'07 Charger SRT8 dyno... low numbers?

[kwaziekeller]

'07 Charger SRT8, Bassani catback, GS Motorsports CAI, 180t-stat, Diablosport... It was 37deg or so, 920am (or so), and I just got off the freeway with a 10-15min cooldown. No fans blowing on the radiator, hood up. It's a Dynojet, and I don't know if the numbers are corrected/uncorrected (looking closer, at the top it looks like the correction is SAE and smoothing is at 5).
"Red" run was in 3rd, "Green" in 4th. No AFR's, wasn't datalogging (shame on me). The giant spike on the first run was it shifting to 4th. Aside from the bottom line (horizontal axis) being speed instead of RPM, the graph looks "ok". To me it looks pretty normal, for an N/A engine and very similar to the stock "curve". I think the numbers are a little low though (~330hp/350tq, the 350hp is a spike). I've seen a lot of guys ~400whp with similar mods. I wonder if it was just the cold air (too cold for good hp numbers?), hot engine (near 200deg by 2nds run), lack of airflow (no fan on it) or if it was simply because of the reduced load on the engine... I wish 4th ran out to 180mph haha. I'll dyno again here in the spring, once it's a tad warmer, just to compare numbers and maybe tune a lil.



Since I've figuered out the view/record stuff on the Predator... and in a 2nd gear run with the r20 "93oct CAI tune" I was getting 4-4.5deg of knock retard... so I might richen her up a lil.... but DS just put out a new update 9r01 too... comments?... discuss!

[mikel]

Well, first off, what revision was this?
What was the A/F ratio? Thats the whole key....and main reason to get it on a dyno, as numbers mean very little...

The KR could be crappy fuel, or the car being too lean.
The latest revisions have more fuel at WOT in the CAI tunes, that may help if not currently in there.

Last, but not least, if going to the dyno, why not start with the stock tune, then add the tune so you can see the gains?
That leave little to second guess about.
If the stock numbers are low, and you pick up 15-20rwhp with the tune, then you know it was just a low reading dyno.

Thanks
Mike

[kwaziekeller]

I know, shame on me. I've since dynoed the car and got 371/375 out of her and was more more satisfied. I changed to a different intake and did some road tuning, I think I wound up adding 3% WOT fuel across the board to cut the LT KNK RTD. I've since added a Procharger P-1SC-1 kit (and wideband/boost guage) and am running their "base" tune. I plan to get back to a dyno soon and data log the runs. I know the Procharger tune is running pretty rich even for F.I. cars, as I usually see 10.2-10.6 @ wot, but I don't plan on pulling fuel/adding timing due to the volatility of these engines.

Mike, I know it kinda seemed like I was disappointed with the Predator, and I'm definitely not. I know throwing a graph up here without enough data to back anything up and saying "low numbers?" seems like disappointment. I'lll b sure to include all of the data I can if I make such a post in the future. I'm looking forward to getting this car to the track and on a dyno now that she's got a few more ponies in her stable

[mikel]

good deal...enjoy

[KJ2132]

Well, first off, what revision was this?
What was the A/F ratio? Thats the whole key....and main reason to get it on a dyno, as numbers mean very little...

The KR could be crappy fuel, or the car being too lean.
The latest revisions have more fuel at WOT in the CAI tunes, that may help if not currently in there.
Last, but not least, if going to the dyno, why not start with the stock tune, then add the tune so you can see the gains?
That leave little to second guess about.
If the stock numbers are low, and you pick up 15-20rwhp with the tune, then you know it was just a low reading dyno.

Thanks
Mike

So in the lastes crom posted, you state there is more fuul added @ WOT in the CAI tunes. If so, I just added a CAI on my 2008 300c SRT8 and wonder if I need to update the crom to get better performance out of the 91 CAI tune.

Let me know!

[concoursd]

KJ, the post was back in March 2008. Depending on when you bought it, you probably have a newer crom already installed and therefore do not need to worry about that.

[KJ2132]

No there was a response to this the other day. The latest CROM is what is metioned above and the post date was 10/21

[concoursd]

kj, not to really argue, but MikeL's response, the one you quoted, was March 2008. Since that time, the SRT8 in question had a Procharger installed and a different predator altogether with different revision and tuning for the supercharger kit. I was just saying that you may already have the updated tuning if the crom on your predator is newer than 2008.

[KJ2132]

Got you! My bad. Didnt see the beginning post and just looked at the last response.

[concoursd]

no problem man. I just didnt want you to waste your time updating the predator for a tune change that was being discussed that probably wont apply to you.

[kwaziekeller]

Sorry to confuse you guys but yea... that was forever ago. I just came back on here and wanted to clear things up with MikeL since I didnt want him to think I was disappointed or upset with my results, and also acknowledge that without the proper data a dyno chart cannot determine was it going on (AFR's, knock, heat soak etc). I know DS has made several crom updates since my original post, so it being brought to the top may cause a lot of confusion.

After that dyno (original post) I data logged and was getting some LT KNK RTD, so I added a lil fuel. I don't remember what revision it was as it was quite some time ago. Eventually I dyno'ed again (I go to a lot of dyno days) with a different intake (AFE II vs GSM) and got 371/375 which was more along the lines of what I expected. The guys cracking 400whp with similar mods were on custom tunes vs my car on the can tune. Again no AFR's, data logging done during the dyno, just slightly better numbers.

I recently put the ProCharger on and its actually the same Predator handheld (the one that came with the kit I'm selling to a coworker). I just sent off my factory tune to ProCharger to be edited, and they sent it back to me. This is now my "base" tune for the S/C kit. I have a wideband now and can get an idea of my AFR's, and I have data logged as well. I'm planning to dyno again sometime, possibly a custom tune, and get to the track for some new times.