How to turbo your N/A

[SKiT_R31]

The N/A and Turbo AFM's physically appear to be identical and I didnt have any issues with mine (S1, green label) but I suppsoe it couldnt hurt to try

Fuel pressure is normal, 45psi at idle, goes up to 55-60psi when revved-appears to be working. Will re-drive the car tomorrow and see if anything feels different, but otherwise going to look at some form of engine management or even an SAFC at this stage and work from there.

Isn't normal fuel pressure 3Bar (43psi) at ATMO? So at idle with a vacuum it should be running somewhere around 32-33psi and with 7psi boost it should peak at about 50psi???

That would mean its running about 10psi too much fuel pressure; If so, that would be pushing your injectors to about 400cc which would richen your mixtures by a good >10% (which if factory takes you to 10-10.5:1 that justifies mixtures down to ~ 9:1 odd).

Just an idea, are you on the stock reg?

Edited August 26, 2011 by SKiT_R31

[blk94r33]

Ah ok. I thought stock fuel pressure was ~45 psi at idle, hose connected? So 10psi higher fuel pressure might be causing it....

And yeah it's the stock reg. I'll try and find what the pressure is meant to be...

[blk94r33]

Ok, general consensus is ~35 psi at idle, ~45psi reg disconnected/atmo pressure. So I do have high fuel pressure. But the reg is still working normally as the pressure changes when the engine is revved or the reg disconnected?

I doubt 10 psi extra can do damage? As most people up the pressure before replacing injectors as a cheat.

I'd say an SAFC is needed and try lean it out a bit. Will check the return line isn't blocked/damper faulty etc before-hand to avoid the problem "fixing itself" and f****** something later on....

[SKiT_R31]

Yeah cool. Nah it wont do any damage, I've played that game before to squeeze more out of small injectors. SAFC sounds like a good option, should make a world of difference for power and economy .

[SKiT_R31]

I wound 37-38% out of my tune accross the board to get it stable at 12.0:1 AFR, you'll nearly max out yours!

[gts25]

Hi Guy's,

I have just completed my NA + T conversion on my R32 and am chuffed with the results.

Here is my setup:

1992 R32 GTS25 - standard RB25DE

R32 GTS-T side mount intercooler and standard pipework

RB20 turbo and standard oil/water lines

Standard Exhaust system

NGK BKR7E plugs

RB20 ECU

Install was straightforward (though time consuming) and the only custom work required was to cut the body for the intercooler pipes and to cut and tee

into the heater hose line for the water return from the turbo.

I was lucky to have purchased a complete running 1993 R32 GTST that could not be complied that I have been using parts (having previously used for 5 stud conversion). This made it easy to refer to the how the setup works.

Performance is great and the car is fun to drive - I have only done an initial drive to make sure all is well but I think the turbo will run out of puff high in the rev range (due to the small turbo I presume).

I have taken photos of every step and intend to put together a D.I.Y guide

Jason

[gts25]

Hi Guy's,

I have just completed my NA + T conversion on my R32 and am chuffed with the results.

Here is my setup:

1992 R32 GTS25 - standard RB25DE

R32 GTS-T side mount intercooler and standard pipework

RB20 turbo and standard oil/water lines

Standard Exhaust system

NGK BKR7E plugs

RB20 ECU

Install was straightforward (though time consuming) and the only custom work required was to cut the body for the intercooler pipes and to cut and tee

into the heater hose line for the water return from the turbo.

I was lucky to have purchased a complete running 1993 R32 GTST that could not be complied that I have been using parts (having previously used for 5 stud conversion). This made it easy to refer to the how the setup works.

Performance is great and the car is fun to drive - I have only done an initial drive to make sure all is well but I think the turbo will run out of puff high in the rev range (due to the small turbo I presume).

I have taken photos of every step and intend to put together a D.I.Y guide

Jason

[blk94r33]

Yeah cool. Nah it wont do any damage, I've played that game before to squeeze more out of small injectors. SAFC sounds like a good option, should make a world of difference for power and economy .

Yeah didn't think so. maybe 60-70+ psi could upset things. With your SAFC, what throttle setting (%/volts) did you have your map switching point? From what I understand, anything below ~%35 throttle when the engine is hot is useless for tuning as the ECU is in closed loop and reads off the O2 sensor? Is this true or does it still use the MAF signal? Ordered a second hand SAFC today, very keen to get it in and get the car back on the dyno!

Only other thing i've noticed is I re-used the connector from the throttle body to the intake/cross-over pipe during the conversion. Will have to get a new piece of silicone hose to replace it in-case it's gone hard and leaking, but doesn't appear to under vacuum.

[blk94r33]

I wound 37-38% out of my tune accross the board to get it stable at 12.0:1 AFR, you'll nearly max out yours!

Yeah not sure how lean i'm going to take it, as i'm running the standard SMIC with extended custom piping to the R/H/F guard. This configuration is working well at ~7psi and the intake doesn't get much above ambient. I think trying for somewhere between ~11:1-~12:1, and slowly increasing the boost while checking for knock should yield a much better result, but keep the whole package reliable.

[blk94r33]

Hi Guy's,

I have just completed my NA + T conversion on my R32 and am chuffed with the results.

Here is my setup:

1992 R32 GTS25 - standard RB25DE

R32 GTS-T side mount intercooler and standard pipework

RB20 turbo and standard oil/water lines

Standard Exhaust system

NGK BKR7E plugs

RB20 ECU

Install was straightforward (though time consuming) and the only custom work required was to cut the body for the intercooler pipes and to cut and tee

into the heater hose line for the water return from the turbo.

I was lucky to have purchased a complete running 1993 R32 GTST that could not be complied that I have been using parts (having previously used for 5 stud conversion). This made it easy to refer to the how the setup works.

Performance is great and the car is fun to drive - I have only done an initial drive to make sure all is well but I think the turbo will run out of puff high in the rev range (due to the small turbo I presume).

I have taken photos of every step and intend to put together a D.I.Y guide

Jason

Congratulations! Another +T! They're good fun to drive as there is alot of punch down low, and very consistent/smooth power across the board. No doubt you'll be looking for more power soon though...

[SKiT_R31]

Yeah didn't think so. maybe 60-70+ psi could upset things. With your SAFC, what throttle setting (%/volts) did you have your map switching point? From what I understand, anything below ~%35 throttle when the engine is hot is useless for tuning as the ECU is in closed loop and reads off the O2 sensor? Is this true or does it still use the MAF signal? Ordered a second hand SAFC today, very keen to get it in and get the car back on the dyno!

Only other thing I’ve noticed is I re-used the connector from the throttle body to the intake/cross-over pipe during the conversion. Will have to get a new piece of silicone hose to replace it in-case it's gone hard and leaking, but doesn't appear to under vacuum.

Disconnect your 02 sensor when tuning. I had my crossover at about 35% actually, it is important to tune this section as closed loop is only active under consistent throttle/revs (or mild changes) if you give the throttle a light stab, or under pretty much all start-stop city driving (unless your stupidly gentle at ~ 10%) it breaks closed loop; If you don’t tune this region your economy will be terrible (and when you do, your part throttle torque will be amazing). I tuned my part throttle at 13:1 until 4000rpm and then to 12.5:1, and my WOT to 12.5:1 until 3500 and then 12:1, richening to 11.5 at ~4500rpm as that’s a common spot for detonation (typical for peak torque rpm) but then back to 12:1 up top.

If you're using any of the factory black rubber 90 degree bends, pull them off and check them. It’s really common for them to split on the inside of the bend and blow open under boost (I've known of 2 that have done this and caused headaches in the past).

[blk94r33]

Disconnect your 02 sensor when tuning. I had my crossover at about 35% actually, it is important to tune this section as closed loop is only active under consistent throttle/revs (or mild changes) if you give the throttle a light stab, or under pretty much all start-stop city driving (unless your stupidly gentle at ~ 10%) it breaks closed loop; If you don't tune this region your economy will be terrible (and when you do, your part throttle torque will be amazing). I tuned my part throttle at 13:1 until 4000rpm and then to 12.5:1, and my WOT to 12.5:1 until 3500 and then 12:1, richening to 11.5 at ~4500rpm as that's a common spot for detonation (typical for peak torque rpm) but then back to 12:1 up top.

If you're using any of the factory black rubber 90 degree bends, pull them off and check them. It's really common for them to split on the inside of the bend and blow open under boost (I've known of 2 that have done this and caused headaches in the past).

Ah ok, so the low throttle map does need tuning for better power/economy. So the O2 sensor is only used during say highway driving, MAF sensor for the rest? Effectively, the low throttle map allows you to tune the car leaner under light load, then richer to prevent ping under heavy load? Cheers for the advice.

I have 2 of the right angle bends, so will take a look and see how they're holding up. Already have a new piece on way for the crossover to throttle-body connection.

[gts25]

Congratulations! Another +T! They're good fun to drive as there is alot of punch down low, and very consistent/smooth power across the board. No doubt you'll be looking for more power soon though...

thanks, yes i am already thinking about more power. I have a 3" Apexi exhaust that i will fit soon.

I have An issue though - i have done 300km of freeway driving (first drive since conversipn) and fuel economy is pretty poor. On this trip i used almost three quarters of a tank, which doesn't sound right. Not sure if its related but when the turbo comes on boost at 2000rpm there is quite an audible turbo whistle. This only occurs under load. If i rev the engine to 2000rpm in park there is no whistle. I have checked all inlet pipes and hoses and everything is nice and tight and i can see no possible places where there could be leaks. The engine does not seem to be running rich (no black tailpipe) and the car idles fine and no issues when driving.

Does anyone have any ideas? Is fuel economy like this normal? Should the turbo whistle? Is the ECU still learning and perhaps explains the poor fuel economy?

Jason

[blk94r33]

thanks, yes i am already thinking about more power. I have a 3" Apexi exhaust that i will fit soon.

I have An issue though - i have done 300km of freeway driving (first drive since conversipn) and fuel economy is pretty poor. On this trip i used almost three quarters of a tank, which doesn't sound right. Not sure if its related but when the turbo comes on boost at 2000rpm there is quite an audible turbo whistle. This only occurs under load. If i rev the engine to 2000rpm in park there is no whistle. I have checked all inlet pipes and hoses and everything is nice and tight and i can see no possible places where there could be leaks. The engine does not seem to be running rich (no black tailpipe) and the car idles fine and no issues when driving.

Does anyone have any ideas? Is fuel economy like this normal? Should the turbo whistle? Is the ECU still learning and perhaps explains the poor fuel economy?

Jason

Fuel economy should be the same, provided your not giving the car a hard time. Did you re-connect the O2 sensor after fitting the dump pipe? How much time are you spending on boost?

[gts25]

Fuel economy should be the same, provided your not giving the car a hard time. Did you re-connect the O2 sensor after fitting the dump pipe? How much time are you spending on boost?

Hi,

Not giving the car a hard time - was on the freeway so mostly cruising. I did re-connect the 02 sensor. I don't have a boost gauge fitted yet so hard to tell what the boost is doing but I did notice that the cruising RPM on the freeway is around 2000 rpm (which my car was on before conversion also) which

is around the same RPM that the turbo comes on boost (only gauging by the whistle). However the turbo does not constantly whistle

Jason

[gts25]

Fuel economy should be the same, provided your not giving the car a hard time. Did you re-connect the O2 sensor after fitting the dump pipe? How much time are you spending on boost?

Hi,

Not giving the car a hard time - was on the freeway so mostly cruising. I did re-connect the 02 sensor. I don't have a boost gauge fitted yet so hard to tell what the boost is doing but I did notice that the cruising RPM on the freeway is around 2000 rpm (which my car was on before conversion also) which

is around the same RPM that the turbo comes on boost (only gauging by the whistle). However the turbo does not constantly whistle

Jason

[blk94r33]

Hi,

Not giving the car a hard time - was on the freeway so mostly cruising. I did re-connect the 02 sensor. I don't have a boost gauge fitted yet so hard to tell what the boost is doing but I did notice that the cruising RPM on the freeway is around 2000 rpm (which my car was on before conversion also) which

is around the same RPM that the turbo comes on boost (only gauging by the whistle). However the turbo does not constantly whistle

Jason

Seems normal. The turbo depends on load and throttle position to actually make boost, so you might hear it spool/whistle, but it's not actually making boost. You said above you're using an RB20 ECU on an RB25DE? I'm assuming it suits the turbo car? As that can f*** everything right up if it's to suit an N/A. Is it tuned to suit the extra .5 litre or just stock?

Fuel economy shouldn't change too much if you only baby the car. Mine easily does ~10L/100km on the highway and could get better if it wasn't so much fun coming out of a 60 zone into a 100 zone in third gear, but have seen anywhere up to 16L/100km around town or giving it a hard time. (Stock RB25DET ECU)

[gts25]

Seems normal. The turbo depends on load and throttle position to actually make boost, so you might hear it spool/whistle, but it's not actually making boost. You said above you're using an RB20 ECU on an RB25DE? I'm assuming it suits the turbo car? As that can f*** everything right up if it's to suit an N/A. Is it tuned to suit the extra .5 litre or just stock?

Fuel economy shouldn't change too much if you only baby the car. Mine easily does ~10L/100km on the highway and could get better if it wasn't so much fun coming out of a 60 zone into a 100 zone in third gear, but have seen anywhere up to 16L/100km around town or giving it a hard time. (Stock RB25DET ECU)

Yep I used ad RB20 ECU - the pinouts are exactly the same except for the fuel control pump modulator which my car being a non-turbo does not have (i am actually thinking about wiring this in to my car). Everything is stock and has not been tuned. I used the RB20 ECU as I thought the fuel maps would better suited to a turbo. Perhaps I should revert back

to my RB25DE CPU and see how the fuel economy is. Not fussed by the whistle sound (sounds great!) as long as it isn't an issue.

Jase

[gts25]

Yep I used ad RB20 ECU - the pinouts are exactly the same except for the fuel control pump modulator which my car being a non-turbo does not have (i am actually thinking about wiring this in to my car). Everything is stock and has not been tuned. I used the RB20 ECU as I thought the fuel maps would better suited to a turbo. Perhaps I should revert back

to my RB25DE CPU and see how the fuel economy is. Not fussed by the whistle sound (sounds great!) as long as it isn't an issue.

Jase

Josh - just to clarify I am using and RB20DET ECU not an RB20DE ECU

Jase

[blk94r33]

Josh - just to clarify I am using and RB20DET ECU not an RB20DE ECU

Jase

No worries, some people have tried using the DE ecu on the DE+T with not-so-good results. They don't have fuel or timing maps to suit the turbo and cause problems. It could be that the extra .5 litre is pushing the RB20 ECU near R&R (extra %25 airflow, even at the same boost) causing your excess fuel usage? Or even if the ECU constantly thinks the car is on boost and richens up accordingly? A re-map/tune will definitely help in all fields...