Stock Turbo Replacement Alternatives C34 II

[ステージア]

Hi All

I've done a lot of reading on here about what people are doing for turbo replacements and 99% of the time people have or are looking at upgrades - exhaust etc. and the discussion seems to revolve around that.

I'm a little old-fashioned and my car is stock and prefer to keep it that way so am looking for a turbo to suit. I want a bolt up solution and I noticed a lot of you lads talk about the CGC high-flow. I just rang them and they said that if I were to do that, the car would require a tune and would not run right without. Is this accurate? Am I to understand that the stock ECU cannot be tuned so this is not a solution as I don't really want to stuff around too much.

Has anybody here done this i.e bolted a CGC high-flow to an otherwise stock car? What were the results? Did it run OK as is?

Any advice or help would be much appreciated.

Thanks all

[Murray_Calavera]

If your car is stock and you want to keep it stock, would you not just get another stock turbo if your current one has failed? 

If what your saying is you want an upgraded bolt on turbo that is so small it won't need any supporting mods or a tune, you might find G2 highflow is what you're after. See link below - 

https://hypergearturbos.com/product/nissan-rb25det-turbocharger-standard-high-flow-service/

[ステージア]

2 minutes ago, Murray_Calavera said:

If your car is stock and you want to keep it stock, would you not just get another stock turbo if your current one has failed? 

If what your saying is you want an upgraded bolt on turbo that is so small it won't need any supporting mods or a tune, you might find G2 highflow is what you're after. See link below - 

https://hypergearturbos.com/product/nissan-rb25det-turbocharger-standard-high-flow-service/

Hi Murray, this looks like the same thing CGC is offering. The issue is because the guts are larger there may be a need for a tune (this is what CGC advised me anyway) which goes to my original question.

[Murray_Calavera]

Just now, ステージア said:

Hi Murray, this looks like the same thing CGC is offering. The issue is because the guts are larger there may be a need for a tune (this is what CGC advised me anyway) which goes to my original question.

From the Hypergear website. G2 is happy with the stock ECU and stock fuel system. 

G2 high flow is capable of making up to 230rwkws. It is happy to hold factory boost, recommended for Rb20det engines and Rb25dets working with factory ecu and fuel system.

[ステージア]

Interesting, I wonder what the difference is between the G2 and CGC highflow is (apart from the non ball-bearing CHRA)?

[GTSBoy]

It's GCG. Not CGC.

You could no doubt get Tao (Hypergear) to rebuild you a stock Hitachi turbo with wheels that are not much different in capacity to the original. He would have to have access to plenty of turbines and compressors that are approximately the same as the stockers. It's just that no-one would want to pay the rebuild cost for a turbo that could have been an actual highflow instead. It will cost the same.

A small highflow will work against the stock ECU. But an important point to remember is that any highflow will flow more gas (and therefore air) at the same boost as stock, so will definitely push your operating point in the ECU's fuel and ignition tables further to the right. In RB25 ECUS, this will lead to more richness and less timing, which is not great. Will use more fuel and make less power than it otherwise could.

An actual proper highflow, a better ECU, some injectors and an AFM are sensible modifications.

[joshuaho96]

If you have a manual I would strongly consider just running a Haltech or comparable ECU that supports AFM, you should be able to develop a base map based off of the factory ECU tables from there.

[Duncan]

You won't be able to run a larger turbo on a stagea with a standard ECU. They are very sensitive to changes in airflow, even a mild boost increase on the standard turbo will throw it off.

If you want to be able to return it to stock, best to plug in an ECU like a PowerFC and put the larger turbo on, reasonably easier to return to stock if you want to.

[RBW49N]

Do you want it to look stock or be stock?

[ステージア]

@RBW49N I want it to be as close to stock so I don't need to change anything else.

@GTSBoy&@DuncanAppreciate the sage technical advice

Thanks everyone for you input. So basically if I want to continue on the keeping the car as stock as possible road, I'm gonna need a either a new or decent second-hand stock turbo.

I guess the next question is what's the best source of either of these?

Ta 

[GTSBoy]

1 minute ago, ステージア said:

I guess the next question is what's the best source of either of these?

There are no new ones. These are ceramic turbine, so all the ones that were going to die from natural causes died years ago and were replaced with the spare stock Nissan had, using it all up. Many have been destroyed since by stupidity (turning the boost up too far).

Essentially, any 2nd hand one you can get that was in good working condition will likely be fine used at stock boost for the rest of time. They've had 20+ years to kill off the weak ones.

Yo get one you'll just need to look at the forums for sales, FB groups (shudder), eBay, Gumtree, etc, for people selling them and try to pick one that is healthy. Import wreckers will also have them and might offer some warranty, which may or may not be useful if you don't install it immediately and discover if it is good or is hiding a problem that wasn't visible on inspection.

[RBW49N]

4 minutes ago, ステージア said:

@RBW49N I want it to be as close to stock so I don't need to change anything else.

@GTSBoy&@DuncanAppreciate the sage technical advice

Thanks everyone for you input. So basically if I want to continue on the keeping the car as stock as possible road, I'm gonna need a either a new or decent second-hand stock turbo.

I guess the next question is what's the best source of either of these?

Ta 

There is a always a few for sale on FB marketplace and they do pop up here from time to time. I have one that needs a rebuild if you want it you can have it just come and get it. Then there would be very little down time

[joshuaho96]

Is there even an ECU that can play nicely with the 4AT in these Stageas? I don't mean like a Motec where in theory you could write all of the code to handle that stuff, actual support where there's a base map that is pretty much spot-on for the transmission, just need to change some calibration values to get things like shift mapping to suit, maybe some timing retard adjustments to get the shifts smoothed out as well.

[RBW49N]

3 minutes ago, joshuaho96 said:

Is there even an ECU that can play nicely with the 4AT in these Stageas? I don't mean like a Motec where in theory you could write all of the code to handle that stuff, actual support where there's a base map that is pretty much spot-on for the transmission, just need to change some calibration values to get things like shift mapping to suit, maybe some timing retard adjustments to get the shifts smoothed out as well.

Yes It can be done with the Haltech elite 2500. Full series 2 auto, fuel and ignition control. 

Edited February 10, 2021 by RBW49N

[GTSBoy]

Yeah, it's getting better after decades of being nearly impossible.