Roe SC and Cylinder #10

[KenH]

As most people know, there is an air restriction on the #10 cylinder with the Roe setup. That causes the cylinder to run extremely rich compared to the others. Rich enough that the plugs foul out and the cylinder is dead in my case. What I don't know is if the airflow changes much between vacuum and boost conditions and therefore if you treat the vacuum conditions you are harming the boost conditions. A black plug doesn't bother me, a dead cylinder does.

Curious how most people are dealing with this?

1) Continue to lean out that cylinder with the individual injector trims until it no longer fouls the plug. I know some people on here like Schulmann are taking that approach, but not sure how successfully. I have backed my trim down to -1.0mSec, but it has not seemed to make any difference. I would hate to run that cylinder lean under boost conditions if the airflow is different.

2) Run a hotter plug in that cylinder. If so what plug? I have heard that some may be running the stock plug in that location.

3) ?

 

[Schulmann]

Kenh, well come in the super tuner's club ... It seems that only a few serious tuners think about cylinder #10.

Cylinder 10 gave me a lot of headache and took me to buy hundreds of spark plugs. I got addicted to spark plug testing like some people get addicted to ******.

Basically you have to learn to live with this problem. This low rpm problem is related to the short runner design of this type of supercharger. Only under certain RPM this problem occurs .


So this is how I handle this issue:

- I have two programs: one for long trips on highway and the other for racing

- In the hwy program I remove as much as 2.2ms fuel from cylinder 10 but still cylinder #10 runs rich.

- in the race program I "only" remove 1ms fuel from cylinder 10.

- Under 1700rpm and vacuum cylinder #10 runs always rich

- Between 1701rpm and 2000rpm and vacuum cylinder #10 runs perfectly, but with my sever fuel trim it run 15.6AFR

- From 2000rpm - 3000 rpm and under vacuum all cylinders will run very lean around 17AFR

- When making long highway trips, I always cruise around 85mph which is around 1720rpm and cylinder #10 runs very well with the 2.2ms fuel trim (plug tip gets nearly clean ).

- When driving in the city (short trip) I alway drive between 2000rpm and 3000rpm. This type of driver does have much consequence on fuel consumption. Cylinder #10 is still black but plug tip gets nearly clean.

- I alway use 94 octan fuel, it reduces risk of detonation in cylinder #10.

- A couple of days before racing I make a combustion chamber cleaning in cylinder #10. Then I drive about 50mi to remove all the cleaner from the cylinder. This cleaner removes everything event the thin oil film ... But it is clearly explained on the bottle.

- If I want to race on the highway. I just run the car at 3000rpm a couple of minutes so everything gets clean.

- In my case I use NGK plugs. My viper prefers the NGK FR4. However FR5-1 seems to be good also. For racing I use FR5.


Kehn, a question: Did you changed your cam ?

Have a look also on this post.

I hope that other tuners will also share their experience with this infamous cylinder.

 

[Sean Roe]

Hi Ken and Andras,

We were shorthanded this past week and I wasn't able to get back on here until now.
Before you do too much with worrying about the sharp change in the injector duty cycle log or the fuel trim of #10 cylinder, drop me an e-mail with your VEC2 box numbers.
We have a new firmware and software that will be ready for release in the next couple of weeks and I'd like to let you guys run the Beta version. I've run it on three cars in the shop we did this past week.
There are several functionality and logging improvements (such as better fuel trim management, HP and TQ logging, injector duty cycle signal filtering, etc). Drop me an e-mail at [email protected] and I'll get you the firmware and software for evaluation.

Regards,
Sean

 

[Supercharged Vipermad]

Sorry to hijack the thread...but...

Sean,
How do you notify us VEC 2 owners there is new software? Is it typically something we will all see an advantage over what we have now?

 

[Sean Roe]

Once we finalize an improvement / update to the existing software, we put up notices on this site and contact people by e-mail or regular mail.
The newest software and firmware versions are always on our website.
Current software is version 3.5.0 and current firmware is 5.79.
We're using software 3.5.3 and firmware 5.107 on three cars in the shop now.
I'd like to get input from a few more people before releasing it to all 650 current VEC2 owners.
As usual, there will be no charge for the updates and upgrades.

Regards,
Sean

 

[SUN RA KAT]

I pulled my plugs a week ago and all plugs looked perfect, except #9 and #10, which were both black. I cleaned plugs #9 & #10 and put them back in and my Viper runs great. I'm looking forward to a permanent solution to my #9 & #10 problem.

BTW - This was after 1,000 miles of driving on my plugs.

 

[KenH]

Schulmann, thanks for the detailed response as usual. I agree, it would be nice to get more detailed info from some of the others who are doing their own tuning.

I am running the stock heads/cam/rockers

Sean, I'd be happy to test the new software/firmware. Email sent.

--- Ken

 

[1TONY1]

Schulmann, thanks for the detailed response as usual. I agree, it would be nice to get more detailed info from some of the others who are doing their own tuning.

I am running the stock heads/cam/rockers

Sean, I'd be happy to test the new software/firmware. Email sent.

--- Ken

Ken....Just checking, Do you have the MSD injector connectors ? Have you verified all injectors are firing ? Have you checked #10 exhaust with a temp gun to make sure it is not firing (it may be colder temp but still could be firing)

I ask this because if there is another problem the miss "could" be somewhere else and like I did for months...it's easy to concentrate on that black plug when it possibly is not the problem.

 

[KenH]

Tony,
Yes, I spent 6 hours about a month ago tearing things down and putting the MSD injector clips on to make sure that was not a problem. I bought a mechanics stethoscope and tried to verify proper injector firing with the stock injector clips, but it was too hard to draw any conclusions, so I figured better safe than sorry. I do feel that the car has run a little more reliably since the injector connector swap-out, so I think it was time well spent. I just wished my installer would have done it the first time.

I have used a thermocouple to measure the header tubes when the engine first fires up and #10 stays cooler longer, though it actually gets hotter once the car is run for some time. It obviously has run too hot at times as #10 has also burned the ceramic coating off. When the car is first started and I put my hand over the exhaust pipes, the driver side has even pulses which all warm up together. On the passenger side, I can feel a cylinder pulse that feels erratic and that contines to stay cool as the others warm up. If I then shut the car down and pull the plugs on that side, the only one that looks like it has a problem is #10. What I don't understand is that it doesn't look wet as I would think it would. If I replace the plug, then the car seems to run OK for a while. It's possible that #10 lights off once the car has heated up, but the car seems to be down on power which comes back with a plug swap.

I have tried the Bosch, Autolite and now NGK Iridium plugs to try to see if any would perform better. The NGKs actually run much smoother, but still fouled out.

Out of the 1/2 dozen or so problems I started with, I think I am down to two. This one and the one on the other thread where my injectors tend to go to 100% duty cycle intermittently, flooding the engine out. http://vca2.viperclub.org/forums/showflat.php?Cat=&Board=UBB14&Number=589448&page=3&view=collapsed&sb=5&o=&fpart=1

--- Ken

 

[KenH]

Sean,
Can you give us any info on the types of changes that have been made in the new firmware/software?

 

[99 R/T 10]

I am running with the stock heat range plug in the #10 hole, and have had good results. I actually use the Splitfire SF98E, but if I am on the track with NOS, I will switch it out with the colder plug, but on the street it works great. Ken, if you want, PM me your address and I'll send you one to try.

 

[Jack B]

KenH:

Take a look at the Final GTS posts on the new SRT plugs. I am using the SRT10 plug, but, two heat ranges colder (RC10ECC). It is an extended reach plug, however, colder. Our cars don't like the standard (short reach) plugs and this is all that has been available in a colder plug till the new SRT10 plugs came out.

I have used several types of colder plugs and I can tell immediately the car doesn't like the plug upon start-up. Due to the extended reach this plug is hard to tell from the oem plug, yet it is much colder and safer to use on both nitrous and cars with boost.

 

[99 R/T 10]

Jack,
how does the RC10ECC run on the street under normal driving conditions? Any of the plugs fouling?

 

[Viper Specialty]

99 R/T 10- I am running these plugs on many street cars, I have not yet had a fouling problem, even when running them on near-stock cars. I have 2 sets left in stock, and more backordered- as usual.

 

[Schulmann]

I have tried the RC12ECC which is hotter and cylinder #10 still fouls .... so the problem is elsewhere.

 

[BlueGTS]

What is the part number for SRT10 plugs only one heat range cooler? For a normal 8psi ROE car would 2 heat ranges be necessary? I was very reluctant about putting the short reach plugs in and even gave a call to Dave a ROE when I was installing. Now that there is an alternative it is worth a try. Now should I go 1 heat range or 2?

 

[99 R/T 10]

One heat range colder would be RC11ECC, just check around your local parts store.

 

[KenH]

KenH:

Take a look at the Final GTS posts on the new SRT plugs. I am using the SRT10 plug, but, two heat ranges colder (RC10ECC). It is an extended reach plug, however, colder. Our cars don't like the standard (short reach) plugs and this is all that has been available in a colder plug till the new SRT10 plugs came out.

I have used several types of colder plugs and I can tell immediately the car doesn't like the plug upon start-up. Due to the extended reach this plug is hard to tell from the oem plug, yet it is much colder and safer to use on both nitrous and cars with boost.

Yeah, I have been thinking about it. I was hoping to get a few miles on my $100 Iridiums before I threw them in the trash. I have tried running the stock plug in cylinder #10 and that is also loading up pretty fast and I noticed that the car seems like it may be missing on a cylinder again this morning, so I don't know if just running on different plugs is really going to help me with this issue, so thanks for the offer 99RT/10 but I don't think it is going to help.

 

[KenH]

I have loaded Sean's new firmware into the VEC2 and the new 3.5.3 software. I'll see if this helps the situation any.

 

[Schulmann]

I did some testing with the new kit yesterday.
I had a trouble with my fuel so I didn't push hard the car.

 

[Viper Specialty]

99 R/T 10 & BlueGTS- RC11ECC does not exist. Also, do not think you will find RC10ECC at a parts store. I have vitually all of the plugs currently available in the country in my stock. They are VERY low production, and you will not even find them in a store's inventory system, let alone at the store itself.

 

[99 R/T 10]

Hey Final, aren't the RC10's too cold for normal street use? What is the cost of a set shipped?

 

[weed43]

The RC10ECC plug is a marine plug, and I found them at Championsparkplugs.com. there is a 8 day back order on them. the plugs are 4.15 per plug, and 8.77 shipping charge. I was told that there was a run on these plugs, LOL

 

[Viper Specialty]

99 R/T 10- The 10 heat range plugs are not too cold for street use. I have them in stock (2) for 52.50 per set.

 

[SUN RA KAT]

Does anyone else have problems with #9 AND #10 both getting blackened up like me or is it just #10?

 

[Schulmann]

Kenny, I have only trouble with Cylinder #10.
Fuel offset works perfectly on all other cylinders, including cylinder #9.

 

[Jack B]

The RC10ECC plugs do not foul on the street, the reason that the normal cold plug fouls in our cars is probably due to the reach. All the cold plugs being used do not have the extended reach, except for the RC10ECC. We should give Dan a little salute for finding this solution.

 

[Viper Specialty]

Jack- Thanks, I really do appreciate it!

Schulmann- I recomend you contact PBJ. He has an interesting fix for the infamous cylinder 10 issue directly related to airflow... while involved, it may be the fix you were looking for.

 

[Schulmann]

Thank you Daniel.
Who is PBJ ?

By the way I have done some test with the new VEC2 firmware and it seems to work very well. Definitely it improves the situation.

 

[99 R/T 10]

PBJ is Performance by Joe. Joe Donovan is out of St. Louis.