8vDigi - I want more response/topend.

[6foot6]

Hello all, So far I have brought my 8v Digi back from the grave and its now on the road and I have done a few trips to wales and back to London at some very silly cruising speeds and it has held up well no probs Revs and pulls clean. I have over hauled the Gearbox and fully serviced the motor.

I have also tuned the Digi via the Guide on this site (made very little difference) , now as this is the first Gti I have owned and driven Im not sure if it is as quick as one should be. I have a full scorpien exhaust, open filter with custom cold air feed pipe it just feels a little restricted at the topend (6K plus) which is no doubt down to it being a 8v motor ( im used to my twin cam 3sgte in the MR2 that revs to 8K and spins like a motorbike) .
what are my options.

Will a 16v head of a 16v gti fit and work with the digi EFi? (with a few mods no doubt) the AFM should be able to cope with the extra valves and provide the fuel ok, the old K tronic looks like to much of a PITA to swap over. In my mind swapping the head for a 16v seems to be the a easyer option than swaping in a 2.0 engine. Or how about a highlift cam?

My aim is for this to be my main track day car (whilst I over haul the MR2 engine in the autum) i really want more top end.

cheers,
Tom

[danny_p]

you chuck the digi 2 in the bin and fit dig3 if you abf

[6foot6]

Ok what the does that mean?
ABF = Engine code I take it?

Whats involved in swapping and why would I swap in the digi3? If im wanting a 16V head? or wanting the current 8v set-up to perform better?

[Diamond Hell]

Danny's suggestion is to pull out the 8V motor and fit an ABF (2.0 16v from a Golf3).

ABF runs on Digifant3 rather than Digi2 management, which is much smarter - there's no AFM on it and two knock sensors, among other features.

Fannying about taking the 8V head off and replacing it with a 16V head isn't worth it when you can pick up a complete ABF-powered car for less than £500.  These also come with a stronger cable-change gearbox, too.  This will pretty much bolt right up, although you need a Cordoba 16V o/s driveshaft as Golf3/Toledo 16V are wide track.  The cable-change gearbox diff is wider than the rod-change one, thus your current o/s driveshaft won't fit.

Alternatively, pull your current counterflow head off and fit a crossflow head from a later VW.  You'll get at least 15% better flow and because the inlet ports are on the front it's much easier to fit throttlebodies, if you really want to play.

[6foot6]

That makes sense. looms the same? or will i be soldering like mad?

[danny_p]

if it's 90 speck golf3 loom is plug and play

[6foot6]

I got a 88 E reg with the hazzard switch on the center console not the steering boss, so I guess it will be a pain.

cheers for the info, so Will the 16v head of a valver fit right up to the 8v block and will the digi 2 work on that?

Cheers again.

[Diamond Hell]

Quit it with the swapping heads already.

What's the point?  Buy a complete running motor instead and don't spend loads on head gaskets and head bolts 

[6foot6]

ok ok , but with the EFI in the 8v work with  16v lump (not 2.0 but a 1.8 16v from a mk2), donT want to be faffing about fitting old injection

[danny_p]

the head bolts up to the block thats it.  psitons often foul the valves and the CR you get is to low for NA use.  but you need to change all the pullys ( cam belt and accsesory ) then fit 16v pistons, also the 8v block dosent have the oil squirtrs that the 16v block has an it also has a smaller oil pump.

a 16v can be made to run on digi 2 but it dosnet work very well, digi 3  is much much much more advanced and fully mapable but will only work on ABF and other 16v's with 60-2 toothed wheel.   as for the wireing on a pre 90  you just have to swap the plugs over not  that hard