My First Dyno, The Bad, The Good. (dyno sheet, video)

[turbogate]

My first Dyno ever since owning a car was this past Wednesday night. It was really just a few run to see where I stood, and what potential my set-up had. As you will see, my A/F ratio was all over the place. I lost my steady low 11.* A/Fs ever since I installed my VPC and never really had the time to fine tune it. The dyno sheet will give you an idea of the crappy tuning. That was at 19psi on a T04 turbo. (see sig for mods list) with 98 octane fuel from the local race track.

Engine has been pretty much tired, it has been 6-7 years of abuse without a rebuilt, and she also has been suffering from the Rod-knock syndrome, but has survived it so far for more than 5 years (one of these freak engine stories). I have a spare engine that will be getting the full works once that one finally dies. Anyways, the numbers

The bad first:
My best number of the night was only 367rwhp and 392ft/lbs of torque :icon_sad:

The Good (I hope you guys see it that way) the car never made it past +- 4800rpm because of fuel cut. Just when the turbo was starting to wake up. I didn't have the luxury of time either to try to tune past fuel cut as it was getting late. For 6 runs at a good price, I couldn't complain.

the very near future: I am officially done with piggy backs, I'm getting my AEM this month JUST to get rid of fuel cut, lol (j/k)



Heres the dyno sheet, and just for kicks a small video of the run.

http://i135.photobucket.com/albums/q127/turbogate/resized-DYNOJET_REV.jpg
Video: http://www.youtube.com/watch?v=fziuPOwqBmM

[MRSUPRA]

Wow, you got some major problems their. Looking at how laggy that dyno plot is, I would say you have a massive boost or vacuum leak. Which is probably why you are hitting fuel cut so early. Not sure, but something is wrong, and I dought it's the piggybacks. Good luck figuring it out.

[Nick M]

Perhaps you should ask Dr Jonez about tuning the VPC in the piggyback section.

[SevenMKIII]

I thought running speed density (i.e. the VPC) it eliminated fuel cut.

[turbogate]

I hear you guys, but i'm not even going to bother with tuning the piggy backs, my plans was to get the stand-alone this month anyways. that was just a couple of fun runs to see where I was. I'm going to double check for leaks though. i found that the wastegate lines from the Boost controller might have gotten to close to the wastegate dump pipe and have melter a little bit. I will double check this weekend. As far as the lag, it's very very rich at the rpms where it would start to spool, so that might not of helped much with the lag. Thats a .68 exhaust housing, so it's been laggy since day1.

[turbogate]

I thought running speed density (i.e. the VPC) it eliminated fuel cut.

It raises it much higher, but you will still hit FCO at a certain point, especially with a bad tune like mines with a bigger turbo. With a CT-26, it will be hard to get to that point because of the amount of air the stock turbo moves. Have I had more time, I would of tuned around FCO, but it was just suppose to be a couple of quick runs with minor S-AFC adjusments.

[empera]

heh reminds me of my dyno run...i hit fuel cut with vpc @ ~5k, reason was the wastegate not opening. VPC wont be able to tune much anyway, you'd need an safc or something to do so. vpc will practically just get rid of the afm.
my exhaust housing is also similar to yours.

[Nick M]

He could just have an intake leak. He is awfully rich, as noted. If that air is leaking out, isntead of finding its way to the combustion chamber, he will be rich like that, and hit fuel cut easier. But I am no expert on piggybacks, I can just comment on the way it is supposed to work from Toyota.

[turbogate]

heh reminds me of my dyno run...i hit fuel cut with vpc @ ~5k, reason was the wastegate not opening. VPC wont be able to tune much anyway, you'd need an safc or something to do so. vpc will practically just get rid of the afm.
my exhaust housing is also similar to yours.

I do have an S-AFC (see sig) Before I slap the AEM, I'm going to double check for any leaks etc that might cause probs for my real upcomming dyno tuning session.

[MKIIINA]

interesting... i run 18-20 psi on my JT61 turbo and vpc w/o issue. IIRC FC on a VPC is somewhere around 2bar + I think you have some other issues to work out. Overall nice numbers and check for some boost leaks. I'd say stick with the VPC if you arent going over 450-500 rwhp and get the car tuned correctly then see about the fc. Whats your Fuel pressure set at btw?

[turbogate]

interesting... i run 18-20 psi on my JT61 turbo and vpc w/o issue. IIRC FC on a VPC is somewhere around 2bar + I think you have some other issues to work out. Overall nice numbers and check for some boost leaks. I'd say stick with the VPC if you arent going over 450-500 rwhp and get the car tuned correctly then see about the fc. Whats your Fuel pressure set at btw?
My fuel pressure is at about +-43psi vacuum disconnected. I'm sure I could have figured out the problem if I had more time. The FCO started recently, and it also only started leaning a lot toward the top end recently which leads me to believe I have a leak somewhere. I will play with it this weekend to see what I find. I'm just impressed it would put down those numbers in that state of tune. after all thats +-422 flywheel hp at a conservative 15% powertrain loss at only 4800rpm. I have big goals for that car, and If I don't buy the AEM this month, I may not buy it anytime soon(getting some extra $$). In the mean time I hope to re-tune my set-up and find out why its hitting FCO and leaning that much on top while in the lower rpms it's ridiculously rich. Eventhough for now my goal is in the 450-500 with the stock engine, I want to have the piece of mind that when I'm stepping on it, I dont have to worry about a stock ECU pulling/adding too much timing with those piggy backs etc.

[daneyan]

i hate hearing people talk about lag so much. we have 3.0L and 2.5L motors in our cars and some 2.0, there's gonna be lag with any upgraded t4 turbo or sometimes even t3. only cars u don't really see lag on are those freakin 5.7L V8 etc.

[Supraboostin]

is that @ fynetune?? that car sounds mean as fuck,what exhaust are you running?

[turbogate]

is that @ fynetune?? that car sounds mean as fuck,what exhaust are you running?

Yep, that was at fynetune. It's 2 blocks away from my friends shop. I'm running a basic 3" turbo back pipe with a Megan N1 type muffler. I credit my cars' sound to the ebay turbular manifold and the wastegate dump pipe:icon_bigg

[MRSUPRA]

"i hate hearing people talk about lag so much. we have 3.0L and 2.5L motors in our cars and some 2.0, there's gonna be lag with any upgraded t4 turbo or sometimes little t3. only cars u don't really see lag on are those freakin 5.7L V8 etc."

The ability to interpret a dyno graph helps us understand that this car has issues. That dyno graph shows lag that has nothing to do with the size of the engine or turbo he is using. A To4 with that size turbine housing will not have that kind of lag on a 3.0 motor..Not even close..
Most likely there is a boost leak, vacuum leak, or wastegate/manifold problem.

[dbsupra90]

i dunno, doesnt seem far off to me.

here is a car i tuned a while back with almost identical setup. this was 14psi.
note the blue lines was first tune, and was hitting fuel cut.
red lines was near the end when making it all the way to redline.

http://www.mk3.us/dave/dyno/chrisdyno_lowboost.JPG