMW 123d and that's good for 204bhp.

Bear in mind that this is the same as the original Ford Sierra Cosworth in 1985.

There's a Mitsubishi import around here somewhere with a 2.0 four (petrol) that's dynoed at over 350bhp. Substantially modified but it still idles at a rock solid 800rpm. Apparently the trick he used was to use two sets of injectors - a std set for normal running and a high flow set that cut in when the monster 2nd turbo started to heave itself into life.

 

[deedee]

So there's no point in getting the red line extended? I was just thinkin in the petrol vs diesel ( mapped ) race. An example could be the petrol car could be in 2nd at 60 mph when a diesel may have to be in 3rd possible even 4th so surly the petrol will win as it can get more speed in more gears? I've not yet had my car mapped but on a car that's had it done could a diesel get 60 mph from 2nd possible 3rd easily?

About the boost controller. I know someone who had one in his old EVO 6. He basically sayed he could controll the amount of boost goin through, or say max boost from turbo was "X" amount he could turn it down or crank it right up to max boost from the boost controller.

If it is the coolant sensor that's buggerd, will this damage my car or create any problems?

Also what parts of the engine suffer from reving the car high. Eg racing or just giving it a good workout.

 

[HDi fun]

Using all the revs is no problem if you keep the car well serviced and don't over do it when the engine's cold.

You cannot fit a direct boost controller to your car. PG and I have already answered this.

As for petrol vs diesel in a drag race I think you'll find that the diesel's ability to pull hard from 1500rpm will make up for lack of revs.

A friend with a 406 Coupe petrol (211 bhp 24 valve) put it side by side with my remapped 2.2 HDi and there was nothing in it from a standstill until over **mph, whereupon we aborted the test for safety reasons.

You PD150 should go to about 205bhp and over 300lbft torque.

 

[pgarner]

About the boost controller. I know someone who had one in his old EVO 6. He basically sayed he could controll the amount of boost goin through, or say max boost from turbo was "X" amount he could turn it down or crank it right up to max boost from the boost controller.

If it is the coolant sensor that's buggerd, will this damage my car or create any problems?
.

as said previously you can fit a boost controller if you want. but the ECU will through it straight into limp mode due to over boosting, if your turn the boost down the turbo will work hard to try and make the required boost by the ECU this could cause the turbo to overstress.

coolant - you may find it doesnt hold a steady idle, drinking slightly more fuel than normal and for around a £15 part you might as well fix it
part number is 059 919 501 A if ive got the right number here. if you ask at the parts desk for the green temp sender and retaining clip theyll knowwhat you want its a very common problem

 

[HDi fun]

You CANNOT mechanically control the boost of your car to any useful effect. It will behave as PG says, with the ECU making constant alterations to correct the situation.

Dashboard mounted boost controllers were the preserve of 1980's rally cars etc.

Go and get it properly remapped by Celtic Tuning. If you want less power and torque then simply lift your right foot off a bit.

Interchangeable maps are pointless for this very reason.

It's very simple, really.

 

[turbonutter69]

You CANNOT mechanically control the boost of your car to any useful effect. It will behave as PG says, with the ECU making constant alterations to correct the situation.

Dashboard mounted boost controllers were the preserve of 1980's rally cars etc.

Go and get it properly remapped by Celtic Tuning. If you want less power and torque then simply lift your right foot off a bit.

Interchangeable maps are pointless for this very reason.

It's very simple, really.

I'll have my 2 pence now. Are we talking about all Turbo'd cars or just Tractors?
You can control the boost on alot of Turbo'd cars. I know this cause I can control the boost on my Ti. IIRC Rover's 620 ti runs 11.9 PSI @ full boost. This can with the help of a manual boost controller be safely turned up to 14 PSI @ full boost. Most tend to back it off to 13.5 PSI. There is always a safe gap to turn up from standard boost until the ECU throws a fit.

 

[MasterAuron]

Dashboard mounted boost controllers were the preserve of 1980's rally cars etc.

Erm....not quite.

 

[HDi fun]

Why not just ramp it up with the ECU and keep everything else in a commensurate state of tune.

The gas pedal is a perfectly adequate boost controller for road use.

 

[pgarner]

I'll have my 2 pence now. Are we talking about all Turbo'd cars or just Tractors?
You can control the boost on alot of Turbo'd cars. I know this cause I can control the boost on my Ti. IIRC Rover's 620 ti runs 11.9 PSI @ full boost. This can with the help of a manual boost controller be safely turned up to 14 PSI @ full boost. Most tend to back it off to 13.5 PSI. There is always a safe gap to turn up from standard boost until the ECU throws a fit.

on older cars yes but on newer cars the gaps are normally alot lower. i know ines boosts to 10- 10.5psi (when its working properly) and 11.5 is max before limp mode.

the VAG diesels are more prone to throwing hissy fits as the bigger models were fitted with VNT turbos and diesels being the choice of motorway reps the actuator that controls the vanes quite often sticks causing all sorts of boost problems