Vararam and tune

[bmorecam]

I thought this deserve a thread of its own since this is an issue that should be looked at seriously for some of us that have a tune. As some of you know I been monitoring my fuel trims eversince my vararam install. My LTFT at idle is about to go into 20% and at driving condition is at around 10%. This indicate a very lean condition by the ecm. After reading up on fuel trims and others with vararam, I've ran across many who say if we have a hot tune(tune thats maxed out)that we will see our LTFT go sky high and see zero gain with this intake. I know that my case is a little different, but regardless of what type of fuel I am running my ecm should be able to compensate for the extra airflow unless the tune I am running was already hot or theres something else that need to be looked at that I am not aware of.

Anyone else with a tune installed the VR yet?? if so, what is your impression so far and how's your fuel trim looking?

Mine was driving ok the other day, but now is just so so.. I dont want to start scaring peoples with this, and this can absolutely be an isolated case with just my situation but I think its defenitely something that should be looked at with peoples that already have a tune.

but here is an example where the tuner chuck cow talks about vararam and fuel trims.

Let me tell ya how it works.......

If your existing tune is "tight" and running to it's full potential....yes, it is possible that the vararam can increase your fuel trims or lean it out....

Sadly, most tuners I have found turn off the "lean fuel trim" codes which unfortunately dosen't tell the driver when fuel mixture gets too lean..... You should have the tune looked at....

If the tune is so-so and not maximized....the Vararam might not effect the tune so much..........

If your existing tune has got fuel trims in the mid to upper teens...(ie: 10-17 or so) and you add the Vararam....They will likely hit 20 and cause a fuel trim code.

If the car is tuned with fuel trims from the teens and down towards the rich side....Everything will be fine....

All in all you can put the vararam and a cat back with headers and with no tuning the fuel trims usually get to the upper (lean) limit..This is on a stock motor with no tune.

You should have a competent tuner check it....NOT ON THE DYNO. Do not tune a VARARAM car on the dyno...you're asking for trouble.

Tune it on the track or street where you actually use it.....Best advice I can give you.

Call me if you have any other questions.

[OOLIE]

Thanks for sharing I don't have vararam, but this will help many I am sure.

[montreal2010yellow]

So much to learn with time with this new CAI. I appreciate people giving their opinions and finds about this product that might need some upgrades in time, like a V2 nearby, maybe. That is one of the reason I ike Camaro5.

I would love to have this type of CAI on my car but I decided to wait a little for furthur developements.

[baup5f]

So in average joe terms are you pretty much saying you see/ feel little to no difference with the VR installed with your current version of the E85 tune? Has Vince been able to look at logs since adding your VR and send you a updated version?

I'm wondering about just the "13 HP tune." I'm pretty sure at least one other member (gopaul?) has that tune with the VR intake.

[bmorecam]

Originally Posted by baup5f

So in average joe terms are you pretty much saying you see/ feel little to no difference with the VR installed with your current version of the E85 tune? Has Vince been able to look at logs since adding your VR and send you a updated version?

I'm wondering about just the "13 HP tune." I'm pretty sure at least one other member (gopaul?) has that tune with the VR intake.

I sent vince a datalog this morning but I didnt hear from him yet, but since than it climbed another 2%.

I am patiently waiting to see gopaul's dyno numbers. If not mistaking, I think he had his dyno run today at 10am right? My LTFT been just climbing, and is defenitely not the same feel today as it was yesterday. I dont feel power lost, but I dont feel any gain either. At least not anymore. I checked and rechecked my install and everything is perfect. The fuel trim is defenitely telling me is not right and im sure my LTFT at 20% at idle I will be getting a CEL soon.

Is it me and just gopaul the only 2 who has VR with a tune within the whole community?

[usa1camaro1969]

No, brother, I got one, too.
I wanted to put some miles(couple hundred) on it before trying to send a datalog. I'll probably be sending him one this weekend to see if things look okay.

[rolnslo]

Honestly, your E85 tune is the one I was most concerned with when combining it with the Vararam intake. Vince had you set up for a certain air/fuel ratio based on your previous (stock, IIRC) intake. The Vararam flows way more air than the stock box does and if the E85 tune can't dump more fuel in (than it already has to) to keep up with it, you go lean.

I'd really be interested to hear what Vince's response is to the datalog you sent him today. Maybe the injectors can't pump enough fuel in to keep up now?

GoPaul's dyno run is scheduled for Friday morning @ 10am and I think he's just running the +13hp tune from Vince at the moment.

Just an FYI...if I remember correctly, the computer won't throw a code on the LTFT until it hits 32% (as least mine didn't until that point was hit).

If you need to speak with someone at Vararam, you need to talk with Patrick. He is most definitely the expert when it comes to what this ECM and intake combo can handle.

[bmorecam]

usa1, what is your opinion so far with the tune and the VR as far as what your butt dyno tells you?

rolnslo, Its possible.. but in my case I am lucky to be monitoring my ecm data or otherwise I would still be driving blindly thinking everything was ok until I probably got a CEL. Possibly this is just a isolated case with my e85 tune like I stated before.

Most cars usually set off fuel trim CEL within the -/+ 20-25% range.. maybe thats why I still didnt get one at 20% assuming you are right at around 32%

will see what vince say.

[usa1camaro1969]

Butt dyno says I definitely sink my butt more into the seat.
The car is more responsive at speed than before.
My iat stays right around 4* higher than on the radio display.
Debating whether I want to take her to the track while we have upper 90* weather or drag butt until October. I really want to.

[bmorecam]

Mine too.. IAT is always 3-4* higher than the radio until you are sitting or going very very slow in the traffic, than the IAT rise fast but also could be because of this upper 90* weather. Since you can monitor your IAT where are your LTFT right now?

[usa1camaro1969]

I'll cycle through and check them.

[bmorecam]

That would help.. thank you. if you can monitor LTFT at idle and while driving.

[GoPaul]

I guess this is the right place to post this but let me know if you are trying to keep this strictly to E85 tuning and I will remove.

Ok so I got a dyno today with my Vararam installed and the 13HP Trifecta tune - not the results I was looking for :(

I then uploaded the Stock tune and had 2 more runs and got a significant improvement, but I was pretty disappointed with the results all around tbh.

My benchmark dyno was 257 which was with only an Injen CAI installed (done in Oct of last year).

My first 2 runs today were with the Trifecta tune and only got 241HP - this raised up to 253 once I went back to the stock tune. The temp and humidity were pretty awful today so may have played a part and also the last 2 tunes were probably still in the relearn process and so may have improved slightly over a couple more runs.

I will be logging with both tunes and sending to Vince to see if he can sort it out but it looks to me that the 13HP tune doesn't play nicely with the Vararam :(

Oh by the way I have a lot of black dust on my exhaust since installing the 13HP tune and my avg MPG has also dropped to 19.7 (from 20.0) so I may be burning way to much fuel.

[bmorecam]

So let me get this straight, when you loaded the stock tune it got you 253 and 241 with the 13hp tune? did you give the 13hp tune's cam phasing a chance to take effect?? It will usually take about 2 dyno run before you can see the full effect of the cam phasing that are incorporated in the 13hp tune. I just went through this with my last dyno. Also, when did you dyno the VR. Could you please do me a favor and indicate which hp/tq go with what?? so I can have a clear picture of exactly how you dynoed.

I just did talk to vince and he did confirm that my tune will have to be adjusted according to VR, but not too sure if he just mean my e85 tune specifically or overall.

Also, your dyno correction factor is 1.01 calculating from your avg hp/tq's condition.