Performance Tuning Myths
 

Hi all,

We get a lot of customers asking various questions about performance modifications. I thought I would take this opportunity to dispell some common performance tuning myths that we often hear about. So without further ado, here is a list of the top 10 (yes there are more!!!)...

Myth 1. You can't get more than 300 bhp from the T5.
Truth - This is totally untrue. You can get well over 300 bhp safely. Pump fuel is the biggest limiting factor determining the amount power you can run. The engines can handle about 350 bhp safely before you start to run into problems.

Myth 2. You will bend the con-rods running more than 1.2 bar.
Truth - Again, total rubbish. The T5 engine will take over 1.4 bar boost before things start going pear shaped. Many engines can take more than that, and the newer ME7 cars have been known to boost at 1.8 bar for short periods without damage.

Myth 3. You need a cat-back exhaust when upgrading the ECU.
Truth - Not true at all. Sure, it may give you a few extra bhp (5-10) if you're lucky, but it is in no way required!

Myth 4. My turbo will run too hot if I don't fit a sport exhaust.
Truth - Not true! The cat-back exhaust does not determine the temperature of the turbo charger.

Myth 5. Why should I upgrade my ECU when I can just fit a bleed valve.
Truth - On the pre ME7 cars, you can run a bleed valve but it is a VERY crude method of tuning. The bleed valve does not address any fueling and ignition issues associated with the higher boost. That is why an ECU upgrade is the recommended method of tuning. On the 1999 and later ME7 cars, the bleed valve won't work!!! Eventually the ECU will throw an engine check light. On these cars, the only way to get increased performance is with an ECU upgrade.

Myth 6. You should fit a stronger actuator.
Truth - Bad mistake! Unless your standard actuator is faulty, leave it. This is your safety valve against running too much boost. Also, you should let your boost control solenoid regulate the boost, so don't disconnect it. We have seen cars fitted with 2 bar actuators, which is a sure path to engine destruction.

Myth 7. Fit an induction kit for more power.
Truth - Doing this will lose power! Why? Because you will draw hot air from the engine bay, which will result in lower power.

Myth 8. Run a bleed valve with an ECU upgrade.
Truth - Never ever do this!!! A proper ECU upgrade increases the boost, and running with a bleed valve will be dangerous. A correctly mapped ECU upgrade will not need a bleed valve.

Myth 9. My CAT will melt if I don't fit a cat-back exhaust with an ECU upgrade.
Truth - A blatant lie! Ignore such claims as it is simply a scare tactic used by your exhaust supplier to sell you a cat-back system.

Myth 10. Fitting bigger injectors will give more power.
Truth - Wrong! Running rich will give you less power, unless you have more air. And even then you need to get the mixture right. Run too rich and you foul plugs and loose power. Too lean and you run too hot and loose power. Fueling is the most critical aspect of performance tuning and should not be messed with unless you know what you are doing. Correct fueling when tuning will determine how long your engine lasts!

There are loads of other myths, too many to list. But if you want more info, call us or email us!

Adam.

RE: Performance Tuning Myths
 

Thanks for that chaps. Would you consider writing them all up for an article in "Technical Driver"? If so and you do please send the article to Jack Cluer the editor of "Technical Driver" or submit it to Bob Isaac for inclusion in our FAQ pages.

All the best, Peter

RE: Performance Tuning Myths & a question from me
 

That was really interesting! More, more!!

How do the 850 T5 autos hold up to chip tuning? Yes I know I`ve only had it a week! :D :D

Big Lee

RE: Performance Tuning Myths
 

Surely 7 is open to debate?, as long as its well fitted and the cone boxed in from the engine bay in order to ensure cold air, power can be gained.

RE: Performance Tuning Myths
 

But then you effectively have the same setup as the stock airbox!!! So why bother with a more expensive cone? Besides the stock air box is not a big restriction. It's good for at least 300 bhp at the wheels.

Adam.

RE: Performance Tuning Myths & a question from me
 

They hold up perfectly. No problems with the auto tranny.

Adam.

RE: Performance Tuning Myths
 

We would love to! We have lots of interesting technical stuff that we would be more than happy to share with the VOC.

Adam.

RE: Performance Tuning Myths
 

OK Adam and thanks for your kind offer.

All the best, Peter

RE: Performance Tuning Myths
 

Adam,

Thanks for posting the myths. I have spoken to you after 2 or 3 other chip re-mappers and the total situation within the aftermarket tuning business is competitive confusion. Confusion is increased by end users who are less than complimentary with failure to see their expectations realised. Throw into the mix the never ending dispute on petrol quality and potential customers are confused every which way :)

When I spoke to you I remember that you advocated that Optimax would ensure the best results but a slight problem is that the nearest Shell garage is 7 miles from me, in a direction I never travel. However the new BP Ultimate is starting to really make a difference in the car I use mainly (Peugeot 3.0Ltr coupe) and I suspect that when a few tankfuls go through the V70 T5 it may reflect the better than Optimax edge that I see in the Pug. Any comments?.

Another off-putting factor is that Bromsgrove is not far short of 180 miles from me which as a one-off wouldn't be a problem but my car has been hooked up to Vadis 5 times in the last year and at least twice a total download has taken place (Maff sensor once, Keys re-program twice, O2 sensors twice). I guess you would have become more fed up with me returning for re-program than I would with the 360 mile round trips ;)

As soon as a local (Surrey) dealer gets on board and once I am convinced that my recent O2 problems are history I will become a long distance customer.

Traduk

RE: Performance Tuning Myths
 

Hi Traduk,

If you could email or pm the details of the Surrey dealer I will get on the case. As for the petrol, well the rule of thumb is that the higher the RON, the better. Be it Optimax or Ultimate, as long as it's the highest RON you can get then you will be ok.

Interestingly, yesterday we had a C70 on our dyno which demonstrated nicely the problem with 95 RON in a tuned car. Sure enough, 95 RON can NEVER EVER achieve the power levels in an ECU upgrade designed for 98 RON. After 4000 rpm, the boost and ignition had to retard to reduce knock, and the fueling is richened up by a huge margin for extra cooling and safety, and most of the power gain is lost!!!

Don't get me wrong, the car will run fine on 95 without problems, but the max power will be down by about 30bhp. The difference really is that huge, especially when the car is driven hard.

Adam.