TeamSwift

just thought id do a quick write up of the swift im building up as a hillclimb car. was bought new by my g/f's mum in 1986 and used untill last year when the youngest daughter hit a roo near ballarat so it sat for another year before i was given the go ahead to turn it into a race car.

so far ive done:

tripple 36mm mikuni carburettors
custom exhaust, sidepipe
custom intake
custom remote thermostat
custom catch can
bigger mb barina radiator
kingspring low front springs
modified aftermarket struts
2nd hand rear shocks
2 inch lowering blocks on rear
rear anti rollbar off a mb barina retrofitted
stripped interior
avon race tyres, datsun stanza mags
overhauled brakes, fresh fluid
steeringwheel.

still on the to do list is a rollcage, harness and a run on the dyno to see where the mikunis are at tune wise. if it doesnt crack 75hp i might have to use the nitrous kit from my supra.

http://www.youtube.com/watch?v=SzttnTikeVw&feature=plcp

Great job let's see it in action!

great ob you done there, whats the top speed on the speedo clocks? whats its go like on them carbs?

good question mate, i honestly cant remember what the top speed is on the clock and im not at home to check.

yea carbs go great, starts fairly easy, i never even bothered connecting the chokes! it runs ritch at idle otherwise you get a lean spot when you floor the throttle, mid rpm is brilliant but high up it seems to be lacking although i think theres another issue somewhere else thats causing it. ive just taken the manifold off to properly port match it and put the nitrous and fuel sprayers in.

i also need to turn the fuel pressure up for the nitrous so ill have to see how the mikunis like that otherwise im going ot have to fit a 2nd fuel pump. ive been having a hell of a time getting the correct size steel for the rollcage wich is really annoying.

aiming for the first run to be a local hillclimb in november so im hoping to have it done by then (2 weeks holiday in japan before that tho)

also its got electronic ignition with a vacuum advance, anyone know how to retard the total advance on those while keeping the static advance the same?

Looks to be 180kph ~112mph

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1987 Chevrolet Sprint Turbo under construction

well as you can see ive had her at the local drag day, best we managed was 12.7 seconds on the 1/8th mile, how does that compare to everyone else? also got the half cage in her now.

still having trouble with sputtering going onto full throttle, it seems running the carbs pig rich solves it but otherwise it just wont snap open, i thought maybe the carbs are just to big for it so i made up restrictor rings inside the carb mouth and it seemed to help on snap accel but now it seems to taper power off a bit to early, im sure this is mainly due to the camshafts but it just doesnt feel right to me. also ive wound a shit load (14? degrees ) timming into it that seems to help keep it on the power.

the rear end is also a bit to weak in the springs, has anyone tried fitting harder springs from another model of car? thanks for the help eveyone.

At a guess, I'd say you need more accelerator pump shot. Thats if it stumbles under snap accel as you describe which only running pig rich improves.

trouble is the mikunis dont have an accelerator pump.

just thought id add a quick update, we ran this again at the locak 1/8th mile but this time ran it on e85 with no tuning at all and it loved it, now accelerates hard everywhere right through the rev range, ran a 11.2 second pass @58mph with no tyre warming. also changed the clutch with an exedy unit, couldnt buy a beefier one but this feels like its holding up fine. still yet yo use the nitrous oxide but meh its going fairly quick without it.

Looks awesome. Have you considered the grind motor?

What is the grind motor sobil?

I'd say autocorrect strikes again - maybe should have said GTi engine. If you find a GTI engine and close ratio gearbox ...... Keep the car they are in and build it instead.

New springs, an extra leaf or helper springs might tune up the backend. Not much else you can do.

I thought snowmobiles use two strokes engines. If the carbs are off a 'stroker, they will have different slide cutaway, jets, needles and maybe emultion tubes (which could explain your mixture). All easy enough to change if you have access to enough bits. Might also have an oil injection port you would have to block off. Old School Bike shop should be able to sort the carbs out. Been through seting up VM30 Mikuni's on a bike.

With the timing, I'd guess the ignition's all standard so nothing unusual. Best you can do without modifying the dissy is set the maximum advance to what you want and put up with where base advance starts. You should be able to set 34 max and 14 start or close to it. Set the maximum advance at the revs you want (you need a timing light that has an adjustment on it to dial in your maximum advance and it will show as zero on the timing marks when you turn the dissy to 34 degrees) and then see how much base you have.

Start at 32 degrees at 4000 and see how it goes. Then have a look at 34 / 4000. I wouldn't go past 34 degrees unless you're on a dyno. Even then, unlikely more advance is going to do much without a lot of other changes to the engine.

Jaycar sell a programable ignition kit that allows electronic programing of your ignition curve. It's a kit you have to assemble.

Once you start squirting NO2 into it - engine won't last long. The G13BA engines (crank and bearings in particular) were never designed to make any real power - about 50 HP if you're lucky. MK1 GTi has a different bottom end, fuel injection and starts at 100 HP at the flywheel. Couple that to the close ratio gearbox and you have a completly different beast. What you have is fun till you push it too far then it's rebuild time. For what it's worth, might be better leaving this car where it is (the development of it) and finding a Mk1 GTi to build up or transplant the GTi running gear into your current shell. GTi transplant means you still have the leaf spring rear to sort out.

Another point - put a vacuum gauge on the dissy vacuum port. Should be around 20 at idle. With the 4 carbs might be low so advance won't be doing its thing properly.

Yet another victim (this thread) of disappearing hosted pics I'd liked to have seen.

Something like PostImage.org which has a "mod" for phpBB forums that lets a poster upload his pic from within his thread reply window, would be a nice convenience.