Gen 4 (2008-2010) Viper Issues/Requests

[ElecTech]

has anyone used an aftermarket camshaft with these engines yet, since we have control over cam timing we can minimize the "lag" of a bigger camshaft. I have a full bolt on and looking to get more power out of it NA.

I think Keith's track car has a cam(s) in it. Maybe he can provide some feedback.

[Keith@HPTuners]

My car has a larger cam and is fixed (no VVT). Runs like a champ.

[SultanHassanMasTuning]

^details can be for GenV?

[Keith@HPTuners]

Mine is a Gen IV. I don't know many others modding their vipers pretty hard. The viper community is pretty hush hush.

[MeentSS02]

Mine is a Gen IV. I don't know many others modding their vipers pretty hard. The viper community is pretty hush hush.

Agreed...ain't no one sharing nothing around here. I'm assuming requests for additional features are coming from more people than just me though, correct?

[MeentSS02]

has anyone used an aftermarket camshaft with these engines yet, since we have control over cam timing we can minimize the "lag" of a bigger camshaft. I have a full bolt on and looking to get more power out of it NA.

Have you had any luck messing with the stock cam timing? I've messed with it on mine, but don't have a readily accessible dyno to back anything up...

[SultanHassanMasTuning]

no gains regarding the exhaust cam timing.

[zr1driver]

at Gen V i also have not seen power playing with the exhaust cam Timing.
with intake and headers i found 47PS and 67Nm. i think the knock sensor pick up the headers noise because i have knock Retard with the stock spark tables on 93oct.
it would be great we have some tables for the knock sensor sensitivity and torque Management.

[MeentSS02]

Bumping for some mid-winter love.

[Dasilva Motorsports]

I have a 2008 viper on the dyno right now. It has headers and intakes. It took 3 tries to get the throttle relearn to take using the beta 3.1. I adjusted the maf curve to suite and the trims are within (+-) 1 or 2 percent thru the curve. The car drives perfect under normal driving conditions but when I go for a WOT it only goes up to 4000rpm and closes the throttle blades and throws ETC codes. Seems like I'm still having throttle relearn issues... any help would be greatly appreciated.

[MeentSS02]

So it is going into limp mode...which version of limp mode does it go into? Spitting and sputtering, or just reduced power and no more than 2k RPMs (this particular one will shut one throttle body and let the other open some)?

If you've messed with the throttle tables at all, start by putting those back to stock and see if the problem persists. You can tweak the Throttle % vs. Area table some to make sure the throttle bodies are opening all the way (mine weren't), but if you adjust it too much it'll go into limp mode.

These cars are very finicky...they do not tolerate intake modifications very well, but we can generally work around that with the tools we have available. When I did the throttle relearn last December, the first time I did it wrong...the car started, but would take no throttle input period. That's when I tried again and it took. I haven't tried the 3.1 beta version, so I'm not sure how much different it is.

I'm sure you'll get it figured out...just takes a while.

[Keith@HPTuners]

I doubt the limp mode is related to the relearn process. It's a pretty straight forward relearn.

It's likely related to your tune.

[Dasilva Motorsports]

I going into the spitting and sputtering limp mode. wont even hold idle.

I hope its not the tune, as it did it with the original tune supplied by HP Tuners. I had modified the MAF curve to see if that would fix the problem but that was the only table I modified and it didn't help at all. I also did the relearn again to see if it would fix the issue but after I did the relearn again it goes into limp mode right away now again. I did the relearn several more times and it wont take again, barely idles now. Getting frustrated with this Dodge product lol. I could have tuned 2 dozen heavily modified LS vehicles in the time it has taken to get this thing absolutely nowhere lol.

[MeentSS02]

Can you post a detailed description of how you are doing the throttle relearn?

[Revolution]

thinking of dusting my HPt PCM off my shelf anyone having any luck with it on the Gen 4

[Dasilva Motorsports]

Meentss02, I want to thank you for taking time to lend me hand.
I am doing the throttle relearn like this..

Key on, connect to scanner 3.1.
Click on VCM controls, click on the Throttle relearn tab.
I get the pop up for "wait 10 seconds" and also "wait 3 minutes" ( if I continue before the 3 minutes has past it pops up "vehicle init fail") and sometime even if I wait 3 minutes it says "vehicle init fail"
If it continues (after 3 minutes) to the next step I hold the throttle pedal down as instructed and click "ok". Then lift pedal as instructed and click "ok".
Pops up turn key off for 10 seconds (which I do) then key back on and click "ok".
It pops up "throttle relearn successful" and I key off.
I wait a minute and try to fire it up and it wont even idle.

I loaded the HP Tuners "HO" tune in and fired it up and it ran perfectly until I did the throttle relearn the first time. its been a mess since. I have read that some guys didn't do the relearn and had no issues. I kinda wish I didn't bother with the relearn.

[MeentSS02]

Try something for me...when it says that the relearn was successful, leave the scanner connected and start the car (don't turn the car off then back on). When I did the relearn on mine back in December using a very early version of that tool, that's how I did it and it worked perfectly...as soon as it said the relearn took, I started the car immediately.

[Dasilva Motorsports]

Ok I will try that. I wont be able to until later today. Thanks for the tip Meentss02. I will let you know if that fixes it up.

[MeentSS02]

Since it was in limp mode, you'll need to reflash the file first...trying to do a relearn without doing that first probably won't work.

Try this:
1. Flash the last file you used...you could also use the stock H0 file
2. After it finishes, turn the car off, then back on, but don't start the car
3. Do the relearn as specified above

[UR50SLO]

We have the RoadRunner up on the dyno yesterday with the 08 Viper engine.

If I leave the MAF's unplugged it runs and drives very normal but only 20% throttle.

I had to make my own MAF pipes... I used the stock style MAF's... But they are up front of the core support with a K&N before each.

When in Scanner The sides are pretty close to the same numbers....

The numbers however are ALOT lower than the stock numbers... Meaning we needed to take fuel out. The pipes are 3" and 3.5 just before the cards where the

Filters attach.

Now.... We plugged in the MAF's .... Tried to go on and at about 1800rpm it would start the spit and sputter/limp thing....

Once we took down the numbers in the MAF scale we've gotten up to 4000rpm before it would spit/sputter and hold at 1300rpm.

If we shut it down... and re-start it's back to normal....

What if any procedure can we follow that will accuratly get the MAF scale to be correct and not trigger the limp sputter?

Thank you very much... I am heading back over there this afternoon to try and get it worked out..... It leaves for TX next Wednesday.

~Scott