<3
<3 all around thanks CV, jake and the rest of the jhm related crews :). Must resist getting a second v10…argh what the hell 
I just sent an email. I’m local, sacramento area, very interested in working with JHM for some S6 v10 ecu/tcu tunes
Being a lurker for quite some time and joining later on the site, are you affiliated with JHM? I’m just curious because I have a suspicion V8A6 is referring to your shop with custom headers in Detroit and not JHM’s in California.
Im sure CV can answer this when he posts again. But yes V8A6 was talking about CV as the shop that makes custom headers and exhaust systems. CV and his shop actually made the RS4 systems and headers for JHM for the RS4 and S4 for years. The shop is more prototype work but they will do small production work for cars like the S6 and S8. The cool thing about there shop is everything is tested and not just random pipes with mufflers on them. It makes for a bigger better performance gain.
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What he said
Before I get too far into the performance part of the thread. It’s important to mention a very important thing and that’s maintenance.
We all know about how important carbon cleaning is, but what are some of the other big issues that seem to keep coming up but not talked about?
Injectors, there has been a good amount of talk about this lately and a good amount of talk about this quietly in several S6 threads, where people have mentioned they had one or more injectors replaced to help with a miss fire or some sort of other driving issues.
On my test runs at the track, I felt the car laying down after 6k. Some of that was the cars Tq limits kicking in but another component into that was some of my injectors were not flowing right and something in the upper RPM range was going on.
Turns out injectors are an issue that needs to be looked into when talking about performance and maintenance.
After realizing this might be a bigger issue than most knew about, I I took a minutes to investigate. I started by looking at some car faxes from current for sale V10 S6 cars to get a good idea on if this was common or not.
The good thing about V10 S6 and S8 owners is, the first and usually second owners of these cars generally took the cars to the dealership to get serviced. The dealerships have a good rate of reporting to car fax when work was done, so I felt like this would be a good pool to look at to see just how common this might have been.
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This was pulled from just the first few carfaxes I looked at.
It shows replacement of the injectors one or more. These were on cars with less than 52,000 miles
From just looking at the carfax reports on that day. It showed about 30% of all the cars were getting some sort of injector replacement or injector service.
This is something that is right in front of our faces but seems to have been very quiet for a long time.
It might not be a bad idea to start a thread just on this issue to help make more of the community aware that this is something to look into.
It’s not all bad news, there are several big things you can do to help. One of the major things you can do is to make sure to keep the car free of carbon.
It was a common practice in the past to have the dealership use a fuel system treatment to try and help with the carbon. The fuel system treatment would help remove the carbon in the injectors but it would do nothing for the carbon on the valves and in the intake.
One of the suspected killers of the injectors is carbon. So on my way to talking about the performance of my car and its results, I think the big talk is all the steps I took to help make the car safe along the way.
We have a carbon thread started here. I’ll make sure to step into that thread sometime next week to make sure I get it updated and get this entire thread more off the ground.
Going through the car fax reports like that is a pretty genius way of gathering that sort of info, nice work!
X2 that was a slick idea. Nice work.
Yup mine was this at 55k miles:
-new intake manifold, new flapper motor
-carbon clean
-spark plugs
-one new injector
- then the rest of the usual 55k service stuff, plus atf change
- plus added msds filters
The above plus already installed exhaust,meant on dry pavement and newer tires I could actually trip stability control on in 1-2nd gear, I felt the tires trying so hard to grip, which was fun…felt about 60hp faster. Or jthe same as my e60 m5 when stock in all normal driving situations up to 80 mph, although no one believes me on that one. Much more enjoyable to drive and 10x more reliable as well!
I have a binder somewhere, took to dealer for warranty and then either Jimmy or a performer shop in MD for the rest of service. I changed almost all fluids to motul but atf which is Oem.
I really want to get a carbon clean and injector clean done.
Is there a reasonable way to test your injectors before hand via vcds ?
Looks like even the cleaning/refurb and bench test is not a sure fire way of eliminating a bad injector.
The shop just pulled mine from my v10, and four out of the 10 fell apart upon removal. So I skipped the rebuild route and went all new.
what shop are you using that you trust with a carbon clean / injector work? You can PM me if you’d like.
That looks like a case of rare circumstance. Also you cant go cheap on getting the injectors cleaned. They need to be flowed at what the car would run them at. You have to find a repituable testing place
Until we see more issues like that one. I would be more likely to chalk that up to installer error or general oddity
Let me kick this into gear.
For those of you who don’t know. Here is a picture to show you where the HPFP’s are (High-Pressure Fuel Pumps) where your air boxes and throttle bodies are along with your air box.
Also, a big misconception was that these cars had an intake silencer. That’s not the case, the V10 has a symposer system that actually projects motor noise into the cabin.
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Neat on confirm of the symposer I remember finding that before and wondering if that was it or a silencer.
My first reaction was to this that was a silencer.too. The S6 guys have it on the passenger side air box I think its on the under siide. It goes from there all the way over to the driver side behind the fire wall.
Now with some of the pre-performance talk out of the way, I started getting to the heart of what else needed to be done before adding the JHM Tune.
We all know carbon is an issue but so are your plugs and coil packs. The number two reason for misfires on the V10 is an outdated or just worn out coil pack. Once the coil pack starts to get bad it will effect the burn in the cylinder and over time, it will kill the plug.
It’s good to pull the plugs and packs and give them a good once over.
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I was told my coil packs were changed recently. Turns out on inspection, that sure maybe some of the coil packs were changed but they were changed with coil packs that were actually older than the cars build date. So, this means someone put in old used coil packs. M
My car is a 09 but here this shows you how to look at the coil packs in your car and tell when they are from.
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The plugs looked original. Some of them worse than others. The fresh change of both the plugs and coils helped the car start and run better.
After the carbon cleaning and before I put in the plugs I did a quick compression test. These cars can have as high as 200 on the readings. I was happy most of my car was in the 180 to 190 range. I didn’t spend the time to do the compression test the proper way. I just wanted to get a quick idea where the compression was. The motor was cold and hadn’t been running for a few days. I had one cylinder that was lower than the others. I never went back and checked but I chalked it up to a lifter that had bled down.
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Getting closer to running through the entire maintenance gauntlet.
The next steps are installing the JHM intake spacers, the new fuel filter, checking the air filters and putting it all back together getting ready to build the cat back exhaust and then the JHM ECU and TCU tune
Looking great CV!
This has been a great read so far, CountVohn. Good stuff 