JHM C5 A6/S6 4.2 Development

[Dan@JHM]

As some of you may know of our involvement with the b6/b7 s4 and the products we have developed and will continue to develop even more, you may not have known we got our 4.2 start from the c5 platform.




Its time to show you some of the products we are working and services we offer for the C5 as well.


This is just the start:


First off yes we do have an ECU(engine) and TCU(transmission) tune for the C5 4.2. The engine tuning will be very similar to our b6/b7 s4 tunes, we optimize the tune to give you as much performance as possible while leaving all the safety features in to be as safe as possible.



Pricing:

Ecu = $500 plus shipping

Tcu = $500 plus shipping

Combo = $900 plus shipping

*Note* you must send your ecu and tcu in to be programmed, turn around time is same day if not next day at the latest.


The downpipes we currently are running on our 4.2 are "piggie pipes". They are basically modified stock downpipes where we remove the pre-cat and relocate the secondary o2 sensor so you will not get a catalyst efficiency code. We currently do not have a set of C5 4.2 downpipes in-stock at the moment but can modify any ones that sends them in. If we get enough interest we can make full 2.5" downpipes for this platform but is up to you guys really.




The cat-back we are running is a custom setup using a high flowing x-pipe design. As with the downpipes, if we get enough interest from you guys we will work with FI to make a full cat back system just like the b6/b7 s4:




Some other notable products we currently offer for the C5 4.2:


JHM C5 A6/S6 4.2L (40v) Lightweight Crank Pulley:

http://www.jhmotorsports.com/shop/ca...roducts_id=366




JHM 4.2L (40v) intake spacers - 10mm thick:

http://www.jhmotorsports.com/shop/ca...roducts_id=295




Motor Mounts (Pair) - Stern Pro w resistors for the 4.2L:

http://www.jhmotorsports.com/shop/ca...roducts_id=600




Apikol rear diff mount for the C5:




JHM/034 Transmission mounts with adapters and hardware:




As stated before this is just the beginning, stay tuned for more video and information about the following:

- 01E 6 Speed conversion
- S8 Intake Manifold Swap
- S8 Cam Swap
- Brakes Options
- 13 second video/timeslips
- 12 second video/timeslips
- Nitrous
- Forced Induction????

[G Men 08]

should be fun

what kind of numbers would one expect from the chip and dps?

[Dan@JHM]

should be fun

what kind of numbers would one expect from the chip and dps?

Well with only a tune, piggies and cat back we got the car to run a 14.0@100 mph in the 1/4. That may not seem like much but is over a second faster then they run stock.

[G Men 08]

yeah thats not bad for a 4000 pound car. Does that include the tans ecu tune as well?

[Dan@JHM]

yeah thats not bad for a 4000 pound car. Does that include the tans ecu tune as well?

Yes TCU tune as well.


What happened to those downpipes posted earlier? I was going to say those are DEFINITELY modified downpipes. Federal emissions require the use of pre-cats for start up.

[SteveKen]

Dan. I deleted my post and PM'd you instead.

My NA 4.2 S6 does not have pre-cats.

ETKA drawings verify this and a quick glance at the C5 3.0 and 2.7T show the precats on the downpipe drawings.

[Scotty@Advanced]

Dan. I deleted my post and PM'd you instead.

My NA 4.2 S6 does not have pre-cats.

ETKA drawings verify this and a quick glance at the C5 3.0 and 2.7T show the precats on the downpipe drawings.

The 01-04 4.2's in the A6 have the pre cats, the 02-03 S6, and the 00 A6 4.2 with the ART have no pre cats, and use a slightly larger downpipe diameter and exhaust manifold outlets.

[Gumby]

So Dan,

is that your c5 with the Apikol rear diff mount? How much does it change the feel of the car? Launch harder?

[SteveKen]

The 01-04 4.2's in the A6 have the pre cats, the 02-03 S6, and the 00 A6 4.2 with the ART have no pre cats, and use a slightly larger downpipe diameter and exhaust manifold outlets.

Ah, that explains it. I'd say that it would be desirable to upgrade to the S6 manifolds an downpipes, then.

Here's an interesting shot of the manifold outlet.

[V8weight]

Are you able to custom tune the TCU? I have an RS6 with a tune and an MTM tcu. With my tune, I'm exceeding the specified torque limits in the MTM tcu in the lower rpm range, causing a torque reduction request by the tcu (engine intervention).

[Dan@JHM]

The etka pic for the 2001 4.2 a6 shows they have no pre cats as well but they do. I would be curious to hear from another S6 owner about their pre cats as well. If they are like the European version they are already a leg up.

So Dan,

is that your c5 with the Apikol rear diff mount? How much does it change the feel of the car? Launch harder?

Yes that is my c5 a6 with the apikol rear diff mount. When I did the 6 speed swap on my car I left all the stock mounts in and the drive train was an absolute slop nightmare. The first things I changed was the tranny mounts which helped out a lot, then changed out the rear diff mount. As soon as I removed my rear diff mount I found it to be cracked pretty bad:



So yes the apikol diff mount got rid of the infamous "clunk" sound and helped clean up the drive train slop a lot as well.

Are you able to custom tune the TCU? I have an RS6 with a tune and an MTM tcu. With my tune, I'm exceeding the specified torque limits in the MTM tcu in the lower rpm range, causing a torque reduction request by the tcu (engine intervention).

Please send an email to [email protected] and we will see what we can do.

[beemercer]

Ah, that explains it. I'd say that it would be desirable to upgrade to the S6 manifolds an downpipes, then.

Here's an interesting shot of the manifold outlet.

Looks just like the B6/B7 S4 exhaust manifolds. Time to slap some headers on one of these bitches. What's the final drive on these cars, the Auto B6 S4's do very well with the JHM headers because they spend so much more time in gear (Justincredible's car).

Anyways good to see more development for the 4.2's.

[Justincredible]

Looks just like the B6/B7 S4 exhaust manifolds. Time to slap some headers on one of these bitches. What's the final drive on these cars, the Auto B6 S4's do very well with the JHM headers because they spend so much more time in gear (Justincredible's car).

Anyways good to see more development for the 4.2's.

Yes very well. How funny I come here in this section from time to time as I started with a A6.

I know JHM took over the V8 program from TCU to ECU's but this is what I had back in the day
http://www.streetfire.net/video/vast...ile_152645.htm

The TCU was very noticeable and well worth the money. Even the ECU was very much worth the money

[G Men 08]

Well then that car sounded sick!! what exhaust setup did you have? and is there a way for them to tune the shift point? I wouldn't want my car to shift at 7200 and hit the rev limiter when I pass someone (piece of mind) I think 6600 would be perfect.

[V8weight]

Yes very well. How funny I come here in this section from time to time as I started with a A6.

I know JHM took over the V8 program from TCU to ECU's but this is what I had back in the day
http://www.streetfire.net/video/vast...ile_152645.htm

The TCU was very noticeable and well worth the money. Even the ECU was very much worth the money

If you care to remember Justin, I started out with a B6 S4, and continued to check into the S4 forums, until you called me a troll and told me to leave. I'm here to extend you the same courtesy. :)

[Scotty@Advanced]

The etka pic for the 2001 4.2 a6 shows they have no pre cats as well but they do. I would be curious to hear from another S6 owner about their pre cats as well. If they are like the European version they are already a leg up.

The ETKA image doesn't mean much, I've got every 4.2 C5 engine variant on a shelf and can verify that for you.

[monkeytronic]

What's the final drive on these cars, the Auto B6 S4's do very well with the JHM headers because they spend so much more time in gear (Justincredible's car).

Factory spec C5 A6/S6 4.2s should both have the same 2.73:1 final drive ratio while AFAIK B6/B7 S4s with automatics would have a shorter 3.54:1 ratio instead.

[ChescoS6]

Price for a C5 S6 FI catback please.. I guess it would have to be custom ...maybe a bit longer than a B6 S4 exhaust. I'm ready to drive to Jersey and get one from Autospeed / ASP but would like to have options.

[Hambone101]

Is there an estimate amount for the custom dp's and exhaust? I'm running into a catalyst efficiency code and would like a way around that and wake up the car a bit.

[brewmastr]

wow great stuff, keep it up!

[jaycurn]

This is exciting stuff and it's fabulous to see some progress for these cars! I'd defo be interested in the catback as well and possibly the downpipe application. However, for an S6 with no precats, do you think the custom downpipe idea is worth the money and that we'd really see any measurable gains?

[G Men 08]

Yeah, I would love to put the DPS on my car, But idk about the price. How much to send in my stock ones and have you guys work your magic?

[beemercer]

Yeah, I would love to put the DPS on my car, But idk about the price. How much to send in my stock ones and have you guys work your magic?

http://www.jhmotorsports.com/shop/ca...roducts_id=395

It runs $450 for the S4 downpipes. If you have pre-cats on yours it normally is a big difference maker, great bang for the buck.

[A4edwin]

what about the nos kit for the c5?

[pit viper]

Saw the manifold setup for it in another thread. Really nice.

[TheBlueMartin]

I have my C5 4.2 for 5 years, and there isnt squat offered for it. NOW this comes out....

[A4edwin]

I saw it on the web site does it fit the c5 4.2? The 4.2 has become more affordable so there's more interest on getting more power. Have you noticed in the past year how many more people there are with 4.2's on here? It been pretty much dominated by the 2.7.

[G Men 08]

I have my C5 4.2 for 5 years, and there isnt squat offered for it. NOW this comes out....

Welp, in that case its time to buy a new one as a toy!!

[Machupo]

count another C5 S6 in for DPs if you decide to make them (probably do the whole exhaust/tune bit too)

[khalimadeath]

what about this forced induction you speak of sir? lol

[EinSchnellAudi]

Man, if my 4.2 didn't have the few issues that it does have, I would be all over this. Who knows, we'll see how things play out. Looking good so far.

[A4edwin]

wish you guys did this earlier before i spent 1500 on the milltek exhaust! what exactly will dp's do for my car?

[Dan@JHM]

what about the nos kit for the c5?

The nitrous kit we developed for the b6/b7 s4 4.2 is a direct bolt onto the 4.2 a6/s6 as well.

Yeah, I would love to put the DPS on my car, But idk about the price. How much to send in my stock ones and have you guys work your magic?

We can modify your downpipes(remove precats, relocate o2 sensors) for $400.0

This is exciting stuff and it's fabulous to see some progress for these cars! I'd defo be interested in the catback as well and possibly the downpipe application. However, for an S6 with no precats, do you think the custom downpipe idea is worth the money and that we'd really see any measurable gains?

It does give you a leg up to start with pre-catless downpipes. The one negative thing about the stock downpipes is they taper down to about 2.1" after the flex joint. So having a 2.5" downpipe all the way through into a 2.5" cat back will be optimal for performance.

Price for a C5 S6 FI catback please.. I guess it would have to be custom ...maybe a bit longer than a B6 S4 exhaust. I'm ready to drive to Jersey and get one from Autospeed / ASP but would like to have options.

Price would be similar to our b6 s4 system. $1250 plus a little extra for shipping depending on where you live.

Factory spec C5 A6/S6 4.2s should both have the same 2.73:1 final drive ratio while AFAIK B6/B7 S4s with automatics would have a shorter 3.54:1 ratio instead.

Factory spec is closer to a 3.7, I forgot the exact number when I took my stock differential out but it is not a 2.73 ratio

[Scotty@Advanced]

Factory spec C5 A6/S6 4.2s should both have the same 2.73:1 final drive ratio while AFAIK B6/B7 S4s with automatics would have a shorter 3.54:1 ratio instead.

The C5 autos have a 3.70 rear end ring and pinion ratio. The trans (front diff) has a lower ratio but there is an additional transfer gear set in the rear of the trans that alters the front ratio to match the rear.

[beemercer]

So Dan, any updates to this thread? I've been hearing about a few very exciting developments for new products...

[Hambone101]

Dan, I had another question for ya, what is the turnaround time if I send in my dps into you for the "piggie" set up?

[jaybquick@JHM]

Dan, I had another question for ya, what is the turnaround time if I send in my dps into you for the "piggie" set up?

If you coordinate with us and we know when it is coming it can be shipped out the same or next day. Worst case a couple days.

[beemercer]

Just thought I'd update this thread... it's taken a redirect to the East Coast. Expect some more developments in the near future

[beemercer]

Teaser... what might these be...?

[ACHAHockey]