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Why does the 91CAI tune work better than the 93CAI tune?

Posted: Wed Sep 03, 2008 2:29 pm
by maansman
I know it's not just me. It seems that many folks who have the SRT, seem to get a lot of KNK when data logging, and usually have to add fuel, or play around with the settings when using the 93CAI tune.

I have a CAI, and I only put 93 Octane in my car. When I loaded the 93CAI tune, the car did not seem right. It seemed sluggish to me. Did some logging, and the KNK was all over the place.

Loaded the 91CAI, and it's a world of difference. The KNK readings are low, and only at WOT, and the car seems more responsive.

So, even though the 91CAI seems to work for me, what gives with the 93CAI tune? Is it me? Any suggestions on how to make the 93CAI work well without a custom CMR?

Thanks,
- Mark
-----------------------------------------------------------------------------------
2008 Dodge Charger SRT8 w/ Mopar CAI.

RE: Why does the 91CAI tune work better than the 93CAI tune?

Posted: Wed Sep 03, 2008 2:42 pm
by mikel
This topic has been covered to no end, but the only difference in the tunes is the amount of timing being commanded.
If a particular car does not like the 93 tune, it means it does not like the extra timing of the 93 tune. This could be because of sub-par fuel, or more likely in the case of SRT8s, oil in the intake as a result of the poor PCV system on these cars. Adding a catch can will help alot.

RE: Why does the 91CAI tune work better than the 93CAI tune?

Posted: Wed Sep 03, 2008 5:27 pm
by SRT8Tech
Yep, the SRT8's are picky sob's when it comes to timing. You NEED damn good fuel and a catch can for the 93cai tune. When I had my CMR tune done we messed around with the timing on the 93CAI tune for shits and giggles and by just changing (lowering timing) in a couple of cells in the mid range it made a differance in the whole RPM range. Picked up about 6HP in the whole range. We ramped the timing in a little slower. Picky ass 6.1!!! Aventually we got my KNK down to less than 1*. I can tell you guys that the 93CAI tune is pretty damn good when you use good fuel. It wasnt easy getting more HP on my STOCK SRT8 from my CMR over the canned 93cai tune. It all came down to the crappy fuel I have here in Jax FL and had to do the CMR tune around that fuel.

Re: RE: Why does the 91CAI tune work better than the 93CAI t

Posted: Wed Sep 10, 2008 1:51 pm
by 69rrbruce
[quote="....... When I had my CMR tune done we messed around with the timing on the 93CAI tune for shits and giggles and by just changing (lowering timing) in a couple of cells in the mid range it made a differance in the whole RPM range. Picked up about 6HP in the whole range. We ramped the timing in a little slower. Picky ass 6.1!!! Aventually we got my KNK down to less than 1*. ....quote]

Maybe DS should make these same adjustments??

Posted: Wed Sep 10, 2008 2:01 pm
by crazytrain
Hey SRT8Tech, I have an 08 Challenger and am also using the 93CAI tune and had Tony G. do a CMR on it. We got a few more ponies but not alot. Are you running the 91CAI or 93CAI and what gas do you use here in Jax?

Posted: Wed Sep 10, 2008 2:23 pm
by SRT8Tech
crazytrain wrote:Hey SRT8Tech, I have an 08 Challenger and am also using the 93CAI tune and had Tony G. do a CMR on it. We got a few more ponies but not alot. Are you running the 91CAI or 93CAI and what gas do you use here in Jax?
The base tune we did the CMR off of was the 93cai tune. Its pretty much totally redone in the timing and fuel at this point. We also messed with the KNK sensors in the CMR too. I use HESS which is right down the street from me. Not the best in the world but since its close to me thats what I use. The heat was the killer while doing the CMR. Nearly 105 in the shop and over 70% humidity. It was hard to gain anything in power in those conditions. Here are the results from the tunes. Stock was 368, 368. 93CAI tune was 370,372. The 91CAI tune was 384, 382 and the CMR ended up being 395, 393. Also the 93cai and stock tune was done with a paper filter installed. The CMR and 91cai tune was done with a K@N installed. We figured out that the K@N was a gain of 6hp and 6TQ so the CMR was a total gain of 20HP over stock and 11hp over the 91cai tune. SO basically my CMR gained me 11hp over the Canned Diablo tune. Its really hard to gain much over the canned tunes on a basically stock SRT8 in the heat conditions and fuel I was using.

The biggest thing that I saw in my CMR was the 11hp gain across the WHOLE RPM RANGE. It just wasnt a peak hp gain.

Posted: Wed Sep 10, 2008 2:24 pm
by fordomatic69
I have a 5.7L and it used to do the same thing before the catch can. I never really cleaned the Throttle Body after I got the catch can because I was afraid that the Throttle body cleaner chemicals could damage the intake or engine so I just left it.... I have never gove above 4* of KR since putting on the catch can and that was at WOT shift so I suspect it was "Shift Knock" aka "False Knock". I was even running a "test" tune from DS months ago which I believe is now called 9r07 (aka 9r08) :lol:

Re: RE: Why does the 91CAI tune work better than the 93CAI t

Posted: Wed Sep 10, 2008 2:24 pm
by SRT8Tech
69rrbruce wrote:[quote="....... When I had my CMR tune done we messed around with the timing on the 93CAI tune for shits and giggles and by just changing (lowering timing) in a couple of cells in the mid range it made a differance in the whole RPM range. Picked up about 6HP in the whole range. We ramped the timing in a little slower. Picky ass 6.1!!! Aventually we got my KNK down to less than 1*. ....quote]

Maybe DS should make these same adjustments??
[/quote]

What works on my car might not on another. My CMR might run like crap compared to the canned DS tunes on another car.

RE: Re: RE: Why does the 91CAI tune work better than the 93C

Posted: Thu Sep 11, 2008 2:52 am
by 05MAGNUMRT
FYI:

Catch can, which I have: http://www.billettechnology.com/Merchan ... formanceLX

Safe way to clean your TB, which I'll get soon: http://www.run-ritestore.com/Detail.bok?no=3

RE: Re: RE: Why does the 91CAI tune work better than the 93C

Posted: Thu Sep 11, 2008 4:15 am
by Quick
You shouldn't have to clean anything. Once you get the catch can on there you're going to stop the oil that was going into the manifold. What was already there is going to dry up or get burned like it was before. You might be left with some "varnish" in there but that's not going to effect much of anything.