mike_nunan

Quick tip o' the hat to Bob and Branko (BRDevelopments). My STi4 saloon has been equipped with a VF22 since late summer, as part of a planned makeover that was to include some internal work and various other extravagant mods. I’ve been planning and researching, getting quotes and advice, and my eventual conclusion was that I would be spending way too much money going down this route.

However, I have had my car sitting there with a Link mapped for a VF23, even though I’d already swapped that unit for the 22. Something had to be done, and BRD kindly agreed to fit me in for a re-map at fairly short notice.

Since the fitting of the VF22, the car has been in for a month-long repair episode, and I have been away for another month on holiday, but the fact remains that last time I dared use full throttle was in August. Obviously, after all that time I was bound to be pretty delirious even with the old level of performance. So, without wanting to be too frothy, the following positive observations hold true:

1. Performance. There is definitely more mid-range urge than I remember, and the top end is much better. Bob set up my original Link map quite early on in his career, and took a conservative approach especially with regard to timing at the top end. I’m glad he did, as I’d sooner lose a few bhp than a big end bearing. Now, however, his additional experience coupled with the larger compressor of the VF22 have yielded a very willing top end. I haven’t had the chance to see how it pulls up to the red line in 5th, but judging by the 4th gear performance I am expecting big grins next time I have the chance to nip over to Germany.

2. Lag. This is weird. Yes, there is a little more lag with the VF22, but somehow it seems easier to “drive around” it, in comparison with the VF23. When the boost comes in it provides such as solid shove of torque that you cover ground very quickly indeed. If you spend a little effort on anticipating overtaking opportunities, you can really slingshot past on the crest of the boost transient. It’s quite addictive and much less frenetic than my old style, which would involve sitting with a balanced throttle at 4000 or even 5000rpm waiting for a chance to nail it. I seem to be using higher gears, and appear to be getting improved fuel economy (although this may be the “everlasting first half-a-tank effect” – we’ll see next weekend when I fill up again).

3. Bottom-end driveability, plus starting and idle stability. There are improvements here that have nothing to do with the VF22. I live in London, so traffic and speed bumps are constant obstacles. I prefer to hang back on a balanced or trailing throttle rather than drive on the brakes, so I want a nice linear response with a very narrow throttle opening at low revs. I spent ages (with my own tuning module) trying to teach the Link some decent town manners, without much real success. Having blamed this on various shortcomings of the Link, including over-coarseness of the timing map’s rpm axis, I must now eat humble pie and admit that Bob has done far better with his “standard” low-end map. It’s still not perfect by my standards, but I’m a ridiculous stickler and found similar problems with the standard maps on the last couple of hire cars I drove (a Megane and a Vectra – mmmm!!) so it’s a pretty fair result. There is still a weird jerk as the revs drop past 1500 on a closed throttle though, which Bob suspects might be something to do with the different routines that the Link uses in the idle zone (which starts at 1500rpm). There wasn’t time to look into this yesterday, but it’s not a major problem by any means.

Starting and idle seem predictable and stable, the only problem being the usual warm-start-then-stall behaviour that only the standard JECS unit seems exempt from. This sets in when the engine has been off for around 30-45 minutes. Hot starts and very warm starts (under 20 minutes) seem to hold, although a little bit of hunting is evident for 15 seconds or so in a will it, won’t it kinda way.

Anyway, that’s quite a bit of ramble for what was meant to be a quick thank-you note! To conclude, it’s clear that Bob is still going strong as the leading exponent of Link ECU mapping in this country. He seems confident to map more aggressively for performance than he did a year ago, and can produce a more civilised and driveable setup into the bargain. Definite thumbs-up from this owner.

TTFN

-= mike =-

davidaprice

Hi Mike

I saw your post on the BBS about Bob and the mapping of the VF22. I was interested because this is a mod I am considering for my Sti 5. I previously had a link mapped MY98 UK car and recently changed it for an Sti.

I already have a scoobysport downpipe, HKS Hiper exhaust, and all the link bits ready for fitment in the new year. The questio is whether I go the whole hog and get aVF22 as well. Any comments / thoughts / recomendations??

Also I notice you are based innthe London aresa. Unfortunatly before I have the above mods, I have to get my gearbox fixed, which is suffering from an apparantly commin(ish) complaint of crunching from 4th to 5th.

I wondered if you could recomend anyone in the London Area for such work??

Sorry for all the questions

Dave

mike_nunan

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