masao

I bought a 91 parts car that had an awesome engine and a custom exaust for it, but it has been sitting for like 3-4 months, and the battery is dead, If I can get it running, I want to drop it into my 86 n/a.

The engine in my parts car has 130 grand, with 30 - 40 grand since rebuil w/ new apex seals, but its been sitting for like 3-4 months. If I can get it running, I want to drop it in my S4. My 86 S4 has an 87 S4 engine in it right now with about 140 grand on the original apex seals, and it runs pretty good. But about 6 months ago, it got STP fuel injector cleaner run through it. I ran it almost out of gas with the 3 tanks after that happened, but the car hasn't been the same, I am a little short on power and I getting about 15 to 20 mpg. I want to drop in this S5 and then rebuild the S4 for some serious power.

I want to know how simple it is to drop an S5 into an S4 car. I still have the S5 alternator, the S5 computer, and the exaust, that I know I need.What kind of fun can I expect with this swap?

I am looking forward to an extra 15 base hp.

J-Rat

iTrader: (2)

Well, you probably wont find it by putting that S5 motor into that S4 car. Sorry to say. Some of that HP was afforded by the increase in compression, and more of it was found by the VDI and the 6-ports. Both of which are ECU controlled by the S5 computer.

So just put the S5 computer in the S4 car you say? I wont say you cant do it, but the amount of work you are looking at would boggle your mind.

Your best bet, IMHO, is to strip that S5 motor down to the block, then run some S4 intakes. But then again, this runs into some problems because the S5 motor is a non-EGR motor, so the S4 intake leaves a gap for exhaust to escape from the intermediate housing.

Can you use an S5 lower and an S4 upper? Dont really know on that one.

Rat

BlaCkPlaGUE

If I were you, I'd take off the AC and power steering to make the install easier.

You'll have to remove the exhaust and heat shields to get at the driveshaft bolts and tranny mounts. Remove your shifter, take off the hood, remove the radiator and all hoses. Mark everything for re-install and disconnect the harness on the left side of the engine and pull it out of the firewall after disconnecting it from the ecu.

Your pretty much looking at the typical engine swap, the hardest things about it are probably removing the exhaust, and then just remembering where all connectors/wires go. Theres probably alot more to it than I have told you so far, but its just to give you an idea.

masao

Yeah I know its going to be a pain to swap engines, but I am under the impression that it isnt much more work than the average engine swap. Let me know if I am wrong.

In doing research I have found multiple sources that say the S4 n/a makes 146 whp and the S5 n/a makes 160 whp. PLus the fact that my S5 engine has fairly new apex seals and fewer miles than my S4 engine, so I still think I want to do this swap.

Has anyone atempted this swap or heard it done sucessfully?

J-Rat

iTrader: (2)

Oh, I have done it, and I just told you how you will run into some difficulty.

Here is Kevins take on it.

http://www.rotaryresurrection.com/ro...ries4swap.html

uRizen

iTrader: (2)

Make sure you use the S5 intake if you can. It's better flowing and the VDI helps out. I'm getting the parts ready to do the S5 intake swap on my S4 motor and it's not too bad getting everything to work. From what I've read you can use the exhuast backpressure to open teh VDI as well if you have the Racing Beat presilencer (it has more PSI coming off the split-air pipe and teh VDi requires ~5psi, the aux. ports need ~3psi.) You can also open the VDI and aux. ports with an electric airpump and controller.

Isn't there also a small difference in the rear plate for the tranny bolt holes? I thought it was slightly different and you needed an adaptor plate or S4 rear iron.

J-Rat

iTrader: (2)

No difference that I am aware of.

masao

Should I use the S5 tranny since its still functional and has been on that engine?
(and its super smooth from what the previos owner told me)

Kingofl337

I did the swap into an S5 with an S4 intake. It was very easy basicly drop in except the front cover because I kept the OMP. You premix it is drop in.

Adam