Getting rid of lag.

[nickaudi41]

Hi everyone,

I was looking at another thread about lag and wanted to see what people thought about getting rid of lag.

I have a 2001 S3 with Revo SP2 and it lags up untill about 3000 RPM. What ways can I reduce this amount of lag.

I understand I could change the turbo but that's not what I want to do.

Any ideas?

 

[mwstewart]

Change the downpipe, or modify the N75

 

[nickaudi41]

Change the downpipe, or modify the N75

http://forums.audiworld.com/s4/msgs/1046677.phtml

This is an interesting link about the N75.

 

[nershen]

I've got a nice 76mm exhaust from the turbo to the back. That in my oppinion
made a very decent difference to the way the turbo spools up.

 

[nickaudi41]

I've got a nice 76mm exhaust from the turbo to the back. That in my oppinion
made a very decent difference to the way the turbo spools up.

I see, what exhaust are we talking about? How much was it, if you remember.

76mm is that 3"?

 

[Aky]

DPM has something on his site for about £200 which is supposed to eliminate LAG. Not sure how it works but I'm sure he'll be along soon to give the low down on it.

 

[steebo888]

rally cars use to bang bang system to eliminate this

http://www.rallycars.com/Cars/bangbang.html

 

[nershen]

Yep, 76mm = 3"

I paid R3200 (+/- GBP230) from a reputable fitment centre here in South Africa called TNT exhausts.

The cats have been removed as well.

 

[mwstewart]

3" Will be more than adequate for a K04, you will notice a difference with that fitted.

steebo - Both types of Anti lag are seriously harsh on engine components. Turbo's suitable for Anti-lag require a Maram shaft as the standard steel item doesn't last long before disintegrating.

The systems are effective but may of the teams are now looking to leave the system behind for reliability reasons. It does sound pretty sweet though

 

[jcb]

What ways can I reduce this amount of lag.

change down a gear?.....sorry, someone had to say it.

you are going to have to change your driving style or change some hardware.

new manifold, bigger block (2l is the way forward)

 

[ChriS3]

change down a gear?.....sorry, someone had to say it.

you are going to have to change your driving style or change some hardware.

new manifold, bigger block (2l is the way forward)

Absolutely!!!!!

All the other suggestions will change the delivery slightly, but it won't affect spool time. Increasing the block size is the best way, or a twin scroll turbo. Or install an anti-lag system (rally car style).

Exhausts will NOT make any difference to your power figures, nor will they change the characteristics of your turbo.

Besides, spool up by 3000rpm isn't laggy. What are you on about?????

 

[edward_harris]

That ko4 turbo spools up real quick! As long as your in the right gear i didnt even notice the lag!

 

[mattyboy199]

by the time you ve chnaged down a gear the turbo would have spooled up. Just drop a 2.0 TFSI engine in instaed (S3) best of both worlds minimum lag & extra power.

 

[QUATTRO_REP]

mounted on a street car a bang-bang system would destroy the exhaust system within 50-100 km

 

[DPM]

DPM has something on his site for about £200 which is supposed to eliminate LAG. Not sure how it works but I'm sure he'll be along soon to give the low down on it.

Are you meaning the Sprint Booster? That eliminates the throttle lag but not the turbo lag.

 

[jcb]

mounted on a street car a bang-bang system would destroy the exhaust system within 50-100 km

They destroy turbos, they only work on rally cars because they are rebuild every few hundred miles....added to which you would sound like a right c0ck driving round town!!

seriously..... 3000rpm? just choose the right gear when going into corners

 

[simch]

My IHI spools by 3000 revs...?

Sounds like you may have some boost problem there, if your k04 is not spooling until 3k.

What fuel are you running in your car, if ifs pinking it will pull the timing back massively and you will lose so much power lower down it will make the lag more noticeable.

Do you have an aftermarket Diverter valve...? It could be sticking open if so..?

A K04 should really be on solid boost by 2700 revs IMO
iifeelk

 

[nickaudi41]

My IHI spools by 3000 revs...?

Sounds like you may have some boost problem there, if your k04 is not spooling until 3k.

What fuel are you running in your car, if ifs pinking it will pull the timing back massively and you will lose so much power lower down it will make the lag more noticeable.

Do you have an aftermarket Diverter valve...? It could be sticking open if so..?

A K04 should really be on solid boost by 2700 revs IMO
iifeelk

I have a standard DV but Iwas going to get a forge DV.

I run V power through her most of the time.

She has also just had a service.

I have also posted on another thread this fault code.

16497 - Intake Air Temp. Sensor (G42): Signal too High
P0113 - 35-10 - - - Intermittent
Readiness: 0000 0000

I can't find out what this is, some say the MAF!!

Any ideas?

 

[jojo]

I hope you are differentiating the difference between boost and torque, max torque on an S3 happens around 3k revs, but boost will come in at around 1500, and build to max boost as it passes 2k revs... this is revving from 1500 onwards...

 

[simch]

OK, it looks like you have a problem with your IAT sensor, intake air temperature sensor!
Common fault, but can be fixed somtimes by cleaning it.

If yours is an s3, (assume so) look at the inlet manifold on the front of the motor. Where the rubber hose connects to it is the throttle body, just behind after the throttle body, on the front edge of the mainfold, you will see a black oval sensor. This is the IAT.
You remove it easily with one allen bolt. Its long, so be careful getting it out of the manifold, easy to damage it.

Once out, you need to clean it with some electrical contact cleaner spray, (halfrauds do it, so get some before you start!!) Dont tounch the sensor, its a hot wire sensor liek the maf and easy to contaminate it or break it. Just spray loads and loads of the cleaner on it and let it drip dry.

Then put it back in and refit it all.

The IAT if contaminated will make your fueliing go wobbly or even go back to base fuelling maps. It may be goosed, so if it does not make it better, you may need a new sensor.
While you are cleainnig in that area, I would recommend a throttle body clean, using tghe same contact cleaner spray.
If you search on here, you will see a good guide on throttle body cleaning.

Hope it helps, I think your problem may be fueliing or timing related, so fingers corssed the IAT clean will do it.

BTW how many miles and age etc is your car?i

 

[nickaudi41]

OK, it looks like you have a problem with your IAT sensor, intake air temperature sensor!
Common fault, but can be fixed somtimes by cleaning it.

If yours is an s3, (assume so) look at the inlet manifold on the front of the motor. Where the rubber hose connects to it is the throttle body, just behind after the throttle body, on the front edge of the mainfold, you will see a black oval sensor. This is the IAT.
You remove it easily with one allen bolt. Its long, so be careful getting it out of the manifold, easy to damage it.

Once out, you need to clean it with some electrical contact cleaner spray, (halfrauds do it, so get some before you start!!) Dont tounch the sensor, its a hot wire sensor liek the maf and easy to contaminate it or break it. Just spray loads and loads of the cleaner on it and let it drip dry.

Then put it back in and refit it all.

The IAT if contaminated will make your fueliing go wobbly or even go back to base fuelling maps. It may be goosed, so if it does not make it better, you may need a new sensor.
While you are cleainnig in that area, I would recommend a throttle body clean, using tghe same contact cleaner spray.
If you search on here, you will see a good guide on throttle body cleaning.

Hope it helps, I think your problem may be fueliing or timing related, so fingers corssed the IAT clean will do it.

BTW how many miles and age etc is your car?i

Sweet I'll try that this evening, thanks very much. The car has done 64000 miles. 2001 S3.

 

[simch]

I reckon it will need a clean, remeber to go to halfrauds on thee way home, its a halfords branded cleaner in a yellow can costs about £3.70!
the effect of the sensor being oiled up is it richens your mixture, and makes the car boggy, sluggish and use too much fuel!