Audi 90 (1985) type 85 with 7A Conversion

[Ryss]

I am nearing the end of a low budget conversion to my 4 door Quattro into a track\street car, which I have been working on for years.

Here is a pic without any engine in.


As far as I know this is the only example of this car is SA and after fixing up the suspension it handled like a dream. The 7A motor was considered as and option after the old KV 5 pot started with a blown head gasket problems.

Bought the engine from the local engine importers and had it ported and the cams ground for longer duration. Managed to get some S2 injectors from a friend and a fuel rail with locally made injector converters, from another.

Bought two sets of 48mm throttle bodies from a Toyota but then thought better of trying to have them fitted. So fitted a second Audi throttle bodies instead.


Two Simota air filters bought and fitted. Need to make a plan to separate the hot exhaust shielding from the cold air shielding so that I get the coolest air possible to the filters. So bent up some ali heat shielding to scoop cold air from under the car and duct that up to the two air cleaners. once the bumper is fitted, I will make up a proper sahpe and frame to stiffen up and enlarge the mouth of the duct


ECU is by Gotech which I fitted myself. Had a problem initially as the distributor has only one window and Gotech system needs one for each cylinder.

Had to order a new gear and have the cap machined. Dropped that in and pressed the starter button and it fired up immediately. Bit rich at first but after some fiddling with the fuel and ignition maps, now running smooth.

The engine is perfectly smooth, noise and vibration free. The loudest noise at idle is the fuel pressure regulator, until one hits the accelerator then its just induction noise. Motor revs up very fast and sounds very hungry for air.

One very happy chappy. Other mods include, A6 brakes under 15" rims and button clutch. Quad headlights, aftermarket bumper still need to be completed before car goes back on road and for a visit to the Dyno, where I hope to get about 145-150Kw.(+ 200bhp).

Will see.

[Tonks4x4]

Nice!!!! I like the twin throttle body idea, look forward to more pics...

[20Vcqdriver]

How does this work without an MAF then?
To get the most from the engine you should try and get one of the early tubular equal length 5 into 1 exhaust mainifolds as I had on mine before the 3B replaced it. properly wrapped it kept engine bay a lot cooler than before.

[Ryss]

Thanks for the comments guys.

Tonks4x4 trust you are well. Yes , the twin throttles seem to work very well. I wanted an engine that has torque and will rev freely so hopefully this will do it.

20Vcqdriver ...yes the tubular manifold is on the cards but I had to fit the engine before it can be made.

The Gotech works only on manifold pressure, RPM, airtemp, Lamda, Throttle position, engine temp. Very effective system and cost.

[20Vcqdriver]

Thanks for the comments guys.

Tonks4x4 trust you are well. Yes , the twin throttles seem to work very well. I wanted an engine that has torque and will rev freely so hopefully this will do it.

20Vcqdriver ...yes the tubular manifold is on the cards but I had to fit the engine before it can be made.

The Gotech works only on manifold pressure, RPM, airtemp, Lamda, Throttle position, engine temp. Very effective system and cost.

Ah, so making a custom one rather than use the tubular factory version. Interesting to see that, but would it not have been easier to obtain factory version as they were supposed to provide around 7bhp over the later cast version?
Looks a good project and be interested to see the dyno results with twin throttles attached. With the work you have put in and MAF restriction gone, I'd be surprised if it didn't make 210bhp+

[quattrostyle]

cool project

[WabTheKing]

I am nearing the end of a low budget conversion to my 4 door Quattro into a track\street car, which I have been working on for years.

Here is a pic without any engine in.


As far as I know this is the only example of this car is SA and after fixing up the suspension it handled like a dream. The 7A motor was considered as and option after the old KV 5 pot started with a blown head gasket problems.

Bought the engine from the local engine importers and had it ported and the cams ground for longer duration. Managed to get some S2 injectors from a friend and a fuel rail with locally made injector converters, from another.

Bought two sets of 48mm throttle bodies from a Toyota but then thought better of trying to have them fitted. So fitted a second Audi throttle bodies instead.


Two Simota air filters bought and fitted. Need to make a plan to separate the hot exhaust shielding from the cold air shielding so that I get the coolest air possible to the filters. So bent up some ali heat shielding to scoop cold air from under the car and duct that up to the two air cleaners. once the bumper is fitted, I will make up a proper sahpe and frame to stiffen up and enlarge the mouth of the duct


ECU is by Gotech which I fitted myself. Had a problem initially as the distributor has only one window and Gotech system needs one for each cylinder.

Had to order a new gear and have the cap machined. Dropped that in and pressed the starter button and it fired up immediately. Bit rich at first but after some fiddling with the fuel and ignition maps, now running smooth.

The engine is perfectly smooth, noise and vibration free. The loudest noise at idle is the fuel pressure regulator, until one hits the accelerator then its just induction noise. Motor revs up very fast and sounds very hungry for air.

One very happy chappy. Other mods include, A6 brakes under 15" rims and button clutch. Quad headlights, aftermarket bumper still need to be completed before car goes back on road and for a visit to the Dyno, where I hope to get about 145-150Kw.(+ 200bhp).

Will see.

i had the same problem with vems, so modified the cam sensor trigger wheel

[Ryss]

Ah, so making a custom one rather than use the tubular factory version. Interesting to see that, but would it not have been easier to obtain factory version as they were supposed to provide around 7bhp over the later cast version?
Looks a good project and be interested to see the dyno results with twin throttles attached. With the work you have put in and MAF restriction gone, I'd be surprised if it didn't make 210bhp+

210BHP would be nice. I was being conservative.

I was not aware that the header was available from factory. The chap I use for porting also does very good work on hand bent headers. Either way as the engine is in a different body, I would like to be sure that it fits.

WabTheKing.. with Gotech, one would need to use a different version to use a 60-2 wheel and 5 coils with no distributor, as I am using on my S2.

In the mean time I have run into a bunch of problems, mostly of my own making.

My first attempts at mapping where not correct. Had to change the configuration and start all over again. Now at least, its all starting to make sense. Would love to know how far one could advance the timing and various revs. Knock sensors are gone and replaced but my ears.

Discovered that the potentionometer (pot) (not the type u smoke) used to adjust timing(-6 degrees to O) was broken. Managed to find a replacement. Secondly a clutch problem turned out to be partly due to the battery cable (battery now in boot) that was preventing the clutch pedal from returning to its normal position.

Re-routed the battery cable which was a tough job. But clutch still does not disengage the clutch. Will try bleeding but I think I am missing 1-2mm of slave cylinder travel to release the button clutch.

Bought a new pot. While I was tinning the terminals and wires I needed a pair of pliers. Came back to the car and the pot had disappeared. After an hour of searching high and low, I found it. It fell into the space for the ashtray and rolled down below the gearlever. *&$#@**.

Now enough with the set backs!!!!. Lets hope we go forward from here. My patience is getting thin. Next weekend I planning a test drive..furiously thinking positively.

Thanks for the comments, feedback and interest. Appreciated.

[Kieron20V]

Did you use a powerbleeder to do the clutch or just pumping the pedal?

[Ryss]

Did you use a powerbleeder to do the clutch or just pumping the pedal?

I know the clutch can not be beld the normal way. Do not have a power bleeder, so may make one out of an old bottle I've got with two pipes and a bicylce pump.

But I do not think it air in the system. I think its the special pressure plate thats requires a slightly longer stroke from the slave cylinder. Clutch is also very heavy.

[Ryss]

A quick update on this project.

Clutch was removed and some machining work was required on the Flywheel so that clutch would release. Some material was removed off the flywheel, where the diaphragm bolts on, increasing clamp load and the diaphragm fingers are now flatter.Clutch was bled , and did not need a pressure bleeder.


Made a video when the car was suffering from the Vacuum leak, which upset the maps a little, but still gives one idea of the induction sound I am talking about. Hope your speakers are better than mine. http://www.youtube.com/watch?v=lLA5POICc3Q

Discovered the ARB was touching the sump. Decided to use one off an A4 as it is a much better fit than the original which would have to be fitted upside down to clear the sump of the engine. Worked out how the make and adapt the necessary mountings onto the subframe and the control arms.



On the control arms used the ARB mountings from a Golf with an insert to match the dia of the bolt and the rubber bush and drilled a larger hole in the A4 ARB to match. Not such an easy job on the subframe mountings. As a temporary measure I have just used a split piece of rubber pipe in place of the standard bush for the ARB, which is too big for the original fitting. Will be much better as the new ARB is both much lighter and suspect, also stiffer than the original. (larger dia and hollow construction). Very pleased with the result. Had a panic when I thought "On full lock, will the wheel clear the ARB as its a lot wider on the corners" Checked and there is plenty space between wheel and ARB. This modification will work on the S2 as well, if the S2 has pressed steel control arms.

Took the car for a drive so I could do a full acceleration test of about 0.5KM. Umm first, the test run. Roads were wet and got some wheel spin just on acceleration, without even trying, but as stated road was wet. On the way back, 1 st over very fast, 2nd induction noise is noticeable but as the revs climb, so this turns into a howl that sounds like an intake to a jet engine. Never heard anything like it... except maybe a Mazda rotary in full cry. Pretty quick, but I think, still plenty of room for improvement, when the map is refined. Kept my eyes on the road, so can not even say what the rev change point was.

However, as a result of the test, what I thought was a clutch judder, at very low RPM in 1st and reverse, has turned out to be something else, of a more permanent nature. I suspect it is the center bearing on the prop shaft that has collapsed, as while I'm driving, it feels like the universal joint is jumping around under the car, causing the vibration, under any load condition. So need to whip that out and take it in for fixing. .

ARB front suspension sounds solid. No funny noises.. going over speed bumps etc., so thats good news.

I suppose I will still have plenty of these shake down problems.

[Tonks4x4]

Stick with it... It all looks promising

I love outback engineering sometimes it creates great monsters...

[mcandmar]

Very interesting project, highly recommend you find a 5-1 manifold off an early car as it transforms the character of the engine, especially top end.

Also noticed you have what looks like an alternator on the exhaust side of the engine, did you move it there as i have never seen that before?

[Ryss]

Very interesting project, highly recommend you find a 5-1 manifold off an early car as it transforms the character of the engine, especially top end.

Also noticed you have what looks like an alternator on the exhaust side of the engine, did you move it there as i have never seen that before?

Yep .. I moved the alternator so that it does not sit inside the radiator ducting and to shorten the wiring. Brackets off an old 5 pot Passat. Very observant of you to note that. On the ball.

With regard to the 5 into 1. Has been been discussed in this thread. I am in South Africa. The 7A cars were never sold in this country so its not easy to find a manifold. Will have one made if I find the power drops off at high RPM, which I have limited to 7200rpm.

[mcandmar]

I noticed the nice alloy snub mount bracket/alt mount that all looked factory. Passat eh, good to know

Show this pic to your exhaust guy, will make his head explode . They do come up for sale from time to time but would probably cost as much to ship one to you.