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Discussion Starter #1 (Edited)
Supersprinting Sprint. *Update 5*

*Edit* pics resized.

Here are a few photos of our ongoing Sprint track car project:

Engine so far:
40 IDF Webers
Rebore with 84.6mm pistons
Reground crank all new bearings
Race cams, unknown spec.
Adjustable cam gears
K&N Pod filters (I know.... more for ease of access than performance)
Baffled sump
Ported heads
Water pump removed, to be replaced with a Davies Craig EWP






Electronic fuel pump


Rebuilt gearbox


Suspension
Front 400lb springs, with re-valved Koni reds.


Rear 220lb? springs, re-valved Koni yellows


New rear drums etc.


Other stuff
33 16v Calipers for larger vented rotors.


Oil cooler and filter re-location blocks.


Rebuilt steering rack


More later. Questions, comments?
 

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Awesome looking project!

How did you get the gearbox casing and the heads looking so clean?

You may wish to reconsider the K&N filters as you'll probably find there is not a great deal of torque compared with even the standard airbox. I went back to the stock airbox from the K&N style filters. If you look at the old Alfasud "Trofeo" race kit option that Autodelta put out, you can just see the elbow shaped long trumpets - no doubt this was their trick to get a lot more torque from the 1.5L engine running 44 IDF's.

~Benjamin
 

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Discussion Starter #3
The heads and gearbox were chemically cleaned and painted with heatproof paint.

How much torque do you estimate the filters would lose over the standard airbox?
 

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The heads and gearbox were chemically cleaned and painted with heatproof paint.

How much torque do you estimate the filters would lose over the standard airbox?
Well it wasn't measured on a dyno, but it was enough to definitely feel the engine wasn't pulling the car as hard. Maybe 20-25% loss in torque. If I get my 'sud going again with the twin carb 1.5L engine, I'll be building long trumpets curved over the engine towards the front grille for cold air. That is always the problem with the 'sud/33 engine bay, there is bugger all room for decent air flow other than the radiator.

~Benjamin
 

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Discussion Starter #6
The body had just been resprayed in Alfa Bianco and im cutting it back atm. I will post up some progress shots soon.
 

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Discussion Starter #8
Crossover extractors, As far as I know they are an Australian made copy of the supersprint/ansa style headers.
 

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hey mate, sweet byuild up.... love the engine.... pity bout the diff the ailters make.... rekon they look heaps better... would it help if you put two smaller scoopsin the bonnet above the filters so the air rsn straight to them??

i am currrently rebuilding a sprint, and just wondering is the piston size you used standard???

cheers batesy
 

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Discussion Starter #15
Batsey,
I have seen the bonnet scoops your talking about on a sprint, I doubt that the way I have them set up that they would have any effect. I'm trying to devise way of connecting them to the trumpets that come with the standard air box. What budweiser_sud said earlier in the thread I think is a good idea i.e fabricating trumpets that face forwards. I really dislike having no air filtration so I think I'll have to compromise. As for pistons standard 1.5's are 84mm. If your rebuilding an engine its worth doing properly so I would say depending on how worn your motor is, it would be a good idea to at the very least get the bores honed and a set of oversize rings. That being said I would say a re bore and a set of oversize pistons is the best option. You could fit 87mm 1.7 8v pistons which would take the capacity out to around 1.6 I have seen this done with success but it is pushing the limits of a 1.5 block, so if you want the motor for an everyday driver I wouldn't suggest it.
 

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Batsey,
I have seen the bonnet scoops your talking about on a sprint, I doubt that the way I have them set up that they would have any effect. I'm trying to devise way of connecting them to the trumpets that come with the standard air box. What budweiser_sud said earlier in the thread I think is a good idea i.e fabricating trumpets that face forwards. I really dislike having no air filtration so I think I'll have to compromise. As for pistons standard 1.5's are 84mm. If your rebuilding an engine its worth doing properly so I would say depending on how worn your motor is, it would be a good idea to at the very least get the bores honed and a set of oversize rings. That being said I would say a re bore and a set of oversize pistons is the best option. You could fit 87mm 1.7 8v pistons which would take the capacity out to around 1.6 I have seen this done with success but it is pushing the limits of a 1.5 block, so if you want the motor for an everyday driver I wouldn't suggest it.

no worries thanks mate, good luck with the rest of it.... ill keep you in mind for any qs i have as i go... cheers
batesy
 

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What a nice job, well done. However I do wonder about the spring rates you are using though.

The front at 400lb as against the rear at 220lb, it seems almost the wrong way round. You might well find that you have more understeer than you want, when pushing it.

The old saying of "Stiffen the back to stick the front" (And vice versa) is worth considering. Or the alternative view of "soften the end that won't stick"

My 33 race car needs to be a lot stiffer at the rear to get it handling, and personally I would look at a softer front & harder rear. It took me several tries at changing spring rates etc to get the 33 going round corners well.

At the end of the day, your final choice is yours, and your setup will need to suit your intended use. Its whatever works for you, you might need to have a couple of tries to get the balance just right...

Cheers & best of luck !
 

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Discussion Starter #19
I've heard a lot of theories and talked at length with a lot of people about spring rates for suds all with valid points. After much thought we decided to go with what we have seen experienced racers use with success. If it doesn't work out as planned then we will start tinkering!
 
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