Pictures: S8 intake manifold vs regular intake manifold

[dpod]

Audiziners have really helped me alot over the past few years and its time I give back to the community. I personally have the 2.7t but my dad got him self a 4.2 and recently i talked him into getting a intake manifold of an S8. Exterior wise they look pretty much the same, but its the inside that counts right? I took some pics nad hopefully they will give all the 4.2 guys a better idea of the S8 manifold.

A regular intake manifold that came on the a6 and the a8






And the S8 intake manifold.








Conclusion: It's pretty obvious that the S8 manifold is more smooth and more "direct" to each cylinder. Some other physical difference is that the S8 manifold id a bit lighter, the flaps open up much easier, and they are made out of rubber. the regular manifold is a bit heaver, require more force to open the flaps, and it inst as smooth, i'll update you guys in a couple of days about the performance difference.

[beemercer]

nice pictures, is his car still on a stock tune?

[Brandon@Roc-Euro]

Im interested in performance difference

[v8a6]

On the stock engine, I dont think there will be any performance difference. At 300 hp, I dont think the stock manifold is a bottleneck. Plus, you will have to update your ECU to get it to adjust for dual variable intake runners, since the stock is triple. Otherwise, you will have weird surges at different times.

[dpod]

nice pictures, is his car still on a stock tune?

For now yes, i'll see how things go, but v8a6 has a good point, i'll let you guys know how things go.

[dpod]

Im interested in performance difference

Going on a test drive in about an hour, will post results, no dynos of coarse but i'll try to describe it best as I can.

[dpod]

On the stock engine, I dont think there will be any performance difference. At 300 hp, I dont think the stock manifold is a bottleneck. Plus, you will have to update your ECU to get it to adjust for dual variable intake runners, since the stock is triple. Otherwise, you will have weird surges at different times.

As i mentioned before, going on a test drive soon, so far it starts up perfect and everything thing seems fine.

[beemercer]

For now yes, i'll see how things go, but v8a6 has a good point, i'll let you guys know how things go.

yeah thats where I was going with my question, I'd be concerned about the flaps triggering wrong. Ask rednecktruck what he did with his A6 manifold on an S6 tune, that should give you some insight of potential issues. And take care resealing the two halves.

[dpod]

Well heres the performance conlcultion

- Alot more low end torque, reminded me of an S6
- The car feels lighter
- Faster acceleration
- the transmission feels light
- Basically the car feels lighter and much faster
- So far no weird surges as v8a6 mentioned

[khalimadeath]

Butt dyno ftw

[v8a6]

Butt dyno ftw

LOL

[Widebody4.2]

LOL

Consign that

[dpod]

Butt dyno ftw

LOL its one of the most accurate!

[chapterfour08]

where can i get an s8 intake manifold?

[v8a6]

auto wreckers

BTW, the S8 manifold is the same as the S6 one, so either will do.

[Scotty@Advanced]

I have an S6 manifold on my A6 for about 6 years (50,000 miles) and it's tits for top end but low end is a dog compared to the A6 manifold that was on there, I'm not sure if the A6 ecm is opening plates at the proper rpms as the S6 ecu would. It will also surge inconsistently at times.

[Audimuscle]

I have an S6 manifold on my A6 for about 6 years (50,000 miles) and it's tits for top end but low end is a dog compared to the A6 manifold that was on there, I'm not sure if the A6 ecm is opening plates at the proper rpms as the S6 ecu would. It will also surge inconsistently at times.

Scotty is that with an S6 file? I have JHM tune and still with stock mani and I notice the low end dogness untill 3k RPM. Just wondering if yours has the S6 file running with that S6 mani

[Scotty@Advanced]

Scotty is that with an S6 file? I have JHM tune and still with stock mani and I notice the low end dogness untill 3k RPM. Just wondering if yours has the S6 file running with that S6 mani

I had an A6 ECM for the first few years then switched over to an S6 TCM and ECM fuel injectors and MAF. bottom end lag seemed unchanged, but top end improved. I'm using the higher geared A6 trans so maybe that has something to do with it.

[alterdcreations]

Question, were these v8 manifolds designed so that they can be reversed? meaning pointing the throttle body to the front of the engine bay?

[Scotty@Advanced]

Question, were these v8 manifolds designed so that they can be reversed? meaning pointing the throttle body to the front of the engine bay?

It's possible but due to the breather plate in the valley pan, you either have to space the manifold up by an inch or modify the valley pan cover.

[alterdcreations]

cool

[Vinnie981]

this info is wrong......

the a8 d3 4.2l intake is not the same as the a6 c5 4.2l

[Scotty@Advanced]

this info is wrong......

the a8 d3 4.2l intake is not the same as the a6 c5 4.2l

I could have told you that.

[VikingoTropical]

If I make an race engine with no flaps I suppose we have some hp win?

[IMG][/IMG]
My car

[Vinnie981]

No. Unless your going under forced induction keep the flaps. Otherwise you will loose HP

[Scotty@Advanced]

If I make an race engine with no flaps I suppose we have some hp win?

[IMG][/IMG]
My car

Not really the 4.2's broad torque curve is a product of the variable intake.

[pee quu]

when putting the two half back together is any sealant needed or just bolt them back together?

[Korben007]

Yes sealant

Rory - Audi Customization Specialist

[pee quu]

this info is wrong......

the a8 d3 4.2l intake is not the same as the a6 c5 4.2l

d3 4.2 intake is the same as a c5 s6

[pee quu]

Yes sealant

Rory - Audi Customization Specialist

you would just put it over the rubber seal that's already there?

[M3lvo]

Does the 299 hp throttlebody still fit the s6/s8 intake manifold? or does it need the s throttlebody too?
Curious, because if the intake and exhaust really bump up the power from 299 to 340 ish that would mean I can get jus a regular a6 instead of an s6 for the swap! much cheaper.
It does need an s6 instead of a6 file after that swap I guess?
Also I keep reading that the s6 and s8 engine's have different cams. from what I read someone claims this : s6 more aggressive intake cams only, and s8 more aggressive intake and exhaust cams.
Makes me wonder where the AQH's 360 hp comes from.
Just looking for a 330hp + 4.2 setup for a b5 a4.

sorry for bringing this back from the dead...

[Bordom]

Does the 299 hp throttlebody still fit the s6/s8 intake manifold? or does it need the s throttlebody too?
Curious, because if the intake and exhaust really bump up the power from 299 to 340 ish that would mean I can get jus a regular a6 instead of an s6 for the swap! much cheaper.
It does need an s6 instead of a6 file after that swap I guess?
Also I keep reading that the s6 and s8 engine's have different cams. from what I read someone claims this : s6 more aggressive intake cams only, and s8 more aggressive intake and exhaust cams.
Makes me wonder where the AQH's 360 hp comes from.
Just looking for a 330hp + 4.2 setup for a b5 a4.

sorry for bringing this back from the dead...

If you want 340hp that the S6 provides, you can't just swap intake and exhaust and magically have an extra 40hp on this motor.

Differences between the S6 to the A6:
Camshafts
Intake Manifold
Throttle Body Size (2000 A6 has smaller TB than S6, but 2001-04 A6 have same TB as S6)
ECU Tuning
Exhaust Manifold (unless its a 2000 A6 as they have the S6/S8 Manifolds)
Connecting Rods

To make that horsepower up, you'll need Intake, ECU tune, intake cams and exhaust manifold. (Don't need Throttle body unless 00 A6)

S8 has more aggressive engine tuning and exhaust cams for that extra 20hp.

[M3lvo]

If you want 340hp that the S6 provides, you can't just swap intake and exhaust and magically have an extra 40hp on this motor.

Differences between the S6 to the A6:
Camshafts
Intake Manifold
Throttle Body Size (2000 A6 has smaller TB than S6, but 2001-04 A6 have same TB as S6)
ECU Tuning
Exhaust Manifold (unless its a 2000 A6 as they have the S6/S8 Manifolds)
Connecting Rods

To make that horsepower up, you'll need Intake, ECU tune, intake cams and exhaust manifold. (Don't need Throttle body unless 00 A6)

S8 has more aggressive engine tuning and exhaust cams for that extra 20hp.

I know I did not expect magic power from just the intake and exhaust.

Thats exactly why I asked what would bring me close to that.
All those differences I also found while researching, good that someone can confirm it.

So with an s6 intake manifold/throttlebody and an s6 file on the ecu and a larger 2.5 inch dual exhaust I should be able to make a bit more power?
Hoping/aiming for 330ish without doing the cams .
That should still be worth it I guess. +- 14 hp difference, but a ''basic'' a6 4.2 is so much cheaper to get as a donor vehicle.

would a stock 2.4 30v 5spd gearbox/drivetrain hold that kind of power? because most a6's I see are auto. rather keep it manual.

[Bordom]

I know I did not expect magic power from just the intake and exhaust.

Thats exactly why I asked what would bring me close to that.
All those differences I also found while researching, good that someone can confirm it.

So with an s6 intake manifold/throttlebody and an s6 file on the ecu and a larger 2.5 inch dual exhaust I should be able to make a bit more power?
Hoping/aiming for 330ish without doing the cams .
That should still be worth it I guess. +- 14 hp difference, but a ''basic'' a6 4.2 is so much cheaper to get as a donor vehicle.

would a stock 2.4 30v 5spd gearbox/drivetrain hold that kind of power? because most a6's I see are auto. rather keep it manual.

That really depends. The A6/S6/S8 injectors are also slightly different for each. But it's almost negligible. I'd have to look it up again but the A6 injectors are about 200cc and the S6/S8 are around 205-215cc.

Intake would be the most noticeable gain paired with the S6 tune.

As for 5spd drivetrain, people have been dumping 400+whp/wtq through those transmissions without issue. You shouldn't have problems especially since its NA. Bare minimum is a stock 2.7 clutch but I recommend going with a B7 RS4 clutch and associated flywheel.

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[M3lvo]

That really depends. The A6/S6/S8 injectors are also slightly different for each. But it's almost negligible. I'd have to look it up again but the A6 injectors are about 200cc and the S6/S8 are around 205-215cc.

Intake would be the most noticeable gain paired with the S6 tune.

As for 5spd drivetrain, people have been dumping 400+whp/wtq through those transmissions without issue. You shouldn't have problems especially since its NA. Bare minimum is a stock 2.7 clutch but I recommend going with a B7 RS4 clutch and associated flywheel.

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I see, so thats good news!, since I'm not looking for exactly s6 power. just a bit more then the 299 they come with stock.
So injectors probably also not worth it to swap over.
I think the plan is to just look for a s6 intake s6 file with all the stuff like immo and sai egr etc. coded out, and a upgraded exhaust maybe even custom but thats for later.

Oh boy 400 I won't exceed so I should be good there.
Any reason for the b7 rs4 clutch? is that a straight bolt in kind off deal? or do I need spacers etc. for it.

[Mad Cow]

S6 and S8 also have a higher compression ratio, that and the cams is where most of the extra power comes from. You can't just swap external parts over and flash an S6 tune and expect an extra x horsepower. First off, the S6 tune won't even work because the MAF and injectors are different, never mind the fact that it's tuned for different cams and compression. It'll barely run best case scenario. Second, swapping over the intake manifold will just end with you losing torque and no extra bump in power, because again the cams are still the same and can't flow enough in higher rpms to take advantage of the manifold design. Exhaust manifolds can't hurt, but the difference would probably be pretty minimal. I swapped my exhaust manifolds over to the S6 style, but only because the originals were in bad shape and I got a great deal on S6 downpipes with high flow cats. Which leads me to my next point, the downpipes are different and they have to match the manifolds as well. The rest of the stock exhaust is already very good, it's mandrel bent and made of relatively thick stainless steel. You won't gain anything from bigger tubing and in fact might lose power, and unless you pay big bucks for a custom mandrel bent stainless system it'll actually be worse than stock.

There's a lot of variables here, and unless you account for all of them you'll end up with something that's worse than stock, maybe minimal improvement at best.

The 5spd will handle the power but it's probably not a long term solution, especially if you drive hard. Since you mention the 2.4 I assume you can get a TDI 6spd locally, that would be the ideal option because it's more than strong enough and the gear ratios will be better suited to the motor.

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[M3lvo]

Well apperntly a ART/AWN motor has the same compression as an s6. : https://www.audizine.com/forum/showt...L-V8-A6-S6-RS6
Cams do something also sure. But like mentioned above I'm looking for a bump in power not an exact copy of an s6 engine.
Also a S series intake manifold does do some good instead of making it worse, this is also mentioned above.
I've read around on the forum's here and found quite a few people running s6 files. These are apparently modified s6 files, I think modified to work with an a6 engine.
The exhaust is like I said something I'm going to worry about later. Maybe try to use stock as much as possible as they are the same size for the s6 anyway.

So I think ending up with worse might be a bit exaggerated.

I indeed found a multiple tdi 01e 6 speeds in my area. some 1.9 some 2.5 tdi.

[Bordom]

Lot's of people have run the S6 file on a totally stock A6 4.2. You only get reduced power unless you add the big hardware S6 items in (Intake, Intake cams, Injectors). The S6 tune is a real dog with the A6 3 stage intake. Swapping to a 2 Stage intake from an S6/S8 or D3 A8 with vastly improve driveability. I was lucky enough to get an S6 engine for my swap, so everything worked for me.

If you get a B7 clutch, you need to have the appropriate flywheel. What I mean by that is, the flywheel is machined differently to accept the B7 unit, which holds more power than a B5 RS4 clutch. It also has the Metal SAC springs so that also helps with durabilty.

I recommend getting a TDI 01E since they're plentiful around you and the mileage gain would be better than a 5spd.

[Mad Cow]

Huh, you're right about compression, I thought the S motors were 11.5 to 1 for some reason. My point with the cams and intake manifold still stands, the A6 manifold is designed for mid-range torque rather than top end power like the S manifolds. So swapping an S manifold into an otherwise stock A6 will leave you with less mid-range torque and you won't get the full top end benefit because of the stock cams. You have to keep in mind these motors are already tuned very well from the factory, the appropriate tradeoffs have been made and there's very little you can do that will result in a net gain. You'll lose more than you gain unless you're tuning for a specific use case. Ask anybody who tunes VAG motors professionally and you'll get the same response, it's not worth the time, money, and potential headache for the average person. The most you can hope to do is advance ignition timing a bit, but that comes with its own tradeoffs and can be done regardless of which tune you run.

I've personally modified an S6 tune to work with my car, and let me tell you there's no way it'll run properly without at least accounting for the injectors and MAF. It might get you by short term, but I can tell you definitively that my motor barely ran with a stock S6 tune. Sure it more or less idled but I wouldn't have driven it in that state unless I had no other choice. Once I really dove into it I found so many small differences, and I'm still chasing little issues to this day. Things like an unnatural bump or drop in power over a specific rpm range under certain conditions, things you won't notice until you daily drive it for a while. So far I've copied over a couple dozen maps from the original A6 file and it's still not perfect. I've ran files that people have personally vouched for and claimed were perfect, they were far from it, which led me to creating a tune myself.

On that note though, I really need to share my work up to this point already because there's very little documentation around this subject, just tons of anecdotes and conjecture.

Sorry for the wall of text, and I don't mean to discourage, I just want to get the point across that you can't just mix and match hardware and software from 2 different motors and expect it all to work perfectly from the beginning.

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[M3lvo]

Lot's of people have run the S6 file on a totally stock A6 4.2. You only get reduced power unless you add the big hardware S6 items in (Intake, Intake cams, Injectors). The S6 tune is a real dog with the A6 3 stage intake. Swapping to a 2 Stage intake from an S6/S8 or D3 A8 with vastly improve driveability. I was lucky enough to get an S6 engine for my swap, so everything worked for me.

If you get a B7 clutch, you need to have the appropriate flywheel. What I mean by that is, the flywheel is machined differently to accept the B7 unit, which holds more power than a B5 RS4 clutch. It also has the Metal SAC springs so that also helps with durabilty.

I recommend getting a TDI 01E since they're plentiful around you and the mileage gain would be better than a 5spd.

Thats the plan, to get most of the s6 hardware where possible, maybe even find a full s6 engine. A complete s6 donor will be a bit pricey I think.

So the b7 is mostly for a more reliable clutch setup, I don't think I'm going to get past 310 tq so if it holds that I'm fine.

the 01e also needs anoter rear diff correct? to match the final drive?
Just want to have a nice short box preferably, for the 0-60's etc. thats my kind of driving, not really a vmax type of driver. just fast 0-60's is what I like.
Also don't think its gonna be a highway driver that much, as it'l be my project car.