R33 GTR running -9 with no tune

[677_GTR]

Hi guys, I’m new to the GTR scene. Picked up an R33 GTR earlier this year that needs a lot of love.
I’ve been going through the hot side, changing all the gaskets and while it was all off I managed to score a set of -9s. It still had the stock ceramics so I was pretty happy to get the 2860s. 
I live in a small country in the pacific with 0 performance car scene. No dyno’s no performance parts, let alone stock parts for a skyline. I order everything from Australia and do it myself. This means I’ll be running the stock ECU. Maybe down the track I’ll get an aftermarket set up and do a remote tune. 
Will the car run -9s on stock tune safely? 
I have a very heavy foot so I really hope so 😂

 

thanks guys 
 

[GTSBoy]

24 minutes ago, 677_GTR said:

Will the car run -9s on stock tune safely? 

Only if you do not

24 minutes ago, 677_GTR said:

heavy foot

You will not be able to drive it with any serious load without risk of it pinging, which will either slowly or rapidly kill it, depending on how bad it is.

[677_GTR]

Thank you for the feedback bro. Looks like it’ll have to stay off the road till it gets an ecu 

[Dose Pipe Sutututu]

3 hours ago, 677_GTR said:

Will the car run -9s on stock tune safely? 

you would be better off installing a Haltech (or similar) with a wideband O2, run the base map with O2 feedback on at gate pressure.

[joshuaho96]

4 hours ago, 677_GTR said:

Hi guys, I’m new to the GTR scene. Picked up an R33 GTR earlier this year that needs a lot of love.
I’ve been going through the hot side, changing all the gaskets and while it was all off I managed to score a set of -9s. It still had the stock ceramics so I was pretty happy to get the 2860s. 
I live in a small country in the pacific with 0 performance car scene. No dyno’s no performance parts, let alone stock parts for a skyline. I order everything from Australia and do it myself. This means I’ll be running the stock ECU. Maybe down the track I’ll get an aftermarket set up and do a remote tune. 
Will the car run -9s on stock tune safely? 
I have a very heavy foot so I really hope so 😂

 

thanks guys 
 

Run a 7 psi wastegate and wastegate boost and it might be ok on the stock ECU. Basically you cannot run past the last load cell by a significant margin.

[Murray_Calavera]

1 hour ago, joshuaho96 said:

Run a 7 psi wastegate and wastegate boost and it might be ok on the stock ECU. Basically you cannot run past the last load cell by a significant margin.

Would you do this in your own car?

[Dose Pipe Sutututu]

If this was my own car, I would pull about 5 degrees off the CAS, run a wideband, and if that seems ok, send it.

[joshuaho96]

1 hour ago, Murray_Calavera said:

Would you do this in your own car?

That's basically how I've been driving my R33 for a while now. GTIII-SS running wastegate boost. It makes no more power than stock because the turbos aren't flowing any more air than stock. Eventually though I need to fix this so it can actually drive as it should.

[GTSBoy]

53 minutes ago, joshuaho96 said:

It makes no more power than stock because the turbos aren't flowing any more air than stock

Yeah - that's not true.

Larger turbos flow more at the same boost. By definition. I've always found it funny when the claim of same flow same power because same boost is made. The turbine is larger, therefore will put up a lower restriction to flow at any given flow, cf the stock one. Hence, you need less boost to make the same flow through the whole system. Hence, when you have the same boost as before, you must have more flow.

-5s are a pretty decent bit bigger than stock.

[Murray_Calavera]

1 hour ago, joshuaho96 said:

That's basically how I've been driving my R33 for a while now. GTIII-SS running wastegate boost. It makes no more power than stock because the turbos aren't flowing any more air than stock. Eventually though I need to fix this so it can actually drive as it should.

Wow yeah ok. Given how specific you are about your car, I'm very surprised you are happy to do that. 

As a bare minimum, without having a wideband gauge in the car or running it up on the dyno to check mixtures, there is no way I'd do that to my car. 

20 minutes ago, GTSBoy said:

Larger turbos flow more at the same boost. By definition. I've always found it funny when the claim of same flow same power because same boost is made.

You beat me to it, was going to say just this. 

[joshuaho96]

39 minutes ago, GTSBoy said:

Yeah - that's not true.

Larger turbos flow more at the same boost. By definition. I've always found it funny when the claim of same flow same power because same boost is made. The turbine is larger, therefore will put up a lower restriction to flow at any given flow, cf the stock one. Hence, you need less boost to make the same flow through the whole system. Hence, when you have the same boost as before, you must have more flow.

-5s are a pretty decent bit bigger than stock.

Right, but I'm saying on the stock ECU measured airmass from the MAF is no higher than stock. So it's accounting for the higher flow rate iso-manifold pressure. You just have to keep turning down the boost until you're within the stock tune's load scale. If you run off the end there's no telling what will happen.

This does mean there's zero benefit to the turbos you're running vs stock, if anything it's just a straight downgrade because the transient response is worse, you don't even get the ECU's boost solenoid helping to pull the wastegate closed during initial spool, and peak power is only whatever the factory map can give you before you hit the R&R corner. On a -9 I would bet that you would have to change out the wastegate spring once you have a real ECU and you're tuning it for real.

I'm not saying this is a remotely ideal state of affairs, it's just a way to keep it driveable until you can get a proper tune done.

[GTSBoy]

1 hour ago, joshuaho96 said:

You just have to keep turning down the boost until you're within the stock tune's load scale. If you run off the end there's no telling what will happen.

So while the second sentence is completely correct and the whole point of the conversation, the first sentence bears consideration. If this bloke is just hoping to throw big turbos on and drive it around, because there are no helpful facilities at all in his tropical paradise** then he likely has zero chance of even knowing what the TP is on the last column in the stock maps, let alone know whether the ECU is operating anywhere near it or past it. So the point is very very moot.

And, per what I said before, at stock boost on those turbos, you may well be off the end of the map.

**I'm just back from Vanuatu, so I know exactly what small Pacific nations can be like wrt paradise without requisite facilities.

But it's not even that simple. I put a high flow on my car and had to drive it around without a proper tune because of the lack of opportunity*** to put the bigger AFM and injectors into it to allow it to be tuned. I had to turn the boost down to less than I had before, and back off the boost controller's ramp, because it was exploring parts of the map that it didn't drive in before, and really couldn't access for tuning on the dyno either, and so was pinging. It was still well within the last column, because when I first**** set up the Nistune on the Neo I rescaled all axes of the maps to give some more space to explore.

***Family dyno was broken

****This was 13 years ago, and the TIM thing wasn't a thing then and so TP would definitely grow when pushing past the stock tune's limits.

[joshuaho96]

34 minutes ago, GTSBoy said:

So while the second sentence is completely correct and the whole point of the conversation, the first sentence bears consideration. If this bloke is just hoping to throw big turbos on and drive it around, because there are no helpful facilities at all in his tropical paradise** then he likely has zero chance of even knowing what the TP is on the last column in the stock maps, let alone know whether the ECU is operating anywhere near it or past it. So the point is very very moot.

And, per what I said before, at stock boost on those turbos, you may well be off the end of the map.

**I'm just back from Vanuatu, so I know exactly what small Pacific nations can be like wrt paradise without requisite facilities.

But it's not even that simple. I put a high flow on my car and had to drive it around with a proper tune because of the lack of opportunity*** to put the bigger AFM and injectors into it to allow it to be tuned. I had to turn the boost down to less than I had before, and back off the boost controller's ramp, because it was exploring parts of the map that it didn't drive in before, and really couldn't access for tuning on the dyno either, and so was pinging. It was still well within the last column, because when I first**** set up the Nistune on the Neo I rescaled all axes of the maps to give some more space to explore.

***Family dyno was broken

****This was 13 years ago, and the TIM thing wasn't a thing then and so TP would definitely grow when pushing past the stock tune's limits.

Yeah I suspect even if you hold airmass per cycle/cylinder constant if you get too far away from stock you're still going to have problems running the factory tune within the bounds of the factory load scale. Cams, different displacement/rod ratio, etc. I'm just lucky that the GTIII-SS with wastegate boost + CA compliance cats is pretty much equivalent to stock turbos. When I have actual space I can finally get it tuned and modify the fuel system for flex fuel to 100% handle any detonation concerns when cranking the boost to whatever those dinky turbos can put out.