Andy Williams from Williams motorsport and myself Graham, (EngineMapper) have teamed up to produce hopefully an epic test mule.

Andy bought an 03 WRX not long ago with a knocking bottom end which he was originally going to fix and sell on. Que my arm twisting and inspirations and he has the engine in bits and is forging it as a start of the epic test mule that we both want to play with!

The idea behind the project is to start off with a completely standard car from which I will benchmark power test and map throughout whilst testing common modifications Impreza owners want to make, their performance difference, improvements and cost-to-performance benefits. We will hopefully go from a standard car that produces 220bhp approx all the way to the upper limits of the top mount capability and perhaps up-wards of 500bhp ultimately proving components that he or I want to develop or test as well as commonly made modifications.

We want your input! I'm particularly interested in the common mods on a standard car, i.e showing decat d/p, u/p and exhaust improvements, air filter/induction kit, fuel tests and such like. But I want to know what you want us to test! Within reason of course. Lets mythbust some stuff!! Ebay turbos?

So currently the engine is being rebuilt. As a strict rule I've dictated that it must start off as standard compression and standard ancillary setup, e.g, TMIC, TD04 etc etc. We agreed on using forged internals on the basis that it will get a lot of torture and ultimately I'm not interested in testing the internal limits of the engine. So it has been blessed with Mahle pistons, Williams forged rods, ACL bearings and MLS gaskets.

Performance differences and mapping improvements will be measured on a Gtech Pro power test for graphing as well as timed acceleration tests and perhaps 1/4 mile for definitive comparison. Dyno testing will most likely be included at key intervals of the test regime to solidify results that I get on the road.

 

this sounds like a great idea. looking forward to some results.

 

This will be a good read, subscribed. Bear in mind though that even over enthusiastic DIYers like me are managing 600+bhp driveway builds these days

 

Sounds like a good plan and read

Andy

 

That's a great idea Graham, people will be able to rely on hard facts before spending their hard earned instead of relying on manufacturers "claims".

Very gallant to put your own time & effort in to this. Good on ya!

AJS

 

Hopefully it will be useful and insightful for others and a bit of fun at the same time!

it's true, 600bhp now seems like common nature. However the key in this project is not peak bhp or anything along those lines, it is to answer the key questions that the forum gets littered with everyday. 'Should I decat my car? Do I need an uprated fuel pump? etc etc'. Obviously some things can be universally applied to other models and other things will be specific pitfalls of this year WRX which I hope to make clear when writing a post about a test that may have taken place on it.

Thanks for the good comments though! Please feel free to come up with some test ideas!

Graham

 

Hat off to you Graham, I'm sure your posts will benefit many on here, myself included.

Good luck with it all

 

Great post can't wait to see results

 

Really good idea and very interesting to see what result differences you get between mods.

 

Sounds good
Will be a great thread!

 

Brilliant idea looking forward to this one

 

I would be quite interested to see if changing the panel filter actually gives some more horses as it seems to be the most popular first mod anyone does.

 

This is definately one of the tests on my list of to do's for sure! Though I suspect the filter is a proportional gain to the amount of air flow the car pushes. I.e gain would be a higher percentage at a higher throughput of air flow. I will probably try this as a first test on a standard setup, then switch back once more mods have been done to see if the proportion of increase changes.

Graham

 

Interesting

 

Sounds good, it would be interesting to see what some of the more subtle changes such as ported headers or TGV deletes would do for the power and torque

 

Excellent idea Jon, not sure I could convince Harvey to lend me a set of ported headers for direct testing, Harvey?? But interesting idea, definately going to try a new set of headers on the car for sure and justify the headers we will use potentially.

Graham

 

Shame you are so far away otherwise I could have considered lending you mine that were ported by FB Tuning, would also be interested on the real differences between equal and unequal headers, and simpler how much difference wrapping them makes

 

Wrapped and un-wrapped is a cracking idea. I think ebay vs roger clark or such like would be a fair test if I can get hold of some. Equal vs unequal is also a good one, the only issue is what make of headers to use or do we try a whole heap of them? Part donations definately necessary!!

Graham

 

sounds good, can i also sugest you take the opertunity to test some back to backs on similar products as you go.

eg, you decide next mod is headers, try a few different ones, then the final 'best performing one' try some mod's to that, say no heat wrap then heat wrap.

 

Back to backs has to be on the cards, but how much depends on whether I can get hold of bits and pieces to test.

Any other test ideas?

Graham

 

Hi Graham
Test idea for you back to back

Perrin turbo inlet hose . On perrins 08 sti test car they said it improved spool up by 250 rpm due to less restriction and it gained 10 bhp top end ?(without map change )

Andy

 

Final 1st engine spec for the project car-
Open deck block
Wossner Pistons 8:0-1 Compression
Std used (85K) Crank
Williams Motorsport H beam rods
ACL Race series main bearings
Mahle Racing series big end bearings (Prodrive WRC engine spec)
Std used oil pump (84K) tweaked for estra pressure, go on tell me I'm crazy not to fit an RCM Cosworth unit.......:-)
Cheapest head gaskets I could find....ebay £39.00 a pair.....yep I'm still crazy!!
The engine is otherwise std.

Very interesting to see the comments and ideas coming through, and we will try our best to check out as many as we can as the project unfolds. I chose to build the engine with decent rods and pistons as the car will be punished and as it needed a re-build I wanted a strong base to start from.
Ive used a std old oil pump as this is a myth I would like to challenge from the start, I believe the big end problems associated with these engines has little if anything to do with the oil pump or the crank......I guess we'll find out soon enough?
My ebay uprated clutch has just arrived so I'll go and pop the engine in.
Back soon...........Andy

 

Sounds like my kind of build

 

The engines now in and running, ive filled it with some 15/40 mineral oil to bed the rings in, after a few cranks to get the oil around it fired up with no problems......phew! Ive a few things to do and all being well i'll get an mot this week and get a few miles on the new engine.
The plan will be to re-map on a complete std set up, then start trying some minor things, any suggestions on what to do first, air filter, up-pipe, down pipe?

 

As the air filter is the easiest no-brainer for anyone to fit maybe that should be first in line, then back box.

Cheers,

AJS

 

Be good to see how this progresses - and hats off to your builds, Simon (JGM) commented it was one of the quietest 2.5's he'd ever heard while mapping it through the Det cans.

 

While doing all these test I would do a comparison with standard part against upgrade so get max power out of map with stadard part then use the aftermarket part so we can see if the are any gains to be had from each part. few parts I`d want to see changed would be

1. Panel filter 2. Back box 3. Back box and centre section etc all the way to down pipe inc decating second decat then sports cat in the down pipe the decatting this 4. Up-pipe 5. Fuel pump 255 or other 6. 3 port boost solenoid 7. Sti intercooler 8. Silcone hoses 9. Induction Kit 10. Different Injectors 11. Range of different turbos ebay vs standard td04 td05 vf range etc etc 12. dump valves/recircs 13. Front mounts

I`m sure theres a million and one things you can do but Id like to see these tested as its the route im going down and one alot of us go down with out a limitless pockets of spondooly.

Rich

 

Thats exactly the idea behind this project, we won't be able to try everything out, but we should be able to test enough to show what does what at each level of tune. Their are many ways to skin a cat and every tuner will have their own ways of doing things of course.

 

Great stuff, what about different grade fuels ?

 

Hi Andy and Graham ,this is a brilliant idea and will benefit many people.
Hope some dealers get behind you to supply you with some parts to try ,
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