Dyno Run After Tune..little Bit Disapointed

[The Mafia]

hey guys, I'm the one that did the tune.

We've left it pretty rough for now as the dyno run was only a power run, not a tuning run. I agree, there is a bit more tuning that needs to be done (In my opinion the curve is bad, and needs to be more straight, but nothing I can't handle). Its only been on the road twice for a couple of hours each so I didn't expect the AFR line to be too straight, but straight enough.

We gave up early because I did the usual tuning "tests" to see if there is a restriction.

1. Boost from 18psi to 20psi - 272rwkw to 278rwkw - Shitty gain

2. Timing - Increased timing on full load by 2 degrees - Power up to 281rwkw. Shitty gain.

3. More timing - No more gains AT ALL. Eventually, detonation

This leads us to believe that there is something stopping that extra power being made. You could feel it restricting somehow. Everything else is great though, torque curve is nice and straight, and consistant, power curve is about what you would expect with a 0.82 rear housing.

I'm making 314rwkw with the 0.63 rear, and most the the same, other gear. Here are the only differences (as per my 314rwkw run)

- Intercooler piping is bigger from the turbo to the hot side of the intercooler

- 0.63 Rear housing

- 225ml\min water meth nozzle (Mitch is running a 375ml)

- Larger q45 AFM

- Standard Intake Manifold

My car had the horrid 2.5inch cat on it when I did that big run.

I will say this though - My car has always felt a little laggy off boost. Nothing bad, just different from most other R33's that I have ridden in. This makes me think I may have cams installed. I do not know though. I'm getting that dreaded Exhaust side tappet cover leak fixed soon, so I might check then and see if the cams are any different to stock.

I'm sure we'll find what is wrong. Just a matter of trial and error.

Here is my cars dyno print out (same dyno) with a new fuel pump and a quick 1 hour road tune done all by myself and no driver.. (annyoing! haha)

Edited March 10, 2009 by The Mafia

[SS#eater]

trial error and head aches lol

cant complain really..i guess there is alot of people on here wishing they could make anything close to 280kw but i just got to crack that 300 mark....

[craked]

i run a different setup but i use a greddy copy and make 500kw with no problem it is a bit lagger then the standard one but i did picked up about 20kw. fix the exhaust its a problem i had a 3 inch exhaust with a 3 inch gudded cat and the cat housing was the problem i changed to a full 3 1/2 inch exhaust and what different it made to the boost response it was like a new car. the cooler pipes, i have been there and done it didnt pick up any more power but i did pick up 200lb of tourqe. thats just my results from what i have done. good luck

[The Mafia]

thanks for the suggestions craked

[Fastrotor]

Cmon Mafia, i though you'd have a spare boost gauge lying around..... just make up an adaptor for the O2 port and measure the Backpressure. Good tool to have in the tuning arsenal.

Gary

[The Mafia]

actually, I have never really thought of that..

I will see if i can make something up.

How do you go with the heat though?

[Tangles]

281kw seems pretty ok to me

a little sorting out, and you'll crack the big3-oh

[Fastrotor]

No probs, just use a silicon hose or something abit higher temp ..... its only in there for a couple of pulls , or runs on the street. Just give it abit of length to keep the heat from the gauge.

Been doing this for years, easy to catch dying cats with. Just did my own skyline recently, suspected dying metal cat, sure enough 7psi ! .. gutted it to get 3.2psi !

Just hook it up to a second map channel on the dyno and you can graph it along with the power curve.

Gary

[SS#eater]

fastrotor

thats a great idea.....will definetly look intot that.

mafia i got an old boost gauge i think and i can pull the middle out of an old o2 sensor and weld a fitting onto it to run a bit of heat proof hose to the gauge

[Fastrotor]

No Probs, hope you find your problem. I know what its like, im going thru the same thing with mine !

Gary

[The Mafia]

haha I am glad that you are handy with a welder Mitch!

[SLAPS]

I will say this though - My car has always felt a little laggy off boost. Nothing bad, just different from most other R33's that I have ridden in. This makes me think I may have cams installed. I do not know though

Would be nice if cams were installed but I tend to doubt it as its near impossible to notice the loss of power down low until the cars noticeably caming over.

Chances are either cam timing is slightly off OR most likely its running a thicker headgasket or the motors running a lower static comp due to being previously rebuilt.

IMO

[SS#eater]

this is going to be interesting....

ok this is a stab in the dark...what if my cam timing was out by i tooth... could this be a possibility or would that show itself before the tune

[SS#eater]

hey thought i might post up the results of the back pressure test with the boost gauge on the dump pipe...

i have 5-6 psi back pressure..it really suprised me how much! will post the result after i fix the restricting cat......

[Fastrotor]

waiting with baited breath....... Hope YOU get some results....

my personal car was 7psi ! , gutted the magic cat, and dropped to 3.2psi ..... gain ? NOTHING. Hence why im still scratching my head....... Just plumbed in a 100psi stainless sensor via silicon to the turbo manifold to measure TIP..... Would know by now but unfortunately in my rush to change oil filter, i broke off the oil filter mount thread !!!!!!! Arrrggg....

Gary

[Haines]

What size thread is it gary ??

I have a spare one at home here I think its 19mm

you can try it if you want

[SS#eater]

hi fastrotor so you had no gains....dam...did you dyno it to check results or could you notice no gains driving around...i guess untill you have 0 back pressure still going to be a problem

[Haines]

I have the same sort of thing happening with mine

boost increases do nothing

14psi seems to be the sweet spot anything above that doesnt give you much more power

although i did find a big boost leak in mine which ive since fixed but havent run it on the dyno since.

the car feels different to drive so im hoping it makes a big difference

[SS#eater]

yeah its suxs....

i got a list of maybes to cross off

exhaust is 1st

bov leak 2nd

boost leak else where.

doing exhaust today then dyno run it see what changes....

[Haines]

what heat range plugs are you running ??