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ITB conversion for GTI

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I'd like to install ITB's on my Lupo and would like some help.

I purchased a donor car (2000 Polo GTI) to strip out drive-by-cable throttle body and pedal, so there is no turning back :)

This is what I need to know.

1.6 to 1.4 head conversion

I want to rev the engine past 8000rpm, and from what I've learned, the roller rockers will not hold. I need to ditch the AVY head, but which head will be the easiest to swap? I heard the water and oil ports do not match on a Lupo Sport head.

Manifold, Bodies, and trumpets

I contacted Bill at Badger5 to supply Jenvey throttle bodies, and I would like to know which size would best suit my GTI.

I am sure there are a handful of GTI owners that have considered ITBs.

If I succeed, I will document and post all the necessary parts that are necessary for the conversion.

Any input would be greatly appreciated.

Pics for views

p1.jpg

p3.jpg

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Depends on what other mods you have done or are doing at the same time, if you've got a set of cams in go for 45 IMO, if not stick to 42

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Depends on what other mods you have done or are doing at the same time, if you've got a set of cams in go for 45 IMO, if not stick to 42

Thanks for the tip joed05 :)

I currently have 254 Schrick cams installed.

Probably going to swap them for 280-290 cams.

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45mm would be fine for the 1.6, I plumbed for 40mm but if you are looking for a 8k monster 45mm would be ideal.

Inlet ports are a little weird on the Loop, 30mm spacing between 1+2 and 3+4 but only 20mm between 2+3

Direct to head is out of the question.

Did you get the diff installed?

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45mm would be fine for the 1.6, I plumbed for 40mm but if you are looking for a 8k monster 45mm would be ideal.

Inlet ports are a little weird on the Loop, 30mm spacing between 1+2 and 3+4 but only 20mm between 2+3

Direct to head is out of the question.

Did you get the diff installed?

Thanks for your input Tigz, much appreciated.

OK, so I am definitely getting 45mm bodies, with a DCOE manifold, both of which Badger5 will supply. I wonder if the port spacing is weird on the AFH head as well? I should be getting the head next week.

Yes, I got the diff installed last summer. Thanks to everyone (including you, of course) in the group buy!!

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Just contacted a Schrick supplier for the Gruppe H kit, which includes the 292 cams, valve, springs.

Anything else I should spring for? Will definitely port/polish, wondering what else I'm missing.

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Fly by wire/ pedal box?

Hi there, like I mentioned in my original post, I bought a donor car for the conversion.

I'm trying to figure out what parts I need for the AFH/AVY hybrid.

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I wonder if the port spacing is weird on the AFH head as well? I should be getting the head next week.

Yes mate, I'm afraid it is.

Yes, I got the diff installed last summer. Thanks to everyone (including you, of course) in the group buy!!

Mine's in, but the car isn't running yet.

How big a difference is it over standard?

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Yes mate, I'm afraid it is.

Trying to get a Sorg or VWM manifold, but none available anywhere.

Could always go custom, but I prefer the proven route.

Mine's in, but the car isn't running yet.

How big a difference is it over standard?

The difference is night/day on the track.

It is less noticable on the street, as it has a higher initial torque than some Peloquin-equipped R32's and GTI's I've driven.

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i have completly forgot what make!!!

its for an avy though so no use to you i just realised though haha

gary

Is it a DCOE manifold? Then it should work for all 16V small block heads.

Do you have pics?

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got told it was for the lupo but never offered it up.Is there a build thread on your car the arches look great but cant work out why

w7d28j.jpg

2it0s2h.jpg

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Right, so here is what I got so far.

AFH head

Schrick Group H cams, valves, springs, caps

DCOE Inlet Manifold

Will get the ITBs and trumpets/airbox once the manifold gets here and I measure clearance.

Running Motec as a standalone or piggyback.

Now on to the bottom end. I will get new piston rings and lightened crank and flyweel. I hope rev past 8500, just shy of 9000rpm to risk damage. Should I get forged pistons and steel rods? If so, where do I get them? Check Mahle and JE Pistons, none available.

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Wosner I think it's Spelt , Casper build thread will now be very usefull lol.

How much wad you valve, spring and caps? Have you though about who will do you porting etc yet?

Gary

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Thanks, but I think the pistons Casper got were to lower compression for his supercharger. I need pistons/rods that will maintain the same compression (or raise slightly)

The Group H kit retails for 1800 euros, I think. I get slightly better prices because I am a Schrick distributor.

There are alot of places that have a flow bench, and can perform a good port/polish, that is the easiest part.

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Right, so here is what I got so far.

AFH head

Schrick Group H cams, valves, springs, caps

DCOE Inlet Manifold

Will get the ITBs and trumpets/airbox once the manifold gets here and I measure clearance.

Running Motec as a standalone or piggyback.

Now on to the bottom end. I will get new piston rings and lightened crank and flyweel. I hope rev past 8500, just shy of 9000rpm to risk damage. Should I get forged pistons and steel rods? If so, where do I get them? Check Mahle and JE Pistons, none available.

Thats crazy on cast pistons, skirt speed is far too high. The pistons Casper had made were to std size, you could have the crown made 1mm higher and machine it to suit if you wanted higher compression ratio, which you probably do. you could also have a .5mm overbore on the JE pistons like the French guy did. wouldn't suprise me if you use very agressive cams that the valve cutouts would need increasing on th pistons... by this stage you need to look at steel rods, the rod bolts are only 5/16" and it will be expensive if it goes wrong at 9000rpm.

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Correct, my pistons were original size, small skirts so they will suit high revving aplications, but they will not fit original rods due to a larger pin being used, and a larger boss diameter.

I would think like james said that you will need to make the valve cutouts larger using a more agressive cam, there isnt much space up there.

Carillio do there CARR 5/16 bolt, which they guarantee will not fail before the rod they are built in to does. I have them on my rods, but there not cheap.... £18 per bolt when i purchased them.

John

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Thats crazy on cast pistons, skirt speed is far too high. The pistons Casper had made were to std size, you could have the crown made 1mm higher and machine it to suit if you wanted higher compression ratio, which you probably do. you could also have a .5mm overbore on the JE pistons like the French guy did. wouldn't suprise me if you use very agressive cams that the valve cutouts would need increasing on th pistons... by this stage you need to look at steel rods, the rod bolts are only 5/16" and it will be expensive if it goes wrong at 9000rpm.

Thanks for your response, I was hoping for some insight like this.

Ah, skirt speed.... you're right, I wouldnt want it rattling at high revs. As for the pistons, Id rather keep it at 1.6L so I will not go for a bigger bore. I do not intend to go cheap on this engine, as rebuilding it would cost more if something catastrophic happens. I prefer not to be sorry later. The problem is that I do not know where to get these parts.

Correct, my pistons were original size, small skirts so they will suit high revving aplications, but they will not fit original rods due to a larger pin being used, and a larger boss diameter.

I would think like james said that you will need to make the valve cutouts larger using a more agressive cam, there isnt much space up there.

Carillio do there CARR 5/16 bolt, which they guarantee will not fail before the rod they are built in to does. I have them on my rods, but there not cheap.... £18 per bolt when i purchased them.

John

Thanks for chiming in John.

I see, I always thought you dropped compression, I guess you used a head spacer. The valves cutouts may have to be widened anyhow, as I think the Group H valves are bigger.

I will send you a PM, hope you do not mind. I really want to build this the right way, you guys have been great help.

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Looking at the Polo I bought, I'm wondering if I could use the ARC block......

Looks the same from the outside, anyone know if the crankshaft/pistons are the same as AVY's?

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