Series II ECU into a Series I?

[sloth]

Hi,

At a dyno day I noticed that a R33 Series II GTS25t produced a much more linear power curve than my Series I. A performance workshop has told me that this is entirely normal, and it's because the Series II ECU is superior.

Is it reasonably easy to install a Series II ECU into a Series I?

Thanks,

Greg.

[sewid]

Hrmm. I believe it would be very easy but if you are trying to replace the stock ECU with another stock ECU I have heard that the 1995 model is the pick of the bunch.

I think the money it would take to find a 1995 ECU would be better put into getting a PowerFC.

The ECU itself is very simple to pull out, you can find it behind the passenger side kick panel.

[JimX]

Why is the 95 model the best?

[sewid]

I cannot verify this with any emperical data, it is purely anecdotal, but it has "better" maps.

I believe there were some posts here once with some graphs representing the maps from 95 ECU's and other year stock ECU's. I will use the search button now.

[sewid]

Here is the relevant post:

http://www.skylinesaustralia.com/forums/sh...hlight=1995+ecu

[wannabe]

At the risk of sounding like a complete tool (may well be true!) would the linear curve not have anything to do with variable valve timing?

This is more of a question than a statement!

[sewid]

Dont want to sound blunt but, whats your point?

I believe the VVT between all RB25DET engines is the same until you reach the late model engines, that is the NEO from the R34 and perhaps some very late model R33's or Stageas.

[wannabe]

Fair enough i was unaware that the VVT was the same on all RB25DET until much later models. Thus my question has been answered and i will shut up...

[RbHed]

yay i got a 95 line

[JimX]

The 95 ECU is well over-rated. Get a PowerFC and you'll see the light

[sewid]

Fair enough i was unaware that the VVT was the same on all RB25DET until much later models. Thus my question has been answered and i will shut up...

Hehe dont shutup, its a good question and I have no proof to back myself up so either of us could be right.

On topic, I agree that as an "upgrade" the 95 ECU is only worthwhile if you can get it for free or swap over your existing 93, 94 ECU. It is well overrated.

[hippy]

i think you guys may be mistaken ... from what i've read and heard i think the reason why 95 is better is that the ecu takes to mods better ... i've heard of disaster stories with mods and early r33's ... in that the power was less with the mods ... but the 95s take it better ... but nowhere as good as a powerfc ... thats just what i think .

[N I B]

After a full week of Power FCs on the dyno anything would be better.

I will test a few different factory ECUs for you next week and post the results.

[sloth]

Thanks for the info everyone. My car is a '95 model but I haven't checked my ECU yet. I do recall the workshop being surprised at the power gain after installing a 3" turbo back, high-flow cat and pod filter - it went from 121kW up to 147kW, however they said the timing had to be pushed back a fair bit as well. (they said that it appeared to have been tuned for the Japanese fuel)

I now have 168kW @10.5psi - nothing wrong with my maximum power, but it would be nice to have the nice linear power delivery that I remember seeing on the Series 2 dyno plot. I have an EBC which has helped to bring on the power earlier (by eliminating the two level boost staging which the factory boost controller produces), but it still doesn't look as linear as I remember the Series 2 being.

Just for kicks, is anyone able to post a Series 2 (in stock form, or close to) dyno plot?

Greg.

[sewid]

i think you guys may be mistaken ... from what i've read and heard i think the reason why 95 is better is that the ecu takes to mods better ... i've heard of disaster stories with mods and early r33's ... in that the power was less with the mods ... but the 95s take it better ... but nowhere as good as a powerfc    ... thats just what i think .

Yes. In 1995 they included magical abilities into the ECU. Each one is factory blessed by a registered fairy and sat upon by a japanese school girl before being excreted into the car at high velocity by a small leprichaun with a big butt.

This makes about as much sense as your post with about as much logic to back it up.

[maxim]

Yes. In 1995 they included magical abilities into the ECU. Each one is factory blessed by a registered fairy and sat upon by a japanese school girl before being excreted into the car at high velocity by a small leprichaun with a big butt.

This makes about as much sense as your post with about as much logic to back it up.

[N I B]

I tested a few different ECUs this week and found none any better than the others but Tomei ECUs have about 10% less power acoss the rev range but no speed cut and a lot higher rev limit.Boost was the same the fuel was good by jap standards but the timing was soft.