Thread: Going to the dyno this weekend looking for advice (results posted)

Hey guys,

well I ended up winning a free hour at a local dyno shop on their dyno dynamics. It wasn't my plan but it happened so next weekend I am going in.

I finally bought a new laptop because up till now I never had one.

I am fairly fluent with the software portion of the tuning and that I have done on the street and all with my wideband.

The part I am asking for help with is that I have no idea of the best most efficient way to actually tune the car on the dyno.

I have heard/read about two ways to tune. The easy way, would be to just do a few pulls, map trace, and continue to do pull after pull from 2k to 8k. Hone in the a/f then fiddle with timing, bumping it up until power drops off then backing it down a degree or two. Making small adjustments and then making the pull to see how it affected power.

The second way, since the dyno dynamics is loaded, is to hold the motor at a specific rpm, and tune the cells adjacent and including the one being utilized for each 500rpm or so until you have completed from lower rpms to redline. That scares the **** out of me because I have tuned that way on our engine dyno at school and coolant and oil temps go up extremely fast tuning that way. Granted that was with 500hp Chevy v8's.

I am going to be nervous, anxious and only will have one hour. Can any of you guys who are experienced tuning your own vehicle or others on a dyno offer me some advice so I can go in there as prepared as possible?

I realize the general BS...have everything ready, charge my laptop, cover all the basics, spark plugs, oil, coolant etc... i don't need to hear any of that.

I guess what will give me the best results with one hour? I don't want to bite off more then I can chew.

Thanks so much.

Dudeman

Btw, in case anyone cares, this is the same dyno I was at about a month back.

I made 167.1whp @7750rpm and 117.0wtq @7300rpm with the following mods:

sr20ve
N1 cams
3inch header back
Charles 4-2-1 Budget header
wai
n60maf
JWT pop charger
9lb flywheel
no a/c
calum realtime
running a hybrid tune I made myself
n1 water pump

While that was lower then my first dyno two years ago before the header, intake, n60maf, a different tune etc...the car feels faster then it did back then (173whp).


Dudeman

sounds cool man,is it a shop in charlotte,im going to the dyno soon too.i book a dynotune with rlz engineering march 5th,getting car tuned with nistune rt...

Your tq seems low.

Was a correction factor used on the Dyno Dynamics?
If not, then 167whp/117wtq might not be bad.
They read significantly lower than most dynos.
When I dyno'd on one here, they used a dynojet correction factor.

Using the loaded features of the DD can take a lot of time.
1 hour will go by quickly. I'd stick to your first plan, but ask the
shop what they recommend, and if they will help you tune.

You'll probably want to play with the cam switchover point also.

Thanks allot jp, good to have an opinion. I guess I will just do it that way, don't see a reason it won't work fairly well to hone in my timing after the af is looking better.

Although my torque might seem low this thread was created for those with tuning experience to give me advice about tuning. I have other threads dedicated to my epically low and consistent dyno numbers feel free to peruse them at your leisure.

I will post up here with my results and see how much improvement I can make.

I heard the ve is fairly safe to tune without knock detection, hopefully there is truth in that. I plan to go till power starts to drop then back off.

Dudeman

Agreed.

Hey man! Yeah it is local, SixSigma, they aren't the best but a free hour is a free hour!

I have a few friends who have had their cars tuned at rlz, maybe if its ok with you I will drop in on the 5th and check your car out?

I cannot wait to see how it goes this weekend.

Dudeman

Here's what I would do, if I had an hour (which in all reality will probably be about 40mins since we have to tie the car down, etc. etc.)

If your car still has closed loop fuel control, I would just focus on the WOT tuning, since you have probably spent some time with the partial throttle tuning on the street.
- Make a few pulls to establish a baseline.
- Watch the AFR curve to see if its where you want it, get that dialed in
- Set the Cam switch over point to a low RPM make a pull
- Set the Cam switch over point to a high RPM make a pull
- Set the Cam switch over point to RPM where the TQ lines of the two previous graphs cross

With those items complete, then I would mess with Ignition timing.
- Add 2 deg at a time to see what makes power, and where (RPM)
- I would venture to guess that a NA SR20 with good fuel is not knock limited, meaning that the motor will stop making power before it begins to knock.

Don't be anxious, or nervous, I'll be in the car to help you out and answer questions if you have them. My thing is, don't be afraid to ask if you're concerned about something. There are no stupid questions.

-John

thats fine man drop by,i hope howard can get the hang tuning it quick,no dogging howard or nothing but he says he hasn't really messed with the nistune software he has...then again he a great tuner so it should be real easy for him