Low dyno reading???

[WATDA]

Hey guys, newbie here from New Zealand. Just had my car dynoed today. Its a S15 spec R and have some questions about it to see if anyone else has experienced them on there stock ecu's. My mods are turbo back exhust, apexi pod, 60mm throttle body and a electronic boost controller. Dynoed the car today and it managed 157.8kw@4800rpm. I thought this was a ok figure but ive been looking at the graph and comparing it with others and it seems my top end has major issues. It more or less got peak power at 4800rpm and went downhill from there. My dyno sheet only reads to 6500rpm as it was dropping off and no point going to redline. AF ratios go pig rich at the same time as the power dropping. Is this what most stock ecu's will do or would I have a faulty sensor somewhere which is putting it into limp mode or something. Will be getting a daughterboard and chip very soon and remapping it to get rid of the detonation coming on boost and the top end and it should be good for 180ish kw.
This is a awesome looking forum and will be looking around alot more
Andrew

 

[ichi-go]

Your AFR look very lean. You might wanna tune down the boost as you're leaning out in the top end. Stock pump doesnt like 1bar of boost. Since you're rechipping, get a fuel pump and you'll see some reasonable numbers.

 

[Nicely]

Is your cat still on? That'll cause some serious power loss around where you have.

 

[WATDA]

Ive got a Walbro fuel pump in there. Have turned boost down until i remap it. Its not lean up top its real rich? bout 10:5 ratios. I think it may have gone into knock maps up top since the power has dropped right off. Cat has been removed. Needs a bit of ecu work coming on boost as it was detonating. Just wondering if anyone else has had issues with stock ecu up top. That sheet is only reading to 6500rpm and you can see power was on the down hill bigtime haha.
Andrew

 

[eron]

My friend's car has full exhaust + pod, and boost restricter removed and made 170+ rwkw.

 

[ichi-go]

Real sober last nite and misread the graphs. lol

Yeh ur running pretty rich. Pretty weird that your power starts to drop but boost remains stable.

 

[evade]

I combined my psi/afr graphs so you can compare if you like.

I'm running stainless dump, hiflow cat, trust pe2 exhaust. standard bov is blocked and restrictor removed.

 

[j@garagemac]

what induction kit do you have as that part of the graph usually points to an airflow problem i.e not enough ??

kind rergards j@wrc

 

[WATDA]

I just checked my fault codes and have none so at a guess im thinking the factory ecu is not liking the mods and extra boost and has gone onto knock maps? The richening AF ratio on the curve matches exactly the drop in power and torque. Looking at evades plot it looks like max power should be made around the 150km/h road speed. Mine was on the downhill way before then haha. Power was looking strong until that point. Was just wondering if anyone else has had issues like this with the ecu but it doesnt look like it

 

[WATDA]

what induction kit do you have as that part of the graph usually points to an airflow problem i.e not enough ??

kind rergards j@wrc

Its running a Apexi power intake with stock afm intake pipe etc. Was just thinking, unplugging and removing the factory boost solinoid wouldnt upset the ecu would it?

 

[ichi-go]

WATDA,

Heaps of my friend is using aftermarket ebc and has no issues what so ever so that shouldn't be your problem. Only possibility of the ecu running so rich is faulty sensor? I believe if your water temp sensor is faulty, the ecu will assume the engine is still cold and run very rich but since there's no fault codes that rules it out. Keep us posted on how you solved it

 

[Nicely]

They is a huge lean patch mid-range in the standard JDM Spec R ECUs... Whether this is the case with NZDM and ADM SR20DET S15s, I don't know, but wouldn't be surprised.

This is the reason its not recommended to up boost on JDM S15s without a remap for lower RON fuel... During my first remap, and running 97/98RON fuel, mine was found to hit det a little above 0.8 bar...

 

[WATDA]

They is a huge lean patch mid-range in the standard JDM Spec R ECUs... Whether this is the case with NZDM and ADM SR20DET S15s, I don't know, but wouldn't be surprised.

This is the reason its not recommended to up boost on JDM S15s without a remap for lower RON fuel... During my first remap, and running 97/98RON fuel, mine was found to hit det a little above 0.8 bar...

NZ new ones are just JDM silvias rebadged There is a very lean bit on the 14psi run with also a bit of detonation but it still kept making power until that 125km/h mark. So by the sounds of it, its gone into knock map? As soon as the daughterboard arrives some tuning will begin

 

[Nicely]

Any det is bad news. Take a look at a few photos of the insides of SR20DETs which have gone bang from det...