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My second Prodrive Edition 2.1L Stroker - GT35 - 500+ Track car
It’s 2022, Imprezas have gone up in value as much as petrol has . So it was time, after 6 years, to buy another modified Prodrive edition bug, learn from what the old one lacked and build on it to create something that is mildly nuts for track and road smiles.
This one belonged to a friend, and rather than buy it, I suppose I offered to take care of it in exchange for numbers in a bank account.
It has been in the wild for more than 10 years, north of 500bhp, and I will come back to that later..
2.1L Enginetuner stroker build on standard STI heads.
Lots of RCM bits
Rotated GT35, and etc.
Currently still makes 510bhp on v power, about 540 with a dose of meth.
Power wise it’s right there for me, so with that in mind, I am setting about keeping the same power, with less boost pressure and focusing on improving the handling of the car. My old one preferred to understeer, it was one of the lack lustre characteristics of a non DCCD Impreza that I didn’t like.
In general I love how it looks, though my partner doesn’t! I am working towards making it a little more ‘discreet’. Making a bright metallic blue Impreza discreet… might be a little tricky!
So, as I said before it runs over 500bhp, but it has been for over 10 years.
In February it still made almost the same power as it did back when it was first mapped by Martyn. Very impressive!
Its only downside, it uses some oil, which you notice when you start to drive it quite regularly, more than you would expect for road miles! Mind you, it’s doesn’t smoke or do anything untoward.
Some cooling problems cropped up, which was a number of things combined, the header cap was not working, but after sorting that, the header tank itself started to leak. Popping the new age hawk header on sorted the problems.
Of course, after a lot of testing on the road, it further exaggerated the oil consumption issues.
I set about removing the engine and opened it up to see what was inside.
*just a disclaimer, it has been running and enjoyed for 10 years at 500bhp, I knew the day would come for a rebuild, so a refresh when it was using some oil after this time period is an absolute win in my book!
2 & 4 cylinder bores had the worst leak down results, with what looks like oil being pulled past the rings, marks in the bores that can be felt and bores at upper end of their tolerance / a few thou oval.
Looking closely, the UK heads are cracked into the valve seat on the LH head (also 2&4).
Next step of the plan, after speaking with Andy Williams, he is going to take care of the engine and heads. Looking at a rebore with new pistons, with a general refresh.
While talking with Andy, we discussed the application, and the result was in addition to the block work, I would provide some complete JDM heads to have supertech valves, springs etc and light porting, to allow a little more flow to level the power at the top end, hopefully without losing too much spool down low.
JDM big port V8 heads arrived in mint condition from Jap performance parts.
With spool in mind, I am also going to fit equal length single scroll headers.
I collected the DCCD box from a JDM Impreza breaker, a DCCD spider pro arrived for dynamic control of the centre diff.
Lastly, I managed to pick up a new Link G4 with flex fuel sensor for mapping when this ordeal is over!
Hopefully, in the next month, I will have updates on the engine and will start plugging away at tidying the underneath and painting the engine bay. I am going to take the engine and heads up to Andy early next week !
Small update, I bought a Kakumai Spec C style spoiler for it, not exactly discreet, but I think they are a bit more subtle than the high level wing, and hey, it's adjustable too! I will look at making turn downs for the ends to make it a little more like the later S204 spoiler.
The reality if this ongoing project, it’s when I start propping things on it and planes appear on the roof that I know it’s getting bad .
This is how it sits now!
If you reading, you might be interested in some of the things that are going on here… I am not forgetting my goal, this is my take on an RA-R / Clubsport (with over 500bhp )
I purchased some very fresh WR1 subframes, which are being stripped and modified to correct the roll centre. Yes these are the kind of things that keep me up at night, if you don’t think it’s an issue, it probably won’t bother you, but the angle of the arms at my ride height is far from optimal. I just don’t have the budget for tubular subframes, not to mention the ride with pillow ***** etc are going to make it uncomfortable on the road.
Spec C RA aluminium bootlid fitted up, carbon kakumei rep spoiler might turn up next week .
I have neatly stripped and cut my prodrive front bumper. Awaiting a splitter to be modified to suit. Looking at tidying up the opening to the intercooler etc, it’s been hacked about a bit around the grill area.
I managed to find some APR wing mirrors for a reasonable price too .
I have been checking out wheels this week, I’m not keen on modifying the arches, but I would like some wider wheels! Looking for Turinis in silver .
I got properly back into the car today, made some progress stripping out the engine bay with components removed & got the spot weld drill out to remove the rusty lower rad support & brackets from the engine bay.
Aside from the typical lower panel rust, it’s otherwise clean in the bay.
Planning to get the engine bay all painted up in the next few weeks, after I take a trip down to buzz weld and find out what I need for the bay and the underneath!
Next on the list is get the rest of the running gear off the car and start eyeing up the cleaning / repainting underneath & then look at how to correct the front and rear roll centre.
Stripped out the rest of the bits and pieces with just some loom left to go.
Now that I can see where the majority of the fuse board wiring goes it might be a slight change of plan, will most likely reroute this to the drivers side. Part of the engine loom will have to jump across to that.
Few cheeky bits arriving, all not helping progress along in the slightest, but has to be done!
New roof vent kit & whiteline lower rear arms, drop links and the RC/BS kit.
Will be honest I’m not sure about the RC kit, I got it more just to see what it’s like in person - it has some RC correction, but no change in bumpsteer, apart from the ends seem to be re-angled. The arms look good for the money though.
I dug the Link G4X out and measured up / sourced the connectors for the CAN and expansion plugs. £40 each roughly to buy, but bought enough to make about 30 of them for £40! I already have the crimpers etc so it’s no brainer. Just needed to order some tefzel/mil spec cable and the JST-XA connectors. I will be fitting a DBW throttle and also hoping to use some of the ECU auxiliaries to do other things, like control an oil cooler fan for example.
So, long story short I want to get the engine bay exhaust parts ceramic coated (some for the second time around), so I set about just trying to botch the uppipe back into shape.
It is the older and arguably poorly* designed mk1 rcm kit. *it has lasted 10 years + though.
I welded the top and bottom flange joints and had the gasket faces resurfaced, thinking that would do.
I found that the wastegate takeoff was still cracked!
I set about getting some photos with the calipers in for scale:
I then set about designing a new centre section for the uppipe
05 April 2022, 02:24 PM
My second Prodrive Edition 2.1L Stroker - GT35 - 500+ Track car
. So it was time, after 6 years, to buy another modified Prodrive edition bug, learn from what the old one lacked and build on it to create something that is mildly nuts for track and road smiles.
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