396/349 shakedown dyno runs w H/C LT1

[mpe331lx]

http://i24.photobucket.com/albums/c22/mpe331lx/97LT1.jpg


A couple weeks ago we took the Camaro to a local dyno day. It put down some pretty good numbers considering the tune needs a little work.

Here is the rundown of the combo:
T56/10bolt/3.42's/17"Zo6s w/ 275/40/17s
Stock shorblock (back yard rebuild with new rings, bearings, and ARP rod bolts)
AI 200CC Stock Lt1 heads
230/236 565/570 108lsa
Supporting valvetrain
58MM BBK TB
CSR EWP
1 3/4 pacesetter LT's W/ ORY
Magnaflow cat back (no cut out)
39lb 03 Cobra injectors (w/ev6-ev1 adapters)
autolite 104's gapped at .035
brand new GM optispark
95 OBD PCM / 95 knock sensor
Mail order tune
K&N CAI (have SLP ls1 lid and box that will be modded to fit car soon)




I dont have the dyno chart with the A/F graph (yet), but I did take a vid of the screen for one of the passes:
YouTube - 97 LT1 Camaro on the dyno

http://i24.photobucket.com/albums/c22/mpe331lx/97_camaro396349.jpg

The A/F is at 10:1 all the way through most of the RPM range and creeps up to 11.4 at the very top.
Between doing a cut out and getting the tune spot on, how much power might we have on the table.


There is a funny story to this that caused a 4 OR 5 page thread on a local forum and a 10 pager on ls1 tech:laugh:

When we decided to do a build on an LT1, most were like "don't waste your time with an LT1, they are junk". I know/knew what I could do with it and wanted to suprise the hell out of a few locals with a "WEAK ASS LT1" as some have called it.

The car put down 292/321 with full exhaust, CAI, and an EWP.

As far as everyone knew, the next round of mods was a cam and the supporting valvetrain. I left out the fact that it was getting a nice set of heads:whistle:

Once it was together, I planned on taking the car to a private dyno session, but could not pass up the deal of $35 for two pulls at the dyno day.
As far as all of my friends knew (on and off line), all I did was a cam swap.
everyone thought that the car was going to be weak stock LT1 with a cam;)
When asked what it had done at the dyno day, I had to stick to the what I told my friends (some of them were there)

One of the guys that was at the dyno day posted my numbers and "claimed" mods, and all hell broke loose, lol.

http://www.need2speed.com/vb_forums/showthread.php?t=60508

http://www.need2speed.com/vb_forums/showthread.php?t=60761
(sometimes you can see threads on that site without bieng a member, sometimes you cant, I dont know why)


Someone in one of those threads decided to post about a possible "record breaking cam only LT1" on ls1 tech:
http://www.ls1tech.com/forums/lt1-lt4-modifications/1119405-cam-only-lt1-makes-396-hp-record.html

I had no intention on posting about the cars mods or dyno numbers until we spilled the beans on what it really had done to it locally.

I planned on running it against a few locals and also the N2S's DH10 event. I wanted to leave a few people scratching thier heads wondering what was REALLY up with the grey LT1. Well it looks like I have already done that lol. Although I wanted it to be because of its performance, not it's dyno numbers:censored:

[95formula383lt1]

holy shit 396 not bad!!
i hope mine puts down something close to that with a good tune. Which dyno did you go to?

[mpe331lx]

holy shit 396 not bad!!
i hope mine puts down something close to that with a good tune. Which dyno did you go to?

RevXtreme.
I usually go to Roys at Aftermath performance in Ft Myers, but he was pretty booked and the dyno day came up at just the right time.

[95formula383lt1]

nice im too scared to drive mine that far lol its been breaking alot lately.

[1hottcamaro]

I left there kinda dissapointed cuz I didnt want it to be running rich and I wanted it to do like 415

[mpe331lx]

Added graph with A/F ratio.

[mpe331lx]

Here is Ron from AI's response about the car/numbers on LS1tech:

Happy to see the car up and running. However, as others mentioned I would have a great deal of anxiety running the car with the fueling that far off. It is clearly killing it, torque and HP are both lower than we normally see. A competent tuner, ideally in person, is vital to your success. That is not to say that your current tuner is not, but there is only so much that can be done remotely. In instances where you're utilizing heads & cam at (what should be) 120hp over stock + bolt ons it is going to be improbable any mail order tune is going to be ideal.
With a proper tune you'll be shocked at how poorly it must currently be running. With adequate inlet/exh & proper tuning that setup typically manages 420-430hp & 375-390lb-ft SAE on the DJ's. Ensure your ignition/electrical systems are functioning properly & get on the tune before you hurt it!
Thanks & have fun! :)


I spoke with the tuner (mail order) and he is willing to work with the tune to getthe A/F right.

BUT I want it done right ASAP, so I will probably be having it tuned locally. My main concern is having it ready for DH10. I'll make sure to post the results.

[Z28pr0jekt]

Obviously a dynotune will pick up some power over even the best mail order tunes so that will be your best bet. But I know pcmforless always worked with me on retunes by using my datalogs and such and they didn't charge me for them unless I changed something on the setup.

[1FASTSS]

Have the car dyno tuned. Its the only true way to get it correct. I put down 391rwhp thru and A4/3.73/S60 so your numbers are low and it looks like its pig rich right now.

[ksmyss]

nice numbers you will deff be picking some up once the fueling and timing is played with.

were was the a/f reading taken? if its in the tailpipe then you are most likely even richer on the a/f seeing that they tend read on the lean side and are slower to react.

we tune and messure by one right after the header collectors

[AChotrod]

I also think it will pick up alot with a tune alone!! Good luck at DH10!!!! Love that combo your runnin!! :):)It will only get better!!