Volkswagen Mark IV Forum banner

How to Tune a Normally Aspirated engine.... without wasting cash

Mk4 Golf 
Tags
mk4 golf
7K views 60 replies 23 participants last post by  biblejohn 
#1 ·
After a decent run on the rollers at awesome, where my car got
180BHP at the wheels, which equates to 220 BHP at the clutch a rise of
over 15 BHP more than many have had at various other well known
tuners......

Paul whos car was standard apart from a slight timing advance .75
dgrees got 170 at the wheels which fits with a standard 4motion.

  • Right what helped it breathe much better have done is
    performed the smoothed airbox modwith some 100 mm aluminium ducting and
    also change the standard cotton filter whenever its dirty (5000mile
    seems right). ?10 from halfords and B&Q
  • Also ensure there are no problems and the MAF is measuring air correctly and smoothly FREE
  • Advanced the timing 2.25 degress (dont take this figure as safe,
    learn a bit about vag com and check detonation etc before you do this)
    I performed this by using freeware Lemmiwinks and a cheapo ebay vagcom
    lead for ?25
  • Run on Super petrol only ?5 Extra a Tank
So all in all I got a 15 BHP increase for the sum of ?40 and a bit of
playing, so many peopl have payed ?350 plus vat to various tuners for
these gains that I well chuffed and have the opinion that anyone who
wants to tune a normally aspirated engine should follow this lead and
not waste cash on dubious chip tuning gains.

My next step will either be a de-cat or sports cats (they are too much
I think) just to help it breathe a little better, then maybe shcrick
cams

I should be able to get a 240bhp which would be well with the realsm of an R32 for less than a grand.......
 
See less See more
#2 ·
I'm sure the tuning firms that read and post free advice on this site will be chuffed you think that they are 'dubious' - Awesome especially seeing as they are the guys who ran your car on the rollers.

I am happy to pay - and will do - someone else to remap my ecu. I have several good reasons for this;

1. I don't know what I'm doing.

2. I don't have the equipment (laptop, rolling road, vag.com etc..).

3. Currently my time is best spent on other things than 'leaning abit about vag.com'.

4. If I wreck my ECU, I have to pay for the replacement.

I can see where you are coming from but you pay for someone's time, experience and warranty for their work.

Good luck with your car. Sounds like a nice project.
 
#3 ·
Hi Andy,

I'm interested in the advanced timing. This sounds like something I could do to my V5. I always run Optimax anyway. Thing is, I know nothing about 'timing' and have a limited knowledge of engines full stop. How would I go about trying this out? Also, do you tell your insurance company anything as it's not really an explicit mod, just a tweak? Also, is the cold air feed not a dangerous mod, following on from what happened to another member who got water in their engine?

Cheers,

Rye
 
#5 ·
On an N/A car the easy gains are gonna come from timing as Andy has found however if you change the cams then increased rev limiter is probably gonna be needed to get the most and to do that you'll need a remap.

For a cheap performance increase though Andy is spot on with improving the intake, sorting the timing and filling up with premium fuel. Using Optimax or similar along with the intake mods and suitable timing will see a nice improvement for around ?50 and if the timing is right the additional fuel costs would be negligable due to improved mpg, further gains could be had by adding millers to the fuel.

A proper remap would further improve performance due to the ability to map the timing curve throughout the rev range rather than a global change as made by lemiwinks/Custom-Settings.
 
#7 ·
Imported high performance Japanesse cars - STi's, Evo's etc.. - will run better on Tesco 99 as Japan has 100 fuel at the pumps. Fifth Gear did a comparrison test between Tesco 95, BP Ultimate and Shell Optmax, in three different cars. The Optimax gave the most power and torque out of the three but gains were only to be had in performace orientated cars. The clio they tested gave up no extra bhp.

I think this comes down to each individual car. Try testing the fuels back to back and see which one your car prefers. My APK 8v ran a lot better on Ultimate than Optimax - I am going to try a tank of Tesco's 99 tonight.

The garage that services my car routinely adds a fuel flush with each service so I don't miss the 'cleaners' added to BP & Shell's petrols.

From a different point of view the Tesco 99 petrol contains 5% bio fuels that come from renewable sources so by using it you are causing less harm to the environment!!!

Just my 2p worth.
 
#10 ·
Would i see any gains trying to tune my 2.0 8v
motor? i believe i may have a prob with my fueling as i return poor
mpg, i have had my lambda prob changed last month but tonight the
dreaded check light returned! N/A ggrrr!!
You need to do as we did to Nosaj's car, get it on vag com, and get
someone to log block 20 and do a graph of what the MAF (mass air flow
sensor is doing) (the CEL will have ;eft an error)

I reckon its either maf related or oxygen sensor or water tmpreture
sensor....... but get it scanned before you spend any money.

Once your sure its right, if you did the mods I did it probably see a 10% gain... so say 10/15 BHP
 
#11 ·
now why didnt you post this before i started to mod mine ...........[:D]

il be back on the rollers aswell once i get mine back from the
dealers (about a week) and will let you know if it was worth the money
or doing it the other way
Because I didnt know LOL I said at the time before I rollered it I
would be happy if was close to standard given the mileage....... so I
am very happy it has 15/20 bhp more
 
#12 ·
can any one tell me is tesco super 99ron better
or equal to optimax which is 98ron. it just more people seem to want to
use optimax of all performance fuel. cheers

myk3
I've used Tesco's 99ron a few times.

The first tank I used, i thought it was super amazing

2nd tank I bought didn't feel amazing anymore

3rd tank felt abit better than 2nd time.

Evo magazine did a test recently on all fuels, and concluded that ALL
high octane fuels (Optimax, Ultimate, Tesco's99) loose
power/effectiveness over time - therefore it's best to buy fuel thats
fresh - or put it a better way, only buy fuel from busy petrol stations
where u know the petrol is gonna be fresh.
 
#14 ·
I skimmed that review, how did they know how
long the petrol they used had been sitting around at the station
though? Or did they get it direct from the suppliers?
They bought the petrol from petrol stations - to keep the test fair.

I've left my copy of Evo in leicester - I'll dig it back out to see how
they came to that conclusion about fresh fuel being better
 
#18 ·
how do you know how many degrees is safe to advance the timing by?
You advance then log with vagcom to check your CF's in block 020.
I've had a look at that Lemmiwinks program. Looks fairly easy to use. So, is this something you have knowledge of Gary? What are CFs? Is this something that you could perhaps do at a local meet? [:p] Or wouldn't you want to risk it? I have no knowledge at all about this.. I could give you some beer tokens! [;)]
 
#20 ·
Lemmiwinks/Custom-Settings and Vagcom is all thats needed, its pretty easy to do.
We'll have a look at the next meet then, just fill up and continue to use Optimax or BP Ultimate.
Cheers! Looking forward to the next meet now. I always use optimax or BP Ultimate partly due to the performance aspect and partly because I get more miles out of tenner of optimax despite the fact I get less fuel for a tenner!

What about the Cold air feed guys? Is this not considered risky now that someone has experienced the hydraulic lock (water in engine)?

Also how would you inform insurance of advanced ignition timing? Or wouldn't you?
 
#21 ·
What about the Cold air feed guys? Is this not
considered risky now that someone has experienced the hydraulic lock
(water in engine)?

Also how would you inform insurance of advanced ignition timing? Or wouldn't you?
Don't drive through rivers then!!!!

I won't be taking mine off, if it worries you then stop the
intake ducting short of the front bumper grille so it sits higher up.

I doubt I would be calling my insurance company for timing advance, they won't have a clue what you're on about anyway!!
 
#23 ·
No offence and not meaning to piss on your fire but there really is only one way to do the timing and thats throughout the mapping.

Yes you can alter timing but it isnt as easy as just altering it and away you go.

You need to do it in 3d mode to make sure everything is perfect.

Here are some examples.

Posted Image


Posted Image


Posted Image


Posted Image


If you imagine the mapping as a square then all 4 corners must have a different amount of increase which is not possible unless using specific software.

Also if you image levels of advance it is easy to kill an engine quickly by altering too a bad level.

If you take a 2.8 bmw e36 and advance max of 9 degree, 3 degree, 3 degree, 1 degree this would make the car go like a rocket but do it too 10 degree, 5 degree, 5 degree, 2 degree and the engine will blow itself up.

Its an art to know exactly whats right or wrong but remember, modern engines are harder to hear detonation so unless you have correct tooling it is easy to make damage.
 
#26 ·
Rye - getting the timing right will see an improvment in fuel economy as the engine will be making more efficient use of the fuel.

Don't listen to ChippedUK's scare story, GaryM will only make changes to the timing in small steps (e.g. 0.25 of a degree) and will then log timing retard with vagcom to check that it is within safe parameters.

Yes a 'proper' remap will give better results throughout the rev range but even this method still requires logs to be taken afterwards to ensure safe running.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top