Audi A4 with a V8 4.2 swap

[fury583867]

Hey guys I had my b7 a4 for 3 months now and looking for more power. I thought about doing a full build on the 2.0t. plan B. is to do a 4.2 engine swap. what find between plan a and plan b is with plan A is limitless with building. still expensive but risk with breakage. Plan B is rght of the back 300+hp and extremely expansive to upgrade such as supercharging etc. I need some feed back....your thoughts

[eyesolution]

Buy an rs4

[jeffrey146]

Personally I wouldn't. Buy something that already has that motor in it or something. As usual you would need to do at least the motor/trans/ecu. You would be looking at at least 6k minimum without any labor. Personally I love the 4.2 there isn't a late year audi motor I would swap it with. Also, be aware of the timing chain issues that motor can have. Sure, it certainly isnt as big of an issue as people want to pretend it is. However, I would probably buy a higher millage motor and do all that stuff on it. I still would just buy an S4 or RS. Think about all the other things an S4 has that you want. I mean, the seats? A4 seats just kind of suck.

[LINDW4LL]

If you want to swap, drop a 2.7T into your B7. Pretty straightforward swap and more power than the 4.2. If you want the 4.2, just buy an S4.

[A4Quattro > all]

If you want to swap, drop a 2.7T into your B7. Pretty straightforward swap and more power than the 4.2. If you want the 4.2, just buy an S4.

+1

[basemntboy]

+1

+2 If you're set on swapping a 2.7 would be the coolest and easiest to modify. I don't know that a whole lot of people would be interested in a 4.2 b7 a4. A 2.7t b7 will have half this forum punching each others dicks to be the first in line haha. Like was already mentioned there are many other features gained than just the motor by going the S4 route. Also re-saleability would be much much better.

[jsandor91]

go k0r k04 or frankenturbo... much less then a engine swap and 300+ crank horsepower with a 2.0t

or buy a different car.

[mec]

Right off the bat. That is the expressing you are looking for.

Want a v8, sell the car get an s4/rs4. The amount of money you spend in combination with the amount of time will far outweigh the benefits. Not to mention selling the car will be tough.

Also the 2.0t has way more options for upgrades than the 4.2. Many more options

[fury583867]

Good points guys..... I hear that a lot about going 2.7. if I decided to do a 2.7 will I need to change my tranny? My 2.0t is a 6 speed. I get it about needing the ecu but what about my b7 cluster. will I have to use a standalone for this swap?

[LINDW4LL]

Good points guys..... I hear that a lot about going 2.7. if I decided to do a 2.7 will I need to change my tranny? My 2.0t is a 6 speed. I get it about needing the ecu but what about my b7 cluster. will I have to use a standalone for this swap?

B5 S4 ECUs don't have immobilizers. So I don't think the cluster would be an issue. And you can use your transmission I believe.

[ericpaulyoung]

No way, the 4.2 swap is super easy. The best part is since your b7 a4 ECU is already tuned to run boost, you can build the 4.2 for turbocharging no problem. Something everybody forgets to mention is that the 4.2 is an 8 cylinder, and your ECU is setup for 4 cylinders. At first you are like "so what", but then you realize that because of the firing order you can just split the coil leads for cylinders 1, 2, 3, 4 of you four banger and feed cylinders [1,5] [2,6] [3,7] [4,8]! You don't even have to change the harness, just put a Y in each of the capacitor wires.

If you look around a bit and are patient you can get a 4.2 out of a wrecked car for around $2k, so figure in selling your OEM 2.0FSI for at least $1500, and you will be at only $500 plus the build parts for making the 4.2 a turbocharged engine.
- Eric

[LINDW4LL]

But 4.2s blow up under boost!! 034s STK would be tits on a 4.2 though.

[ericpaulyoung]

But 4.2s blow up under boost!! 034s STK would be tits on a 4.2 though.

True. OP, you should at least count on new connecting rods and a new set of rings in this build.
- Eric

[AudiA4_20T]

No way, the 4.2 swap is super easy. The best part is since your b7 a4 ECU is already tuned to run boost, you can build the 4.2 for turbocharging no problem. Something everybody forgets to mention is that the 4.2 is an 8 cylinder, and your ECU is setup for 4 cylinders. At first you are like "so what", but then you realize that because of the firing order you can just split the coil leads for cylinders 1, 2, 3, 4 of you four banger and feed cylinders [1,5] [2,6] [3,7] [4,8]! You don't even have to change the harness, just put a Y in each of the capacitor wires.

If you look around a bit and are patient you can get a 4.2 out of a wrecked car for around $2k, so figure in selling your OEM 2.0FSI for at least $1500, and you will be at only $500 plus the build parts for making the 4.2 a turbocharged engine.
- Eric

WHAT? Are you just trying to troll with this post?

[ericpaulyoung]

Clint, you need to take a college course on humor.

Of course I am totally serious, but you have to remember to use high quality copper Y connectors.

Eric

[AudiA4_20T]

Clint, you need to take a college course on humor.

Of course I am totally serious, but you have to remember to use high quality copper Y connectors.

Eric

you bastid!

[ericpaulyoung]

Or something with a high Tin content if you have good insulation on the wires. Tin won't help if the wires are older and the sheath is starting to crack :/