Front Pipe + Dump Pipe (Before/After Dyno Results) - 203rwkw Stock ECU/Turbo

[Jay95R33]

Originally posted by EnricoPalazzo

Man wats up with ur ECU

your car is a freak

Congrats!! : )

I've said it before and I'll say it again.

I swear the 1995 ECU's are different, but I'll check when I get mine done.... One day.....

JiMiH - I wouldn't say the difference was massive, but it was noticable.

[Jay95R33]

Benm - if you ever have a look at your ECU, let me know what the MEC number is on it.

The MEC number is located on a black sticker on the lid and the back of the ECU covers, and also stamped on the CPU itself.

It'll be something like MEC-R523 etc. The MEC number is the firmware version in the main CPU.

It'll be interesting to see what you have.

Unless you've got a chipped ECU, then that blows that idea out of the water

J

[turbomad]

Well I've got a 95 model and my A/F ratio was 10.5:1 before the SAFC tune, so either the ECU has been fiddled with or maybe your fuel pump is not flowing the best or down on press, either way good result, I only managed 188rwkw@12psi and that's with the SAFC, no dump or hiflow cat though do you think the dump is a worthwhile mod?

[Guest INASNT]

Originally posted by turbomad

Well I've got a 95 model and my A/F ratio was 10.5:1 before the SAFC tune, so either the ECU has been fiddled with or maybe your fuel pump is not flowing the best or down on press, either way good result, I only managed 188rwkw@12psi and that's with the SAFC, no dump or hiflow cat though do you think the dump is a worthwhile mod?

but look how straight his a/f graph is when on boost. A faulty fuel pump would have it all over the place and not that linear! Sum1 has tinkered with it for sure!

[predator]

You're always a sceptic aren't you insasnt!

Good work there benm.. although to me it sounds like the A/F is running too nicely for it to be a non-modded ECU (in whatever way). Maybe not though, and it could be a '95 ECU difference if there is such a thing.

For some comparison i should have my '94 dynoed this weekend. I have a HKS dump pipe, front pipe to hiflow cat and straight thru 3" (Super Dragger II), and fairly similar setup with i/c, safc, pod, but now running an EBC.. I changed the oil the other week and should have put some new plugs in before it goes on the rollers (or at least gap checked/re-gapped) to give it peak performance. Will see what mine can get up to. Last was 177 but that was the previous owner on a different dyno without the EBC). Seems like a few are getting right up there to reaching 200rwkw without changing the turbo but of course everybody will argue dyno dynamics.

I'll post what I find out this weekend (with hopefully some people who know a lot more than i do!)

Anybody...Can u measure the A/F ratio via the SAFC ? I have an airflow % is that similar?? Can i work it out via some means?

[Guest INASNT]

predator666

we will see if u can beat me this weekend on he same dyno. Thats the only way u can really compare rwkw figures cause all dynos vary.

u need to get the signal from the oxygen sensor to be able to get the a/f ratio. The safc doesent get that sort of signal input i dont think, cant remember what wires i spliced into the ecu!

[whatsisname]

I see what Jay is getting @ here, & have always wondered about this possible '95 ECU difference? After all the Apexi PFC part # changes after late '94. I realise this is due to a number of changes (ignition amp being one of them) but just maybe........?

Actual dyno figures aside, it certainly is interesting how a number of '95 model GTS25t's have very good A/FR's with OEM ECU's!? And seem to make good power (rwkw) with the OEM ECU. Not all 95's do but I've now seen 5 or more that are "freaks".

Bugalug's car - ~204rwkw, stock ECU, perfect A/FR's throughout the rev range (12:1 peak power)

Benm - Well whadda ya' know! The same mod's as Bug's car - 203rwkw, stock ECU & impressive A/FR's given the norm' for a GTS25t (10.0 - 10.8-1)

rev210 - Very impressive 1/4 results! No doubt helped by a good use of basic mods & driver skill (low 60's for a 205) but none the less a high TS of 104mph. Wish you'd have put it on a known local DD dyno to see what the A/FR's were like rev! (prior to the S-AFC2).

There's more to add to this list but I can't recall names @ the moment? Some of the SDU '95 owners are among the list of outstanding OEM ECU results too.

It could be total coincidence that these "freaks" are '95 models? But I've yet to see a 93-94 GTS25t with a stock ECU running the show produce much better than high 10's - low 11's A/FR @ peak power.

[ed]

perhaps we should start compiling stock ECU serial #'s that have a nice AFR? Maybe this will help solve the mystery behind the '95 ECU issue...

Would be very interesting...

[whatsisname]

Couldn't hurt

[predator]

its hard to measure of course once any sort of aftermarket thing goes in.. but i can pull some chip numbers out of my ECU - think my car build is 11/94 so could be an interesting one.

[Guest INASNT]

mines a 96, y couldnt the 95 freaks continue to 96!!

[Jay95R33]

YAY - someone see's what I'm trying to say...... :/

Well, when I get off my butt and take my car to a dyno I'll do a comparison cause I've got a 1993 and a 1995 ECU at home (I popped the tacho output on the 1995 , and got the 1993 to replace it).

That way I can do a direct back to back dyno run on the same dyno 5 minutes appart.

The 1993 ECU is MEC-R521 serial no., and the 1995 ECU is MEC-R523.

Stay tuned

[Steve]

Interesting, falls in line with what a guy I knew was saying, he sells skylines and said he couldnt work out why some seem to go alot harder than others (unmodded)

[Gester]

Well if you dont have a freak car then a S-AFC will do the job wont it?

And this might sound dumb but whats a good AF Ratio to have and why? Thanks

[rev210]

My AFR's non-SAFC are around the 12's at best, for sure.

my ecu is a '522'.

What a rip off I only got the 94 ecu! Thats why my car is so slow! I knew it those bastards! That does it I'm putting the concrete in my boot tonight!

BTW I am pretty sure my R33 is making around 270HP @ the motor maybe a little less. Judging from the cars speed and my previous experiences.

[rev210]

before people ask me "how do I know my AFR's aren't lower?"

Look how much fricken timing I've run on it! Now with the S-afc sorting things I can't run as much if I want the leaner pastures. And I can lean quite alot without dropping below factory advance.

[dojobi]

My pre-SAFC a/f ratios were into the 9s at worst. I have a 93 ECU, so I know it's the first one. If you want me to check out the actual number on the ECU I can.

Cheers,

Michael

[rev210]

Further to my post about guesstimating my afr's I should have said my top end would be 9s and the low/mid range max of 12's (non-closed loop stuff).

[ed]

9's? faaaaaark....that's willy willy wich! :crazy:

[Guest INASNT]

Originally posted by rev210

Further to my post about guesstimating my afr's I should have said my top end would be 9s and the low/mid range max of 12's (non-closed loop stuff).

how is it possible for u to guesstimate your a/f ratio's?? unless u are running behind the car smelling the exhaust fumes. :lol: