What Do You Think?

[RPR33]

Hey guys just looking for some opinions here, this is my last dyno run, on stock turbo (as far as i know) high flow'd fuel pump, front mount cooler, and 3" turbo back exhaust. boost at 12 psi however it drops of to around 10psi.

I know guys running the same mods and making 30kw less. my ecu has a "ksp tunning factory" sticker on it, could that explain it? do you think the turbo may be flow'd?

also what do you think I should expect from a safc?

Cheers

Russ

Edited August 8, 2007 by RPR33

[R31Nismoid]

I would expect no increase in power really as you can tell the dyno is a bit high with the AFR's like that which should be hurting it a little.

The power reading isnt high enough to suggest a larger turbo, just a minorly *high* reading to me on a stock turbo with a Jap modded ECU.

The ECU you have is probably fiddled with, but it doesnt really help here in AUS with our fuel and conditions.

So around 190-20rwkw genuine with the AFR's in the 12s once you get the S-AFC on there.

Pretty much what everyone else makes really

You should feel the difference with the AFR's a bit better. It wont feel as "doughy" so to speak. Bit more zippy on boost.

[Adriano]

A cold air intake will help

[TTT]

^^^ how did you get that from his post or dyno graph?

[RRob]

Because his Intake temps are 18degrees above ambient temp.

Might see just over 200rwkw with the afr's cleaned up imo.

[Nismo_God]

dont really know what im talking about but i got basically the same mods except my ecu hasnt been played with....

my A/F slope downwards tho, start at 12 and then head downwards.....might be able to post dyno graph later....

made 205kw so not uncommon....

but my A/F is definitely diff to yours....

[RPR33]

I have had other dyno runs resulting in 218rwkw before. this is the lowest I have run on that boost (12psi) I put this one in because on that dyno on that day every else who run there car thought it was spot on... most people did get a little less then they had got on other dyno's. thats why I think it may be a flow'd turbo? with boost dropping to 10psi and a bad tune it's still making good power. I have mates running the same mods + safc and making the same power, however there boost will stay at 12psi, and there tune is alot better. and side by side I'd say my car has the power ot there's for sure!

also I have same what of a cold air intake. (boxed off pod)

Edited August 9, 2007 by RPR33

[R33silverS2]

Definately looks a bit wierd from my experiences on the dyno. I have basically the same mods but with an safc and made 195rwkw on 10.5psi. But your afr's plummet to 10.5 in the main power band area so to speak which doesn't seem to affect your power curve. No dips no nothin... Seems weird to me. When my afr's we dropping that low before the safc i only had like 170rwkw or so with a real unsteady curve... could your timing be real advanced or something with the jap tuned ecu?

[RPR33]

Yeh I think the timing would have been changed.. as you said it has a very good power curve and output considering the tune, thats why I think it must have something I don't know about??? any idea's guys???

[Adriano]

^^^ how did you get that from his post or dyno graph?

Take a look at the bottom of the graph, it shows ambient temp as 22 degrees, and inlet temps as 40 degrees

[R31Nismoid]

Take a look at the bottom of the graph, it shows ambient temp as 22 degrees, and inlet temps as 40 degrees

Because his Intake temps are 18degrees above ambient temp.

Might see just over 200rwkw with the afr's cleaned up imo.

Nah, thats because according to Dyno Dynamics handbook, the sensor must be placed in the engine bay.

Which IMO is stupid as it adds a correction factor, and then the I/C does the cooling job so the air is no longer at same temp as the corrections being applied.

Hence a higher reading generally speaking.

[RPR33]

do you think this would change the results by much?

[Adriano]

Nah, thats because according to Dyno Dynamics handbook, the sensor must be placed in the engine bay.

Which IMO is stupid as it adds a correction factor, and then the I/C does the cooling job so the air is no longer at same temp as the corrections being applied.

Hence a higher reading generally speaking.

I agree its stupid, i used to stick it in the airbox/pod, but i agree, it should use the ambient as the correction, and the IT just for dataloging. And yes, it makes quite a lot of correction, by moving the sensor you can lose or gain 20rwkw at these power levels, that would explain the slightly raised power.

[RPR33]

The senor was in front of the pod. so I have know idea why the temp is so high.

[BHDave]

The temp correction is good for around 10-12rwkw if you have a 20 degree difference in temp. The pod isn't far from the radiator so the IT will creep up over time if the sensor is left there for a few runs. Best to just put it in there right before commencing a run.

The other thing worth noting here is your aftermarket ecu isn't doing too bad a job IMHO. Your mixtures are a bit rich but they are stable, and i suspect that the ecu is probably a little more aggressive with the timing than stock (as most of these remaps are) which means despite the rich mixtures you probably have a fairly nice responsive engine, where as a stock ecu with similar mixtures will be a bit of a slug as it will lack the timing.

I really don't think you'll gain a lot with an safc, as if you start to take fuel out i suspect you will run into detonation issues pretty quickly, but, i'm making an educated guess, so don't take that as gospel.

[RPR33]

Why do you think I'll run into detonation issues? yeh I'd say the timing has been tuned up as It does drive very well! I hope I'll gain a little more power and at least get a little better fuel economy with a safc, as Its the worst skyline I've ever seen on fuel... I checked the fuel pressure today which I think is right at 40psi just switched on, and then upto 47psi once loaded up??

[TTT]

Nah, thats because according to Dyno Dynamics handbook, the sensor must be placed in the engine bay.

Which IMO is stupid as it adds a correction factor, and then the I/C does the cooling job so the air is no longer at same temp as the corrections being applied.

Hence a higher reading generally speaking.

Exactly..

so basically, if he had a CAI in this instance, it would have shown a lower amb reading and therefore would have had an even lower power output.

[RPR33]

I have a box over the pod with a hole right under it (stock intercooler pipe)

[BHDave]

Why do you think I'll run into detonation issues? yeh I'd say the timing has been tuned up as It does drive very well! I hope I'll gain a little more power and at least get a little better fuel economy with a safc, as Its the worst skyline I've ever seen on fuel... I checked the fuel pressure today which I think is right at 40psi just switched on, and then upto 47psi once loaded up??

It's due to the way an safc works. by bending the afm voltage the ecu sees, it figures you are at a lower load point than you really are, which mean 1) less fuel and 2) more timing. So setting up an safc is a balancing act between getting correct a/f ratios and avoiding pinging.

Your base fuel pressure is a bit high. You should have ~36psi base (2.5 bar) with the vacuum signal to the reg disconnected. Plus boost, minus vacuum

Your fuel economy is likely due to a dead or disconnected O2 sensor.

[RPR33]

yeh I have been told its not the o2 sensor,(in saying that I don't know if they have ever checked it). as soon as the car got bad on fuel that was my first thought but the machanics keep saying its just the computer... I guess it's just an easy way out without doing anything.

I had about 40 and then 47 with the vaccum to the reg disconnected??