Poor Dyno results, car is sluggish

[S8ER01Z]

Any thoughts? This was done on a dynojet 224x 4th gear pull.

AFR on the first pull was bad so there was a quick adjustment made in HPTuners but it didn't help power at all.



Numbers were 324.92rwhp 343.31rwtrq, AFR (redline) was roughly 13.5-14.0... I have a log that was taken during the dyno (provided below). I fear something is wrong with the car...fuel pressure appears to be solid at almost 60 idle and barely dipping to 57-58 at WOT.

HPTuners recording from the dyno pull above.
https://www.dropbox.com/s/wsn2o75dzq...o%202-8-14.hpl

Edit: Removed Tune/config... using a different file now.

This tune is a cluster and I know that..just looking to sort this out. Wideband will be on the car sometime in the near future but I'm just looking for ideas to look at before I get that far.

Thanks!

[mowton]

Did you have the Dyno O2 in the tailpipe? Found it in the above dyno sheet...disaster producing lean!!!!! At 4800 RPM you injector pulsewidth actually begins to drop???? Stock, a PE tune and some timing? What is your plan? Be careful.

Ed M

[S8ER01Z]

I have a real tuner who is going to work with me... I just fear there is something mechanical that I have overlooked but nothing stands out to me. It had a tail pipe sensor and the AFR the first time was scary... Just hoping it holds together long enough to get it sorted out.

[mowton]

I would make sure your Fuel pressure (58 psi) is holding at WOT and your injectors are clean for starters. But again, the tune seems to be reducing the injector pulsewidth so look at tuning the MAF. Put the PE back to command 12.8 AFR or 1.15 and sneakup on the higher RPMs with an O2.

Ed M

[DSteck]

When it comes time to do it right, put the sensor in a bung. Tailpipe readings are not reliable.

What's the setup?

[S8ER01Z]

Sorry completely forgot I don't have a signature here.

2001 Z28, freshly rebuilt l33 (Thompson Motorsports shortblock 5.7L spec).
Ls6 cam
241 heads
Ls6 intake
Ls7 lifters
7.42 hardened pushrods
1 3/4 BBK longtubes (no cats)
MTI Lid/Free ram air
Racetronix fuel pump
Stock 28lb injectors

That's the relevant mods.. Some other odds and ends that I don't think matter like melling oil pump, ls2 timing chain, etc

[DSteck]

I'd expect more like 360-380 from that. If I get to a computer and think of it, I'll look at the tune.

[mowton]

I'd expect more like 360-380 from that. If I get to a computer and think of it, I'll look at the tune.

Mostly stock, PE at 1.4 some torque management and Cags......

Ed M

[S8ER01Z]

Thanks for the info guys. Should be meeting with tuner this week (another 6 inches of snow on the way so wont be early this week as I had thought). Hopefully it is just the tune and a good tune fixes my issues. Power dropped off way early which is why I thought maybe something was mechanically wrong. Guess we will see.

[THE CHAD]

sorry Dsteck don't agree with you about power figure mate.....sorry not with a ls6 cam, very small lobes... over here that would make approx 325-330rwhp( is it a manual or auto) on a true dyno mate , I tuned car the other week with a DECENT size cam etc 236* which is a baby/moderate cam that with all the bolt-ons made 364rwhp and that is a lot bigger stick than an ls6 cam just my opinion mate...by the look of it that is a tad too lean 12.9/13.0 should be the ball park figure on that setup but it depends on the tuner also, every combo is different.. some tune rich(safe) or some on the RAGGERED edge(lean) and what sort of timing is it running...PE at 1.4 ? mmm...you could try to put say PE like this for a example of 12.94 afr at 14.62587 stoich.......PE at this etc 0rpm=1.000 400rpm=1.000 800rpm=1.010 1200rpm=1.020 1600rpm=1.080 2000rpm=1.100 2400rpm=1.120 2800rpm-7200rpm=1.130 try that dude..... but remember only tune in LAMBDA..... if in LAMBDA it would be, approx. 0.88-.0.89

[DSteck]

Bolt on LS1s make mid 300s.

[LSxpwrdZ]

Depends on dynos. This setup being on a dynojet it "should" easily make 360ish or so. My bone stock '00 LS1 Camaro made 303rwhp dynojet back in 2004-2005.

Now on a Dyno Dynamics like mine probably 330's at best only because I've had some bolt on C5Z cars make 330's as reference.

[DSteck]

Depends on dynos. This setup being on a dynojet it "should" easily make 360ish or so. My bone stock '00 LS1 Camaro made 303rwhp dynojet back in 2004-2005.

Now on a Dyno Dynamics like mine probably 330's at best only because I've had some bolt on C5Z cars make 330's as reference.

OP was on a DJ.

In Illinois I might add.

[THE CHAD]

yep depends on dyno.....Mainline dyno's are very good too/as are dyno dynamics...operators are different too, strapping down also is a major difference in power readings and as you guys know the temp probe also plays a part.....when I tune I ask operator not to use the probe.....the average bolt-on ls1's I have seen average from 272rwhp up to 348rwhp (manual made that bit of freak )....350rwhp I saw but not strapped down correctly and temp probe was used in wrong manner ie AT=26*c IT=57*c which also blew the reading out...there will always be THIS DYNO CHAT ABOUT POWER ....but also boys TORQUE win races too......same car same dyno/different operator =272rwhp(202.83rwkw) and then get this different operator 301rwhp(224.46rwkw) on the same dyno same conditions same day,, you tell me whats wrong.....and explain to the customer that there is nothing wrong with his/her car.......which what can happen is he/she will go to the one that produces the higher figure and then tell their friends that their 360-380rwhp cam only ls1's aren't that crash hot and then they go to that dyno that reads higher and bang more work for that dyno/operator....then they go to the drags and only run 12.70 etc and the 360-380rwhp ones run 11.50.....AS I ALWAYS SAY ALL THE TIME THE BLACK TOP DOES NOT LIE AND EITHER DOES THE MPH.....MPH= RWHP, just my thoughts....I may upset some people on this topic but I tell the truth and see it as is.....My opinion every tuner/dyno operator should for atleast 30mins spend time explaining to the customer about how a dyno can read different if the correct procedures aren't used, ie one click on the tie-down straps/wheel chocks/ the way the car comes up on the rollers is a good one......one example(tuned by someone else) a mates car a vz ss thunder ute 6ltr L76 6spd on the dyno it read 400rwhp and by rights that car SHOULD run 11's all day long at 119-121mph set up good and then it only ran 13.40/107mph you tell me that is making 400rwhp and it didn't wheelspin cause if it did and it made 400rwhp that mph would be higher.......so now after talking to myself and how I explained how different dyno procedures affect power readings I said to him I will tune it/sort it out and if It doesn't run 11's/and drive better I will give him his money back.......LH torana LQ9 block 408stroker big cam 250* on one dyno it made 454rwhp and then on the dyno that I know made 389rwhp......one other ls3 long tube headers 4into 1 twin 3'' and .otr mafless tune 370rwhp

[S8ER01Z]

I would be willing to buy the numbers of the peak power wasn't off the mark by a lot (peak power happened at a much lower rpm than expected), mph at the track just isn't there and it wasn't a Dynojet 224x (which should make higher numbers than the "low reading" dynos which apply loads for proper tuning).

I'm not chasing a super high number here, it's pretty obvious something is wrong here I just wanted to see if it was anything obvious that might not be corrected with tuning.

Thanks guys.

[THE CHAD]

S8ERO1Z, mate if you are a bit worried about your motor due to the LEAN running at W.O.T do a visual check/oil/cap/coolant etc if no worry signs are there, pull one spark plug out at a time and do a compression test on each cylinder mate and that will tell you the health of your motor/ which cylinder if any is damaged etc....when running LEAN mate it cause all sorts of damage , that's just my way of diagnosing a motor if worried mate, gd luck with it and I hope no damage has occurred mate cheers BRET

[VodeAn]

Power depends on altitude too.

My guess would be about 350-370whp on a sea level, on a good tune. Get your AFR taken care of and then maybe do a compression check.

[S8ER01Z]

True... Actual elevation here is 640ft and DA that day was -2888ft. 12F and snowing. Thankfully the shop was warm that morning. . I should have more this week if the weather holds.

[S8ER01Z]

Update: PLX Wideband installed. I put the stock tune back in and I'm seeing 12.1-12.5 at WOT... It appears to start near 12.7 and goes to 12.1 as the RPMs climb. Starting to warm up here (just snowed a few days ago so not warm enough) so I should get some time to make adjustments and hit the Dyno again.

Unless the plx device is somehow off it appears that the dynos sniffer wasn't right or that other tune was really really bad.

I'll update again when I know more.

[S8ER01Z]

PLX wideband pulls... Not sure if this is useful but if someone could take a look. Is any data other than 4th gear WOT useful? It's much easier to get data for the lower gears around here.

https://dl.dropbox.com/s/97kku68l90xjxdj/PLX.cfg
https://dl.dropbox.com/s/m4iwbbezw7j...lxwideband.hpl