Running Rich

[V10 MOJO]

i have had corsa catback and random tech hiflo cats for a year. i just did belanger headers this past week and like another post on here, i think i may be running a bit rich. possible or in my mind? if so, other than a vec 1 which i do not have, how could i compensate for this?

 

[HP]

Probably in your mind. Unless you notice a change in spark plug readings, or
hook up to a wideband O2 - the engine signals are hard to read.
Since I hooked up my wideband 02, I realized that I had falsely attributed
some symptoms to overly rich conditions.

 

[Steve-Indy]

Have you set a code ??

 

[Steve 00RT/10]

If you set a light--you're probably running a little rich. If not, I would guess you're running just the way the computer has always run your car. I set a light(s)on my car--both for O2's and cats. On a dyno, my A/F was definitely rich. Rear O2 sims, Cragin front O2's, and a VEC1 will hopefully show different results when I dyno again this spring. Prior to having this 'equipment,' I bought a OBDII code reader/eraser---it worked slick.

Steve

 

[Steve-Indy]

Interestingly, a friend had the EXACT same setup...set a light that cleared itself, then months later noted Viper down on power on dyno, hesitation when getting on the gas, and black smoke with acceleration...NO LIGHT set...BUT, upon analysis showed that idle air motor was out, and he was running rich as a default. Might have Viper checked with an OBD II or DRB III.

 

[Dale Craig]

rdustman,
When I added the Belanger headers and hi flow cats, I thought the engine would run lean. The reason I thought this was, I have the UniChip installed. After adding this, the dyno shop then tunes the engine on the dyno at 300 rpm increments. This chip overrides the factory computer where settings are changed. The way I understand it, and I am no expert, where the UniChip has control, the factory chip does not learn. My car was running rich with the factory chip and after the tune I picked up 25hp at the rear wheels and the dyno slip showed that the engine was running leaner, mostly at high RPM's. So I was concerned that adding hi flow cats and headers might make this lean out more and cause a problem. So right after the install I went back to the dyno shop for a test run. The engine was back to running close to the air fuel ratio that the original factory chip.
Stock Air Fuel was between 12 and 11 from 3500 rpm to 6000 rpm. After the UniChip and turn Air Fuel stayed around 13 across the same RPM range. After the headers and hi flow cats the ratio stayed around 12 for this rpm range.
I am going to do another dyno test after I get 500 miles on this modification.
Dale

 

[V10 MOJO]

i spoke with sean roe and after some conversation, im going to do a vec 1. from what he says, the viper runs rich to begin with and for obvious reasons this is a detriment to output. so ill see how the vec 1 does when i put it in next week

 

[James Bell]

There was not a listing for any year Viper on the UniChip web sight, Dale Craig. Is there a universal kit that will work on the Viper? Functionally, it seems like a more sophisticated Vec-1 (changes fuel curves only). Have any tuners tried or used the UniChip? I do not see a lot of posts about it.

 

[99 R/T 10]

rdustman,
When I added the Belanger headers and hi flow cats, I thought the engine would run lean. The reason I thought this was, I have the UniChip installed. After adding this, the dyno shop then tunes the engine on the dyno at 300 rpm increments. This chip overrides the factory computer where settings are changed. The way I understand it, and I am no expert, where the UniChip has control, the factory chip does not learn. My car was running rich with the factory chip and after the tune I picked up 25hp at the rear wheels and the dyno slip showed that the engine was running leaner, mostly at high RPM's. So I was concerned that adding hi flow cats and headers might make this lean out more and cause a problem. So right after the install I went back to the dyno shop for a test run. The engine was back to running close to the air fuel ratio that the original factory chip.
Stock Air Fuel was between 12 and 11 from 3500 rpm to 6000 rpm. After the UniChip and turn Air Fuel stayed around 13 across the same RPM range. After the headers and hi flow cats the ratio stayed around 12 for this rpm range.
I am going to do another dyno test after I get 500 miles on this modification.
Dale

So what is optimum A/F? 13 to 1?

 

[Dale Craig]

James,
I am not sure about the universal UniChip kit. I had the Dyno Shop here in San Diego do the work. They have a web site, The Dyno Shop , you might want to give them a call.

As for the optimum A/F, I would ask one of the very good turners that post here all the time. Someone like Sean Roe would know this for sure.

Dale

 

[ewave]

I've tried to get some good technical info on the unichip, and all I found was marketing hype. Not even any pricing information. Do you know what the system costs? And did they provide you any real techinical information? What sensors and outputs does it splice into?