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Does the 82mm tb upgrade reduce power???????

I really looking forward to finding out more about your progress on this Ken please keep us updated.

For us guys that like to mod their cars in the hope we can improve them but don't have the tools or knowledge to actually test them out in the real world, we are left picking through old post and the odd dyno chart while trying not to fall for the all of the over exaggerated advertised claims, so an actual tests and results from an expert would be a breath of fresh air, rather than the lottery we are normally faced with.


:popcorn: :popcorn: :popcorn:
 
Thefinn said:
I really looking forward to finding out more about your progress on this Ken please keep us updated.

For us guys that like to mod their cars in the hope we can improve them but don't have the tools or knowledge to actually test them out in the real world, we are left picking through old post and the odd dyno chart while trying not to fall for the all of the over exaggerated advertised claims, so an actual tests and results from an expert would be a breath of fresh air, rather than the lottery we are normally faced with.


:popcorn: :popcorn: :popcorn:
In our early days I can remember we thought that some aftermarket intercoolers were the business when tuning. Only until we got into real live datalogging did we find out otherwise. I ended up on four cars replacing those intercoolers with ones that worked foc.


The only way we put products onto a car for performance is if we can actually see a proper benefit on the road

Ken
 
Testing on the road has its own issues. I have some data showing a 20 degrees difference in intake temperature simply by turning the car around and going in the opposite direction. Don't test intercoolers on a windy day!!

MC
 
Based on the post and the fact that Wayne is a legend when it comes to tuning NA cars then I am not going down that route and staying stock plenum and Tb

Was going to do the spyder route

I might go 200 cell cats for better flow and leave the car alone
 
I have to agree with Wayne (he is brilliant) although sometimes it is very difficult to persuade other people to believe something they don't want to hear - to the point where it can not be worth trying (of which a choice of oils is a classic example).

It is so difficult to explain in a few words that I have been working on a comprehensive book on this subject due to be posted on our web site soon. One of the biggest stumbling blocks is that there has been over the last 40 years a general mistake made by almost everyone in understanding what makes a car accelerate fastest and so it is impossible to discuss the subject unless you can first explain the issues and then persuade readers to believe your own interpretation.

It is already over 30K words and 120 pages (including graphs, etc) and this is just because unless I cover all bases in my explanations - the forum will be full of never ending arguments that I don't have the time (or the inclination) to respond to.

Very briefly - tuning aids for a std capacity engines usually rely on shifting the power band upwards (at higher revs) and losing some mid range torque, often making the cars appear faster on paper (by quoting higher bhp figures and peak revs) but actually resulting in them being slower through the gears (due to the corresponding reduction in mid-range torque). This is because contrary to popular opinion, acceleration is proportional to rear wheel torque (not BHP) and rear wheel torque reduces in the same inverse proportion that the speed increases (or the gear ratio changes) so that as you change up through the gears the torque reduces.

Also you have to drive from the gears you start off at in each gear (after changing up) to peak revs and so the engine has to accelerate through a rev band in which the highest average torque will be fastest - but you can tweak the power curve to show more bhp at high revs but inevitably less average torque through the rev range.

The results often vary with the type of testing undertaken.


Bigger inlet throttle bodies are a classic example.


When carburettors were used the throttle had to have a venture to reduce air pressure (as the air speed increased) to life the fuel up from the float bowl to mix in the inlet - so the throttle body WAS A RESTRICTION and for racing (where low speed control and economy were not issues) would often benefit from larger inlets.


However fuel injectors do not need such a pressure drop so inlets can be designed without a reduced area. So - unless the throttle body is a restriction - fitting a larger one usually just does the same as a faster opening cam (wired throttles) because for the same foot movement on the throttle pedal the butterfly opens more and quicker - no different than if you were more aggressive on the pedal.

Similarly plenums and more open exhausts often fool the driver into thinking the car is faster when it isn't.

We have recently been working with a developer of new plenums who's own tests initially supported his design as more powerful but our tests didn't. after discussions between us - he has since agreed with ours under test conditions that are more similar to accelerating on the road and we are working together to try and find a genuine improvement.

Bigger inlets and/or exhausts result in it taking more time for the unsteady gas flow resulting from the engine speeding up and air flow rates varying - to settle down and so they may well flow more air if the test is conducted at fixed revs or slowly but be worse under fast accelerating conditions.


When dyno-testing customers cars, that have different inlet and/or exhaust systems, they are often (no usually) less powerful than the standard versions (Porsche knew what they were doing) but whatever state of tune your donor car is in - building an oversized engine eliminates these issues because it achieves both an increase in mid-range torque and BHP, better throttle response and acceleration (anywhere in the rev range) and results in a much easier car to drive fast without the need to rev it out all the time – reducing stress on mechanical parts and this is why we prefer this method of "tuning".

I am not saying you could not improve on Porsche's settings but you would probably need different cam timing and variocam settings to benefit from different inlet and exhaust systems.

Why this is possible is a big subject (and you will need a lot of experience and patience to follow our full technical explanations referred to previously when it is available) but the results are generally that with an oversized engine - the top end BHP increases in roughly proportion to the increase in capacity while the mid range torque usually increases even more than this (sometimes doubling that proportion in some areas).

The result is a general increase in mid range torque and BHP of around 15% to 17% and an increase in top end of 6% to 10%. Even when we convert cars that have been fitted with non-standard components (like noisy exhausts etc) where we often find them down on standard power to start with – the % increase after fitting the capacity conversions are almost identical.

As a result - we are reluctant to quote performance figures for our conversions because of these issues.

We are shortly posting a short report on our oversized engines on our web site that shows the test results from our engines and we have examples available for serious owners to test and see for themselves how much quicker they are (and the report in 911 and Porsche World confirmed this)

(a) We find that different cars of the same model often have slightly different output before we even start on the conversions.
(b) Different dyno-testing providers can end up with completely different results for the self same car.
(c) There are several different types of dyno-testing equipment (an engine dyno as used by Porsche, rolling road dyno's, axle dyno's and on board dyno's).
(d) There are different methods of dyno testing (fixed rev points, dynamic, inertia).

For maximum acceleration you need to first decide what gears are most important for your ideal performance. On track it might be 3rd and 4th whereas on the road it might be 2nd to 3rd and for autobahn work may be 4th to 5th etc and the time it takes to go from the revs you start at when you change gear to peak revs is an issue because of unsteady gas flow influences and combustion temperatures resulting from different loads..

If you run a fast inertia run it will not compare with a slower one in which the dyno is loaded to accelerate slower.

An engine dyno also usually results in different load and speed factors and all of them are subject to adjusting formulas that can uplift any result.

All the above provide quite different shaped graphs and figures. Indeed if you trace the graphs in the manufacturer's own handbooks over different 6 cylinder models and 20 years you will find that curves have become a simplified connection of straight lines and over the same period we have found that they have moved further away from those both we, Wayne and even the Porsche Club's motorsport's own designated test centre, find (while all 3 produce almost identical results to each other (ours being the same over 4K and very close to Wayne's under thos revs).

We are however happy to reveal before and after test results from our own cars – and customer rebuilt oversized engines.

So regardless of arguments about add ons - a Hartech oversized engine will provide improvements in both mid range and top end BHP and torque and therefore improves acceleration, driveability and all round performance far more impressively than most conventional tuning can achieve – and as a bonus – without over straining the engine and at a very modest cost if you are considering or need an engine rebuild anyway. However many other add-ons simply don't work or at least not as effectively as they are claimed to do.


Please don't bother to expect me to find time to answer disagreements on here right now - as this is what I have spent weeks writing the big article to achieve and it will do so when it is ready to post on our internet site.

After all this is just my take on things and others have their own - which is their right - but it might benefit you if you start working out who to trust.

Our Boxster and 996 engines despite being absolutely legal for racing have won the BRSCC championship, the Porsche Club Championship (and class 1 and 2) with excellent reliability. Wayne has similarly excelled in numerous tuning tasks for all sorts of models. You cannot achieve all this if you do not know what you are doing and furthermore you cannot cheat results if they end up winning races.

Baz
 
Excellent read Baz.

How is work on the 9a1 oversize engine coming along?
 
Although it would have been easier if we had discarded some features and it has been a lot more involved than the M96/7 engines, i am really pleased with the outcome. We have retained the oil spray jets, fitted the new cylinders and it is going together as we speak and should be running within 2 weeks.

As soon as it runs I will submit photos.

Baz
 
So gutted mine went pop before you were ready with the oversized 9A1 Baz, but do understand you needed to fully test the works car before offering the 4ltr up for sale.

looking forward to seeing the pics when the cars ready to run :thumb:
 

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