Apexi-SAFC installed on Viper

[davem]

Guys,
I installed an Apexi Super AFC on my Viper this weekend. This is basically a sophisticated ROE VEC built for the import crowd. I figured it would work very well on a Viper, and it did. It allows tuning of the air/fuel ratio - but instead of coarse knobs it lets you tune the a/f ratio vs RPM and throttle position, it datalogs and had a nice large blue graphic display which can act as guages, graphs, or numbers.

I've loaded a few pics of the screens on my web page, and will put the dyno curves up as soon as I can scan them. Basically I did it as an experiment to prove it would work, picked up 14 whp after 5350 rpm without spending a lot of dyno time on it. I was able to move the a/f ratio wherever I wanted (leaner or richer), and at 6000 rpm changed it from stock 10.78 to 13.0, where the car made an extra 14whp - I tried leaning further but it dropped off. My Viper is stock, I think some of the more tuned Vipers would benefit greatly because it offers a level of detail over the ROE VEC - you can tune a/f at specific rpm and throttle points, not just a high/low window...

The afc and VEC work the same way, buy intercepting the map signal and changing it. Neither control timing, they just "fool" the ecu into moving onto a different load map, which has different timing curves - I think that it is misleading to imply the VEC controls timing.

screens in my GTS:
http://www.cmperformance.com/images/afc3.jpg http://www.cmperformance.com/images/afc1.jpg http://www.cmperformance.com/images/afc2.jpg http://www.cmperformance.com/images/afc4.jpg

later,
Dave.

 

[treynor]

Dave,
Other than the obligatory scolding for using a "Rice" performance part on your Viper

that's very cool. Do you have install instructions and/or wiring photos for others who may want to follow in your footsteps?

 

[THEMASH]

WOW, never thought of that. I have that same Super AFC on my TT Stealth.

 

[Wolf]

Davem,

Can I get some details of the install? I checked out the Apexi site online and could find some documentation, but there is no information for the Viper, was the wiring complicated to do or is there an adaptor that you used?

Thanks

 

[KenH]

Very interesting! Apexi makes some good stuff. Definitely give us more details on the hookup you used.

--- Ken

 

[utahviper]

How much did it cost and how hard was the install? It looks pretty nice and it would be nice to tune my car on the top end. Great post!

 

[davem]

Guys,
I threw together a quick page from my notes on how to hook up the AFC. I'll add detail when I have time. The AFC's go from 350-400 or so new, I usually stock one or two (however, the import guys are selling them for $150 used around here now that the AEM plug and play ECU's are shipping). The install is pretty easy, an hour or two at the most now that I have it figured out. I'll produce a complete tune for it this week and post it when I'm done if anyone wants it.

enjoy,
Dave.
http://www.cmperformance.com/viper.html

 

[Wolf]

Davem,

Thanks for the information!

 

[kverges]

THIS is the type of useful, technical information that we just don't get enough of on this site! Kudos!

 

[1TONY1]

Thanks Dave. Will look forward to seeing the dyno sheets and the complete tune. ta

 

[Miles B]

Excellent work! I had been wondering if one of these would work on a Viper. The Blitz id ones are pretty cool too... but I think they only make a boost controller not a AFC. Now we can go the Supra way with the bolt-on blower kits... bigger injectors, lines, pumps, up the boost.. I love it.

Once again, thanks!!!!

<FONT COLOR="#ff0000" SIZE="1" FACE="Verdana, Arial">This message has been edited by Miles B on 10-29-2002 at 02:16 AM</font>

 

[onerareviper]

GREAT POST!! THANKS!!!

Keep us posted on any further developments....

Later

 

[Sean Roe]

Hi Dave,

You wrote "The afc and VEC work the same way, buy intercepting the map signal and changing it. Neither control timing, they just "fool" the ecu into moving onto a different load map, which has different timing curves - I think that it is misleading to imply the VEC controls timing."

When you alter the load calibration setting the PCM is using you are altering both fuel and timing. To the greater extent, the fuel, but timing does change also. A decreased load calibration (a value you can read when linked to the PCM with a scan tool / software) means decreased fuel and increasd spark advance. It's not misleading to say that these products alter both fuel and timing. Just do a dyno pull, record the spark advance over RPM and you'll see. Sounds like your gains with the Apex box were about the same as the VEC1.

Sean

 

[kverges]

Great work by all! I still await something like the TTS and LT1edit software that has been available for the Corvette for literally years and years and allows direct changes to the fuel and timing maps at all load levels; then you simply re-flash the PCM. No splicing, heck you only plug into the diagnostic connector. Then you can data log with anything from Diacom to Autotap. Yet no one has made a similar tool available to the Viper consumer (Dodge vehicles can and are reflashed by factory tools and some aftermarket "witchcraft"). I have long been mystified by $3000 exhaust systems when precise control of fuel and spark can make comparable gains and make enormous gains in combination with modifications - and make those mods safe. Yet no one has developed and marketed a true computer reprogrammer for the user. Lt1edit is only about $100 or so. I'd gladly pay $1000 and probably more to have that power with my computer.

Is it a technical barrier or just return on investment, I wonder.

 

[davem]

Keith,

Good luck getting anything from these guys, I have tried. But they claim they can do j-tec ECU tuning....
http://giwasa.virtualave.net/viper_ecukit_gb.htm


I am working with a vendor now developing a standalone plug in ECM that will use the stock harness + crank triggering scheme.


Sean,
I see your point, thanks.

later,
Dave.

 

[jcaspar1]

Did you see that on their webpage they state they ran a 8 sec 1/4 in their Viper!

"The GTSRR GIWASA , a supercharged 1200 HP Viper totally streetable for many miles ,

or for track races , close to the factory GTSR option , big brakes , short ratio gear 6 speed

non syncro super fast shifts , carbon light body 1.300 kgs (2.850 lbs) , close to 240 mph

8 sec on 1/4 mile"

 

[treynor]

&gt; Did you see that on their webpage they state they ran a 8 sec 1/4 in their Viper!

*cough* ******** *cough* *hack*

Look at this picture of their "8-second" viper. Stock wheels, stock front crossmember (so where does that enormous supercharger fit, exactly??), "big brakes" which are not compatible with 8-second passes since you can't fit 16" drag wheels over them, etc.

You must be registered for see images

 

[Greg D]

Anyone know where (else) I can get an induction system like the Ten Throttle Body Kit GIWASA advertises? It's killer looking and garunteed to be unique at least for a street car).

You must be registered for see images

Came across this while cruising their (GIWASA) site, hope it wasn't the result of a test drive of their 8 second 240 MPH supercar.

You must be registered for see images

I guess you just drop your car off (like these guys are doing) and wait for them to turn it into a 8 second 240 MPH supercar!

You must be registered for see images

 

[SVS Turbo]

What is it that makes a balloon go up?


Jr.

 

[KenH]

These are the same guys that advertise 8 tube headers for the Viper. Probably part of their power secret. Direct venting one of the 5 cylinders on each side help induce a special scavenging effect.

--- Ken

 

[Eddie N]

no air/fuel controllers are model specific but during the install you must be patient and know which wires to tap into..

for years i have been saying "when are people going to start combining import technology with the big cubes of domestics?".. imports squeeze at least 700 hp out of 3 liters.. imagine that same technology applied to 8 liters... now of course not everything can port over (like 8000 rpm redlines), but the electronics and total control over every aspect of fuel, timing, boost, etc can..


congratulations to davem.. finally someone seems to have taken the initiative.. i'm curious about this stand alone viper ECU.. will this be an aem unit?

- eddie -

 

[v8huntr]

i have unichip in my car. unichip can change fuel and timing. it's about $800.00 installed and tuned.

<FONT COLOR="#ff0000" SIZE="1" FACE="Verdana, Arial">This message has been edited by v8huntr on 12-19-2002 at 10:46 PM</font>

 

[v8huntr]

new and better apexi s-afc is coming out end of this month.

http://www.takakaira.com/asp/template.asp?id=815&cat=2