I need to make just <120 BHP from anything fitted to a Mk 2!

[JonLeeper]

The short story is this:

I have been working on a Track Slag Mk 2 for a while, see http://www.golfgtiforum.co.uk/index.php?topic=130170.0, and have just moved to Gutersloh where I have found a cheap race series that i could join.  Some more info www.rallyx.de.  Due to the rules I want to remain (just) under 120 BHP, to stay in Class C, but must use an engine that was originally fitted to the Mk2 without much modification so head ports, lairy cams, etc are out.  So I could use a G60, but that would develop too much power and push me into the unlimited class, not where i want to be just yet!    I currently have a 190,000 mile 8v fitted so am probably struggling to break 100 BHP!    What are the options and which gearbox should I be looking for?  Funds, as ever, will be tight but I am willing to do a lot of spannering myself.

Current thoughts are a completely rebuilt 8v which should see about 110 BHP.  With a little fettling, by which I mean a little matching of manifolds etc and a free-flowing inlet could be an easy solution.  I was also thinking that a 2.0l 8v bottom end with the 1.8l 8v head would release a few more horses without going overboard.  It would, hopefully, not be noticed and should sit just under the required 120 BHP. 

As for gearboxes I am totally unsure.  The track used is part of an airfield and so does not have lots of long straights but does have a couple of tight corners, or the set up they has yesterday did.  Looking at the available real estate it is unlikely that many of the races could have long straights so I guess I am looking for shorter gearing, or is my stock 8v fine?

All advice / comments gratefully received as I have until Christmas to come up with a plan and get hold of the necessary bits before moving the car to Germany in Jan and starting preparations for the first race in about March.

[rob.043]

Would a mild cam/4branch and re-fuel mapped 8v not be tapping sufficiently on the door of 120bhp for little money, and standard ratios should be ok. Could drop the final drive a bit maybe if the tracks speed is below 100mph, (a standard 8v box would be doing an indicated 120mph at 6000 rpm in 5th)

I dont feel that these old VW engines in good health deliver less BHP than their quoted new figures, as the saying goes, 'old dubs dont die, they just get faster'!  so it should not take much to lift an 8v to 120....

[danny_p]

take an 8V gti lump,  rotaionaly balance the bottom end,  ( won't really make it more powerfull may gain 1 or so bhp but it'll stop it blowing up if its been raced )  lighten the flywheel as much as possible ( 020 flywhells aint that heavy tho to start with ) 

baffel sump  fit windage tray,   then piss about with airbox , filter , manifolds and exhaust it should find 120

[VeeDubGTI16v]

build a 10k rpm 1.3 screamer!

[JonLeeper]

Would a mild cam/4branch and re-fuel mapped 8v not be tapping sufficiently on the door of 120bhp for little money, and standard ratios should be ok. Could drop the final drive a bit maybe if the tracks speed is below 100mph, (a standard 8v box would be doing an indicated 120mph at 6000 rpm in 5th)

I dont feel that these old VW engines in good health deliver less BHP than their quoted new figures, as the saying goes, 'old dubs dont die, they just get faster'!  so it should not take much to lift an 8v to 120....

Would love to play with cams and manifolds but the rules state that these have to remain standard.  I think that \i would get away with porting out the manifold to match the head but that would be about it.  I am glad to hear that you don't think that old engines are that far down in power and that standard ratios will be fine.  I may just have to play with it then.

Many thanks,

Jon

[JonLeeper]

take an 8V gti lump,  rotaionaly balance the bottom end,  ( won't really make it more powerfull may gain 1 or so bhp but it'll stop it blowing up if its been raced )  lighten the flywheel as much as possible ( 020 flywhells aint that heavy tho to start with ) 

baffel sump  fit windage tray,   then piss about with airbox , filter , manifolds and exhaust it should find 120

What would i pay to rotationally balance all of the internals?  I have not looked into it so is it expensive?

I was thinking that I would remove one of the headlights and duct a direct cold air feed to some form of free flowing airbox, possibly K&N type cone in a box.  Windage tray is on the cards, the diesel had one I believe, so will try that.

Thanks,

Jon

[JonLeeper]

build a 10k rpm 1.3 screamer!

Which 1.3 VW engine fitted to the Mk2 did you have in mind? 

[Khare]

If I was in your position I'd take the engine out, put a fresher engine in with lots of service history (mk2 8v engines can be found for sub £100), lighten flywheel, sort airbox, put cold air intake, baffled sump, give it a nice service and take it to a dyno and see what it puts out. If remapping is allowed then get a custom remap to get it as close to 120hp as possible. Even some ebay chips have given dyno proved 6hp on ABF engines, I'm sure they'll give 3 or 4hp on an 8v.

[danny_p]

on a mk2 digifant you cant alter the spark tabels,  and the spark tabels are where the power is hidden,    in over simplified terms you tune the fuel to allow you to get the spark advance on,  all you can do with the DF2 ecu is just wind on the static advance from 6 degrees to about 10 degrees with good fueling that gice a bit more power when it's revving  just make sure the knock sensor is healthy as it will be useing it.

rotaional balanceing costs about £120 iirc

[rob.043]

 

Hopefully a standard gearbox will suffice, if you can

Would a mild cam/4branch and re-fuel mapped 8v not be tapping sufficiently on the door of 120bhp for little money, and standard ratios should be ok. Could drop the final drive a bit maybe if the tracks speed is below 100mph, (a standard 8v box would be doing an indicated 120mph at 6000 rpm in 5th)

I dont feel that these old VW engines in good health deliver less BHP than their quoted new figures, as the saying goes, 'old dubs dont die, they just get faster'!  so it should not take much to lift an 8v to 120....

Would love to play with cams and manifolds but the rules state that these have to remain standard.  I think that \i would get away with porting out the manifold to match the head but that would be about it.  I am glad to hear that you don't think that old engines are that far down in power and that standard ratios will be fine.  I may just have to play with it then.

Many thanks,

Jon

If you have to run standard cams, on a standard engine, with a max of 120bhp, then they are at least aiming you squarely at using an 8v GTi engine.... So the above balancing/intake advice should be enough to coax a healthy engine a little closer to 120bhp within the regulations.