7a to a turbo conversion ? anyone done it !

[LEE HIDSON]

Hi, i am thinking of putting a turbo on to my Audi Quattro Coupe 7a engine. I have a WR Turbo 10 valve complete engine to use parts from. Has it been done before or can anyone give me some information as to wether its possible or not, thanx, Lee.

[Azman]

NOt with the 7A block and head, but if you wanted to go that route you would need to get all the EM bits and a turbo, a compression dropping gasket ala 034 motorsport to bring the compression down to that of the 3B engine, all the intake piping etc,

Here is a thought for you matey, (one I was thinking of when I get the spare cash and time) why not supercharge your 7A, get a pressure dropping gasket, run the charger off the bottom pulley, 3B intercooler or alike and some of your own made up pipework and bobs your uncle, the motronic should be able to handle it to perhaps with a remapp, also means that torque would be in lower down than a turbo too if tuned right

[Corey]

full thread can be seen here

This is one of 034's project cars that they have messed with.

[pastures16]

just buy an s2 its cheaper

[Puglife]

depends, my 90 20v was £180... engines a donor ofr SWB project... i'd be changing pistons, rods, injectors, proper efi etc, its cheaper to buy the full car with engine, swap bits over and have a powerful 20vT engine...
S2 engine is £1200-1500 to buy...

[Jamo]

S2 engine is £1200-1500 to buy...

You obviously don't know the right people! :mischeif:

There are forum contacts who i'm sure could get you one for less than that!

[mcandmar]

Engine can be gotten cheaper but by the time you add in all you need, wiring loom, ecu, intercooler, oilcooler, pipework, elecy bits, airbox, exhaust, downpipe, the list goes on and on

[BRY]

S2s start @ £1500

[LEE HIDSON]

Thanx guys, seems this one's a no go, although i will look into the supercharger idea !.The engine was going to be for my latest project, to take my WR a stage further. It's done in the group B livery and looks pretty cool but the engines standard, i just thought this might be an easy way of getting a 20vT.
So moving on, whats it going to be the ABY or AAN ?. So what mods are fairly reasonable and effective, I love Audi's and have got a few including a half built SWB with the screen conversion but like all projects i never seem the get the time or any help as im no mechanic. So this project seems more realistic at the moment. By the way, whats the differce between the ABY, AAN and 3B engines, im sure you all know.
Thanx, again...

[mcandmar]

Dont let us talk you out of it, anything is possible

In short all the 2.2's are the same bore/stoke, only minor differences. The real killer with the 7A is the higher CR, and the larger bore so you cant stick a set of S2 pistons in there and make it a turbo motor. Thats when the $$$ comes into play and makes a complete S2 motor the better option.

But, if your going to do a rebuild and buy a set of rods and pistons its the same difference really using either block.

For my conversion i bought a complete ABY motor, then chucked half of it away for a mix of 7A,3B,ADU, and custom bits. Probobly THE most expensive way to do it so dont listen to me

[Flat on my back]

Hit the Motorgeek.com site and check out what 'the man' at 034 Motorsport has done to a 7A block!!!

If your going to do a proper engine build, mechanicals and custom ECU you'll be replacing most bits from what ever you start with.

Cheap 7A or expesive S2 as the start, up to you.

Cheapest is engine swap then leave well alone.

[andy112]

Ive read on motorgeeks that the 7a head would have to be modded and I cant find what has to be done, anyone know? Also what are your guys thoughts on running te 7a block witha 3b/aan/etc head? What would the compression be?

[mcandmar]

7A engine has a single water outlet where it connects to the radiator, on the turbo engines there is a water manifold with 5 ports on the head all joining together, and then connecting to the radiator. Gives better cooling by having a port in between each cyl. So to use a 7A head you need these extra ports and bolt holes drilled.

ABY/ADU/AAN engines don’t use a distributor, mounting hole has a blanking plate bolted in. The timing sensor has been moved from the distributer hosing to the front of the head at the back of the cam pulley so there needs to be a mount machined for it when using a 7A/3B head.

Apart from those two points they are 99% the same and can be interchanged. Early 88-89 7A heads dont have all the stud holes drilled around the exhaust ports that are needed for the turbo manifold, post 1990 heads all seem to have them pre drilled/threaded.

7A block with 3B head would be the same, CR is dictated by the bore/stroke of the bottom end, all the heads are the same in that regard.

The difference with a 7A block is a 1.5mm wider bore, and the pistons have a flat top instead of being dished to raise the CR from 9.3 to 10.3.

[andy112]

^So by that Im guessing that using a 1990+ 7a block and turbo head would be easy, all I would need to do is remove the distributer. Also would doing a 1.8t coilpack conversion (http://www.s-cars.org/postnuke/modul...rticle&sid=191) like the urs4 guys do make this easier?