recsate

OK Finally got dynoed today. I definetly need a tune. The results were really weird. It seems that the timing is being pulled back or something. There was a pronounced lean condition that appeared around 4K and then a few rich spikes around 6.5 to 7.5. HP and Torque was all over the place from 6K up.


Anyone experienced this in their adventures. I am going to have it dyno tuned in a week and a half. Anyone have a map that might be a better starting point to tune with?

trying to attach dyno chart but I am having troubles..

Lschiavo

try posting your picture bigger so when can open it please

recsate

see edited original post

recsate

Here is the data file I got from the Dyno. Pretty good data but for some reason the data stops around 5750 RPM's. I think there pickup for the tach was on the fritz or something..

Lschiavo

That happened to me too. What i think is that since the throttle in our cars are controlled electronically they kind of lift at the end. You can see how it becomes rich inmediately, it is because the computer is lifting the throttle and that is why u get those spikes and no more Hp. I would think based on the numbers i saw that your car is making around 235-240..

My car stopped at 195 and i got those spikes.. here is a pic of mine (look how it becomes rich when i get the spikes)
Of course it does it on the dyno, not on the streets. Look at 5K RPM we both are at +- 190 HP. That means both turbos are consistent.

swoope

iTrader: (5)

this is kinda stupid, but it happend to me. how much gas was in the tank?????

i was out making some runs with less than a 1/4 tank and the throttle kept pulling back. this engine managment system is smart.

beers

Lschiavo

Now that u mention it, I remember i had like 1/8 of fuel tank. Very low almost in yellow light. That might have been the problem. Lets wait for him to tell us the same so the theory is confirmed. (lost $120 like an idiot)

swoope

iTrader: (5)

yea,
it was weird when it happened, just shifted int 5th. and the car just slowed down with throttle wfo.

filled tank up and 20 mins later hit top speed that i have done in the car. no problems.

beers

epitrochoid

yeah, there is a system that limits speed on low fuel in the higher gears.

kinda scary the first time you're doing 120mph and the cars suddenly falls on its face.

recsate

I had about 1/2 tank when on the dyno.

rkostolni

I believe something screwy is happening at my higher rpm's as well. It seems all the newer Greddy kits are having some kind of issue with the tuning at high rpms. The early kits never had this problem. Maybe Greddy changed something in the maps. Someone with a dyno chart should email them and let them know that several people are having problems like this, see what they have to say.

smrx8

iTrader: (1)

what gear did you dyno at ???

recsate

Did the pull in 4th gear

dgerald

I'm feelin' you bro

Richard Paul

iTrader: (5)

Your mixtures are OK. Look in the upper right hand corner of your printout. You will see a smoothing number, this rounds off the spikes. It should be set at 5 not 0.
You can call the dyno shop and if they still have it in memory they can redo it with a 5 smoothing number. I think you will see most of those wiggly spikes go away.
Post the new printout and lets see how you look.

You have to get to the same sort of correction as everyone else. They all use SAE, smoothing 5. Also it would be nice to know the temp and humidity. You'll have to write it down or ask for the other sheet of numbers.


Luis, I can't see a smoothing number on your sheet. Nor what correction they used. Both of these show the effect of the pulling of man pressure at the top end. It flatens out. All in all these don't look bad for a street engine. You have a lot of mid range to work with and I bet it is a lot better driving around town. Less down shifting to pass or just speed up. These are not built to be race car type turbos. I think they did a respectable job. There are still some tuning problems but they will get solved. The only long range questions are how everything will be effected by the heat. Things will fail, but when? They may live long enough to be acceptable.