Gary B

Hey all,

I've not been around here for a while but, 20 years on, I still have my RB5.

It's only been lightly modified during that time, here's a list:

Decat Down Pipe
ScoobySport Backbox
Greenstuff Panel Air Filter
Three Port Boost Solenoid
TD04 Hybrid Turbo (Andy Forest)
Brembo six pot front calipers with grooved discs
Suspension "stuff", mostly Whiteline kit, adjustable shocks.
Walbrough Fuel Pump
Apexi ECU
Map done by JDM - one of the last he did, may he rest in peace.

I never actually chose the Apexi ECU, I knew nothing of the product at the time it was fitted. My RB5 was one of the "WR Sport" PPP models and I wanted to retain (possibly to sell, never did lol) my Prodrive mapped ECU. The plan had been for Simon to provide a standard ECU on which he would add the new map. However, due to a faulty ECU, he offered me a deal on the Apexi. As I *had* to have things done right away - I'm sure many of you get that - I took him up on the offer & was pleased with the results.

Over the subsequent 10+ years the car has been largely fine, but I've always been aware of the weaknesses of the Apexi and how it'd often be the thing to hold me back. To summarise, while it's a great ECU, here are the main weaknesses as I see them, based on what I've been told during various mapping sessions...

1) It doesn't have any active knock control. While it can "see" knock, the ECU can take no action to retard timing if something goes wrong. This has led to a much more conservative map that what the supporting mods could, in theory, support. The car is de-tuned to a degree that it still runs well with old fuel to be safe, so doesn't really get the best out of good, fresh vPower for example. Hot weather running was also taken into account of course to keep the map safe. Happy it runs safe, sad it doesn't quite make the power it has the potential too - albeit with a large degree of risk on the Apexi, hence why I stuck with the safe option.

2) It doesn't have per-gear boost configuration apparently. I.e. you can dial in great boost (the hybrid turbo is good for 1.6 bar before it naturally vents) in the lower gears, then it'll overboost in the higher gears. This lead to a compromise so it's high gear safe, but it robbed much of its low-down grunt. It's still a quick car - even by today's standards - but it can do better. For a while, the car was mapped *without* this allowance for the higher gears. it was an absolute screamer in 2nd and third, but hard acceleration in forth and fifth would lead to boost-cut at 1.6 bar, so the map was toned down. As an aside, how the car performed on the Dyno vs. road was ENTIRELY different, hence my final "safe" mapping session was done entirely on the road. The boost cut never happened on the Dyno, but it did on the road.

3) It's an old ECU and newer ones are faster, have more cells to map etc. so can simply do a better job, when the two points above are also taken into consideration.

After a quick chat with Len at Subaru4You today - thanks buddy - we spoke about the Link ECU being a good progression on from the ageing Apexi. The Link ECU has active knock control, so things can be dialled up but remain safe. It can also be configured to have different boost characteristics per-gear, which should allow for the hybrid Turbo to really shine in the lower gears once more.

Basically, while the car does run fine, I want a bit more from it again while retaining safe running. From my brief conversation with Len, the Link ECU seems like it delivers and I'd be getting a Bob Rawle remap done.

What do you guys think? Does this sound like a good progression to get what I want? I'm not after some 400bhp monster, I never have been. I was always focused on a responsive build and the TD04 Hybrid definitely has the potential to deliver. I don't expect to see numbers much higher than about 300bhp and 300 lbs.ft - which is roughly where I'm at right now - but I do want that urgency back the car used to have while on the potentially unsafe, more aggressive map. While the power and torque figures were largely the same, the "unsafe" map felt so much more aggressive and fun. Better mid-range response and the car pulled harder all the way to 7k rpm. It was great. As I said, it's still very good, but has lost its edge for safety due to the Apexi's short comings.

Cheers.

G.

LewisScoob

iTrader: (5)

That all makes total sense to me. Link may also offer some addditional features such AL LC and FTGC

Gary B

Thanks. It made sense to me....but often what does, doesn't make sense to others so I appreciate your reply.

Oh, AL, LC and FTGC? I think LC is launch control (sounds expensive lol) but I'm not sure of the other off the top of my head. I've been away from all things tuning for a while now.

G.

LewisScoob

iTrader: (5)

AL - AntiLag
LC - Launch Control
FTGC - Full Throttle Gear Change

They're all gimmicks really but good fun here and there*

*if you break your car from this its not my fault lol

Gary B

Thanks. So, what's left for me to do other than hang on with those features enabled? Lol.

The car is naturally very responsive, so Anti-Lag isn't something I desire, nor feel the car needs. Also Launch Control...well, I like my Clutch - my *original* clutch no less - and I'm one for mechanical sympathy. Finally, Full Throttle Gear Change...driving a manual is a pleasure - my main car is an auto, albeit a very good one - and I'd not want to spoil that experience for a faster shift...and regular clutch replacements...and likely a new gearbox at some point.

I do LOVE seeing these features on other cars, but not on mine where I foot the bills

G.

The Rig

iTrader: (13)

Im in exactly the same boat as you Gary B but i run ESL, as good as it is and it does the job the per gear mapping is a feature i admire upon the G4 link ecu, like you, i could dial in some great boost for 2nd, 3rd and even 4th but a stab on the loud pedal in 5th created so much boost i toned it down, like you, not getting as much as i can from lower down, its 1 of those, how often do you scenarios to how that bothers you.

Id love the link ecu but at like £750 i cannot justify the cost for the small gains for a road car that i use daily ( 13 yrs and counting )

Gary B

I'm a little resistant to spending the money, and agree it's a lot when considering the relatively minor performance gains I'll get. However, to get that small potential gain as well as improve the longevity of the car might be worth it. Plus I have the urge to tinker a little, something I've not done in quite a while. I can hardly believe I've had the car 20 years years now, and it still drives so very well...if not with quite the urgency of that prior map.

I guess it plays on my mind a little that the tune is compromised, and I want it to run as well as the hardware can possibly allow. That said, I've not really had time to drive it much of late, due to it being in the garage having some rust taken care of and new suspension bushes fitted - which took an age to arrive. I need to get out and drive it properly over the weekend time permitting, then decide what I'm going to do. My hope is that Len at Subaru4You can provide the new ECU and fit it, and Bob can pop over from Swindon to do a remap. Not sure if my Apexi unit is worth anything, but it'd let me recoup some cash so it hurts a little less.

Also, from prior remap experience, even fairly minor changes to the peek figures can quite drastically change how the car performs. This gives that "it's something new" feeling in a way cheaper than a new car purchase does lol.

Oh, regarding Launch Control and Full Throttle Gear Change - I assume these features don't apply to my car, as it's not an electronic throttle, but an old-school direct link. My guess would be that LC and FTGC require the ECU to have control over throttle position to work...but perhaps I'm missing something.

G.

The Grift

Check out ECU Labs, I'm gathering bits for my my99 uk turbo and will be paying a visit to Richard Henry's in Bradford West Yorkshire where Andy Carr regularly attends mapping sessions. I'm not bothered about anti lag and launch control but will be going mafless and having a dual map.(High Boost\Low Boost) It can be supplied and mapped for less than the cost of the Link alone. ;-)

Just another option for you.

Gary B

Thanks, I'll add it to the list. Hopefully I'll get some time to do more homework on this over the weekend. I might drop Bob and email as he's the mapper Subaru4You uses and I've heard good things about his work. He might be able to offer further advice on the subject.

While I'm aware people run MAFless, I'm not really sure of the pros / cons of doing so. I know what the MAF does of course, so I can only assume that MAP is used if there's no MAF? I'm never planning to make big power, but I do want to make the best of the modest mods I've got. The car was so very responsive in the mid-range, with great pull to the red line in second and third with that older map and I want that back again, with the boost reduction in higher gears of course.

At the end of the day, I'm prepared to spend to get the job done right for my requirements, but equally I don't want to over-spend for ECU features that are of no interest to me.

G.

The Grift

I should have read your spec, the maf is prone to failure when you deviate from the standard air box setup, on the my99/00 years they are particularly fragile and a cone type filter can kill them. I see you are standard Airbox so it's not really a factor. Now if say you wanted to go front mount in the future but that's big power 400bhp plus you have to ditch the air box as there is just no room. Regardless of mafless I still think its a great ECU for our year car and the cost.

Gary B

Thanks for the tip The Grift. I'm unlikely to move away from the current air box and MAF setup currently as I'm not aiming for larger power levels. My understanding was that, with a decent filter, the standard air box on my model year should be ok for 350bhp or so, but not much more. I know people have gotten more out of them of course, but they've had more supporting mods than me. Oddly, I've only had the MAF changed once in the past 20 years, and that was after the original dealer did something to break it. I run a greenstuff panel filter that's lightly oiled and I've not had any issues other than that one unrelated one. So, I think they have the potential to be more robust than people give them credit for, if they're treated right and you retain the standard intake.

On my friends Hawkeye, we did use a proper Cone filter as we were chasing 400bhp. We made an insulated box around the Cone to insulate it from engine bay heat and revised the way the cold air feed worked. Made a measurable difference when we mapped it due to the better quality (colder) air. I'd not go Cone filter on mine without a few other changes.

Btw, I heard back from Rob Rawle and we're going to touch base next week and go from there. He agrees that the Link ECU - G4+ to be specific - should be a good match for my car.

G.