Please Help Me Diagnose My Dyno Chart

[blackprincegts]

hey...

I had my GTS r32 dynoed about 1 1/2 years ago, mods were a 2 1/4inch exhaust and a k&n pod (which is actually on an adapter thats about 1 -2mm smaller that the afm opening) with no cold air induction..

Heres my dyno chart, i had lost it for quite some time but found it the other day and started to have a really good look at it.

rb20de dyno

As you can probably tell by the speed it would have been done in 3rd gear which isnt right i know but...

I noticed that my peak power was reached at about 5700-5800rpm, the power then seems to drop off significantly after this, thats what i find quite odd. This engine stock should be producing its peak power at 6100or something like that but by the time iv reached those revs the powers already dropping off quite quickly.

Is there anything that anyone can suggest that could be going wrong there to make the engine stop producing power where it does?? Is it possible that the dyno reading was setup wrong therefore meaning that the speed shown on the graph does not match that of the revs that i have plotted on there?.

Its hard to say for sure but when the car was new to me it used to come on power at about 5000rpm and pretty much maintain that pull right through to about 6500 and only slightly drop off by the time i would shift at 7000rpm. Now the car seems to all ova sudden go quite hard as soon as i huit about 5grand but die off again quite drammatically after this point.

In a way im kind of hopeing theres something only simple wrong so meaning that when fixed the motor should continue to make more power right up untill atleast where it makes it stock from the factory.Im wondering if it is my pod setup though thats sent things a bit wierd.. i should really do it properly and mount it down in the front bar and use the right adapter for it..i know people that have gained about 2.5 to 3kw's at the wheels by doing this..( a neck breaking difference i know, LOL )

Any input appreciated... cheers!

[Eug]

have your AFRs cleaned up, it won't entirely solve your problem - but it is a little over the shop. do you have an SAFC, ecu, chip or anything?

as to your power issue, the graph looks fine to me - but you've had history with the car, so just start troubleshooting. have a fiddle with your pod filter, service the car, look into timing advance/retard, etc.

that said - the dyno always feels/drives differently to when your actually on the street, so don't take it as gospel. does it "feel" slower to you?

[Cubes]

Whats the condition of your cat?

[blackprincegts]

Well the cars just clocked over 149 000 km's and it would appear to be the factory standard cat going by what it looked like when i got the got. i doubt the jap owner would hav changed it in the 90 000kms he they had the car for.. You think my cat could be killing off some of the power?

nah its the stock ecu etc... iv been told of someone that can do a remap for really cheap for me that might help things along a bit..

i just spent a few hours re-drilling and cleaning up my pod adapter and I THINK the car seems to be pulling a bit harder up top, but id say the biggest thing that has changed is the engine seems to respond a bit better now iv mucked around with it a bit.

Cubes, so you think its normal that my peak power is coming on before what nissan quote for my motor and already start dropping off hardcore by time it reaches that point, i would have thought that having a pod and exhaust would have pushed it up further if anything..

cheers

[Cubes]

Who's to say the rpm markings on the dyno sheet are 100% accurate?

Rip off the stock cat.. chances are the honey comb is broken in to multiple big chunks.

[Fixxxer]

The RPM data on the bottom of the sheet seems to jump around everywhere. Speed versus RPM will remain constant in one gear. From what I can make out, your RPM jumps from as little as 600rpm per 15km/h increase to 1000rpm per 15km/h increase in speed. This can not happen. Until you can find out your actual RPM I wouldn't bother trying to work out anything, it looks like a normal dynograph to me.

Fixxxer

[Sean'O]

Hey mate,

I've got an r-32 GTS too, I can't really help you with the graph business caus I don't have a great deal of knowledge when it comes to dyno's, but I noticed you said about mounting the Pod in your front bar, how do you do that without cutting into your chassis?

I have had a good look and I can't seem to find any route to cold air?

Sorry for the off topic ness lol

[mad082]

your graph doesn't look that bad for a stock ecu. i'd say that is pretty close to what it should make.

when i had a SSS pulsar (natro sr20) i put it on the dyno and got a similar readout. graph was a little bit more stagered than that. and got about 2kw less.

then my last car before my skyline had a dead smooth curve. no rough spots. the dyno guy said it was one of the smoothest curves he had ever seen. it was a '00 magna with a stock ecu and full exhaust.