TRAXION

I dynoed my car. She started off at 339 rwhp. She ended up with 364 rwhp. I know she would have easily churned out 370 rwhp if I just had more time on the dyno. 339 -> 364 at the rear wheels with tuning ONLY the fuel. And I didn't even get a chance to FULLY nail down the fuel curve. I took my time and slowly leaned it out. I had the fuel curve setup really rich before the dyno to be on the safe side. I didn't even have a chance to get to the spark curves and the AFR was still way too rich over 6K.

FWIW - I am running 30lb SVO injectors at 45psi and my injector duty cycles were only in the neighborhood of 75%. Plenty of room for growth.

This is with a single 3" exhaust with a restrictive muffler, a hydraulic roller camshaft, a STOCK bottom end (motor has never been out of the car), and a 700R4 that has never been rebuilt. If this car were a manual it would be registering ~390rwhp (I'm running a 3600 stall and losing a lot through the driveline) so I'm pretty darn happy with these numbers. Not bad for a stock bottom end 350 and a stock tranny

Here's the curves. This is the first pull compared to my last pull. The dyno is reading 200rpm greater than what it should ...
http://www.celligent.com/tim/iroc/dyno/dyno.jpg

AFR comparison of first pull compared to the last pull ...
http://www.celligent.com/tim/iroc/dyno/dyno_afr.jpg

Video (4 meg) ...
http://www.celligent.com/tim/iroc/dyno/dyno.wmv

Tim

ski_dwn_it

NIce gains! Those ETs should drop with that kind of gain....

Can't beat those dynos to tune with. They are the only way to effectively/quickly realize gains.

Good job!

Grumpy

Just out of curiousty what injector size are you using in your calculations. And with the fuel tweaking now how does it line up with the commanded AFRs?.

It would now seem that for final tuning track side, you could just change the commanded PE AFR in the PE AFR to coolant temp table, and know right exactly you are, and where you should wind up, without guessing about what percent change in PE vs RPM will make what in actual AFR.

So you have known AFR, and known PW/DC, and now know room to grow. Congrats on knowing where your setup is.

You got any data logs from the runs?.
Doc and Sleepy wanna give em the once over.

Grumpy

Trouble is, dynos as a single source aren't always the best answer. On track performance, and reading plugs are always the final check. Dynos do leave room for error(s).

TRAXION

To which calculations are you referring (DC being indendent of inj. size)?

It's a little hard to say because the coolant temp and intake air temps also play a role and they are different from run to run.

I think that if the coolant and IAT weren't different between runs then this would be easy. But, given those factors ... and given how these would be different at the track (along with baro readings) it would make this rather difficult to do. As an example - my injector pulse width was HIGHER on my last run even though I leaned it out anywhere from 6-12% in the PE tables (this correlates to 12-24% when using WinBin and GMEPro because they scale it differently). I contribute this greater PW as a function of coolant temps that were almost 35d cooler and an intake air temp that was several degrees cooler. I think I'll just have to stick a wideband in the intermediate pipe at the track and take a look at the plugs.

Tim

ski_dwn_it

Who said anything about errors? And read exactly what I said. "quickly/effectively", you reading into things?

And how would you know about track performance? LOL You must have read that over on the GN board.

Can you ever leave what someone else says alone?

-------------------------------------

Trax your improvements on the dyno show what a little time on a good power measurement device can produce. The gains you got from the dyno could have taken months to realize at a track or road testing. Lets hope all that new found power is able to be utilized on the strip.

TRAXION

... lol ... do you mean "get to the strip before you blow up the stock motor and tranny"?

Tim

ski_dwn_it

LOL, No! Not at all, I mean hopefully you can put it to the road and realize the better ET/MPH. I know you are like me, trying to mustar the best ET/MPH you can out of your setup...sometime added power makes the hook harder to maintain etc.

How long have you had that combo together like that? Just curious? And I would also like to talk to you on the side with regards to your water pump you have. I saw pics etc of it on your site. That is a different topic so I don't want to dwell on it here. Let us know about what changes you have made, besides tuning to realize the gains, or was it all just tuning?

MikeH

iTrader: (10)

Nice numbers...The peaks improved but it looks like you lost some from 4000 down. That Miniram really has a nice topend charge.

TRAXION

In the 1/4 I am never below 4000rpms except during the first second at launch. I have a 3600 stall converter and when I shift at around 6500 the rpms drop down to greater than 4000 rpms. So - it really doesn't matter

Tim

TRAXION

This combo has only been together like this for about a couple months or so. By changes are you referring to the changes made between the two dyno runs shown in the JPG in the first post?

Tim

Grumpy

Probably not as much as you, LOL.

Ya, you have what 2 dyno pulls now, and how many passes?.

Grumpy

For the BPC or inj constant.

Was the 35d temp difference deliberate?.
FWIW, I have my PE AFR vs CT flat thur out the usable CT area. So if from 160 to 190, I'm at the same commanded AFR. As I gather more data then I'll skew it to better reflect the best performance. But, initially it gives me a way to begin to align the WB to commanded AFRs.

Grumpy

One other thought was if the second run was that much cooler did the restart values time out before the run?. Or was it start and spin her up, without timing things out. Dunno how many things are timed out in the 8D code, but in some cals there is a faira amount of time for them too.

87_TA

Nice numbers Tim,
I know many have asked ,but you have never answered what the car has run since the new list of mods?

Sound like you have made some nice gains,watch that you do nt lose any stall speed with that little torque loss.



I have been trying and trying to flatten PW at different
coolant temps ,and have made all numbers in the change vs coolant temp to same value..
but no matter what I do,PW is about 7% higher when coolant is below 140.
I also have changed all the values in the Openloop F/A adder vs coolant to same value.
But no matter what 7% richer below 140.
That is after about 2 mninutes of driving to my test area,so I would asume that all decay would be gone.

mike89z

Just wondering why you didnt run the filters? That doesnt affect the MAP readings at all? I was always under the impression that any change in the intake track affected MAP readings, but maybe Im just thinking idle and part throttle. Anyway nice numbers and one last question for ya, what RPM were the injectors seeing 75% duty cycle. Just curious cuz I have a few injector ?s.

TRAXION

87TA:
I haven't run the car yet with this new combo - that's why there aren't any new numbers. I might run it at the scheduled track event at the thirdgen nats.

Mike89z:
I ran without the airbox hooked up because the camaro airbox costs my setup about 5 rwhp. The filters are plenty big enough and I would have run them if the airbox wasn't costing 5 rwhp. So, my testing was done without the airbox. One day I'll build a custom 4" CAI but I need to move the battery to the trunk area first since that is where I want to mount the filter. You are correct on your thoughts about the MAP.

I indicated "in the neighborhood" of 75%. Actual value was 77% and was at 6400rpms. However, I was running rich at 6400rpms so that number should come down a percent or two.

Tim

primo

TRAXION,
What injector size did you program in your chip? I'm also running 30# SVOs.

poorboy8

I was under the impression that 11.5 is a good AFR? Last time I was at the dyno the guy was tuning for a 11.5 AFR?

JOOC what kind of O2 voltage were you reading (stock O2) before you made your changes on the dyno?

BTW, great numbers on that stock bottom end........crosses fingers

TRAXION

11.5 is too rich for a naturally aspirated engine. Sometimes they tune for 11.5 on a forced induction engine. I picked up significant power going up to 12.5. You want to shoot for around 12.7 ... but, let the numbers speak for themselves. Run an AFR that gives you the most power while still giving you a small safety margin.

I have 33# injector constant in my chip with a fuel pressure of 45-46psi.

Tim

tpi_roc

Out of curriosity how did your STOCK 02 compare with the WB?

TRAXION

HA! Not very much at ALL! The stock O2 mV was almost the same between the first and last run. In some cases I went from 11.5 to 12.5 and the O2 was the same.

Tim