Jump to content
SAU Community

Recommended Posts

Hi All,

So I have recently got my car tuned for ethanol and have been having some problems

Car: 1992 R32 Gtst

Turbo: Hypergear ATRSS1

ECU: Link G4

Power 380 rwhp @ 22 psi , 700 Nm

The car seems to hit close to 28 Psi by 5000 rpm and then the engine cuts ( programmed to cut if the boost is too high)

Initially one of the lines that goes to the actuator popped off. the car was checked over by the tuner and put on the dyno and given a clean bill of health.

If I use 70% throttle I can rev it 7100 rpm and all is fine, however 100% throttle in 3rd results in misfire/spitting noise at 6000 rpm which I can push through by reducing throttle, but once in fourth it hits 28psi and the engine cuts. Also when it cuts the cat over temp light flashes up.

All hoses are secured and zip tied, solenoids were check, wastegate checked etc. by the tuner the first time. Prior to ethanol, it was putting out 315 rwhp on 98RON with no problems

Is it a problem with the turbo or ECU tuning problem? Any help is appreciated!

get rid of the cat first? Its good power for a RB20det, I'm sure you get more power without the cat.

Check to boost controller and the hoses that goes from it to the actuator and vacuum source. Usually it won't boost creep if its not doing that on the dyno.

get rid of the cat first? Its good power for a RB20det, I'm sure you get more power without the cat.

Check to boost controller and the hoses that goes from it to the actuator and vacuum source. Usually it won't boost creep if its not doing that on the dyno.

It's got a high flow cat on it, need the car legal.

The hoses going to the actuator are all fine, all tight and no splits. Other causes/reasons causing the wastegate not to open?

As mentioned the turbo was running great before the E85 conversion. I am at a loss why it has been on the dyno twice and performed fine but as soon as it hits the road different story

As mentioned the turbo was running great before the E85 conversion. I am at a loss why it has been on the dyno twice and performed fine but as soon as it hits the road different story

Usually it is the opposite as the engine has more ramp load with wheels locked up on the rollers. You can by pass the boost controller and run vacuum source directly into the actuator and see if that helps in any way.

Usually it is the opposite as the engine has more ramp load with wheels locked up on the rollers. You can by pass the boost controller and run vacuum source directly into the actuator and see if that helps in any way.

Double checked there was no vacuum leak by running a new line, same problem

Then I bypassed the boost controlled, vacuum line straight to the actuator and seems a lot better, doesn't over boost. I am guessing the solenoid is malfunctioning not allowing the waste gate to open?

If I bypass the boost controller/solenoid I need to get the car tuned again I am guessing. To run higher boost it will have to go through the controller right

You won't have to retune it to run less boost. Less boost is already covered in a "more boost" tune by definition. You do realise that you can run any boost you like by not pushing the throttle pedal down as much, right?

And yes, to run higher boost you will need to run the boost controller. You can test the solenoid easily enough. Give it 12V + earth and see if it changes state. If it does then the solenoid is fine. If it doesn't then it's munted. If the solenoid checks out, then you have to suspect either the wiring or the controller box itself.

You won't have to retune it to run less boost. Less boost is already covered in a "more boost" tune by definition. You do realise that you can run any boost you like by not pushing the throttle pedal down as much, right?

And yes, to run higher boost you will need to run the boost controller. You can test the solenoid easily enough. Give it 12V + earth and see if it changes state. If it does then the solenoid is fine. If it doesn't then it's munted. If the solenoid checks out, then you have to suspect either the wiring or the controller box itself.

On the track I want to be able to go 100% throttle in 3rd and 4th on a straight and shift close to 6700 rpm/7000 rpm as I can without having to worry about overboosting/boost

So if the car has been tuned with a boost controller and now I have by-passed it completely that will obviously affect the power/torque curve that I had with it yes?

Either way it will go back to the tuner to get sorted

Edited by nj1

On the track I want to be able to go 100% throttle in 3rd and 4th on a straight and shift close to 6700 rpm/7000 rpm as I can without having to worry about overboosting/boost

So if the car has been tuned with a boost controller and now I have by-passed it completely that will obviously affect the power/torque curve that I had with it yes?

Either way it will go back to the tuner to get sorted

I don't think you understood what I wrote at all.

The point about throttle control being a way to run less boost was to make the point that a car set up to run 20 psi can be run at 10 psi by not opening the throttle - and it doesn't need to be retuned to do so because.........surprise surprise, if the tuner knows what he is doing has has tuned the whole map, which includes less load at all rpm points. It is self obvious that this is the case.

So, if you have indeed removed your boost control and are now forced to run less boost, you WON'T need to get it retuned. You would in fact be far better off trying to work out why the boost control wasn't working and get it going again.

wonder if the cat over temp light is used as knock light by the link?

just run it without the boost controller till you either get a new boost control and a dyno check to make sure prev tune is still ok

or buy a turbo tech bleed valve and then get the tune checked on high boost via the bleed valve

really it just sounds like running 28psi and not the 22psi its tuned for it causing the problem

whatever you do if it holds 22psi it should be ok

  • 2 weeks later...

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • Could be. Could also be that they sit around broken more. To be fair, you almost never see one driving around. I see more R chassis GTRs than the Renault ones.
    • Yeah. Nah. This is why I said My bold for my double emphasis. We're not talking about cars tuned to the edge of det here. We're talking about normal cars. Flame propagation speed and the amount of energy required to ignite the fuel are not significant factors when running at 1500-4000 rpm, and medium to light loads, like nearly every car on the road (except twin cab utes which are driven at 6k and 100% load all the time). There is no shortage of ignition energy available in any petrol engine. If there was, we'd all be in deep shit. The calorific value, on a volume basis, is significantly different, between 98 and 91, and that turns up immediately in consumption numbers. You can see the signal easily if you control for the other variables well enough, and/or collect enough stats. As to not seeing any benefit - we had a couple of EF and EL Falcons in the company fleet back in the late 90s and early 2000s. The EEC IV ECU in those things was particularly good at adding in timing as soon as knock headroom improved, which typically came from putting in some 95 or 98. The responsiveness and power improved noticeably, and the fuel consumption dropped considerably, just from going to 95. Less delta from there to 98 - almost not noticeable, compared to the big differences seen between 91 and 95. Way back in the day, when supermarkets first started selling fuel from their own stations, I did thousands of km in FNQ in a small Toyota. I can't remember if it was a Starlet or an early Yaris. Anyway - the supermarket servos were bringing in cheap fuel from Indonesia, and the other servos were still using locally refined gear. The fuel consumption was typically at least 5%, often as much as 8% worse on the Indo shit, presumably because they had a lot more oxygenated component in the brew, and were probably barely meeting the octane spec. Around the same time or maybe a bit later (like 25 years ago), I could tell the difference between Shell 98 and BP 98, and typically preferred to only use Shell then because the Skyline ran so much better on it. Years later I found the realtionship between them had swapped, as a consequence of yet more refinery closures. So I've only used BP 98 since. Although, I must say that I could not fault the odd tank of United 98 that I've run. It's probably the same stuff. It is also very important to remember that these findings are often dependent on region. With most of the refineries in Oz now dead, there's less variability in local stuff, and he majority of our fuels are not even refined here any more anyway. It probably depends more on which SE Asian refinery is currently cheapest to operate.
    • You don't have an R34 service manual for the body do you? Have found plenty for the engine and drivetrain but nothing else
    • If they can dyno them, get them dyno'd, make sure they're not leaking, and if they look okay on the dyno and are performing relatively well, put them in the car.   If they're leaking oil etc, and you feel so inclined, open them up yourself and see what you can do to fix it. The main thing you're trying to do is replace the parts that perish, like seals. You're not attempting to change the valving. You might even be able to find somewhere that has the Tein parts/rebuild kit if you dig hard.
    • Can you also make sure the invoices on the box (And none exist in the boxes) are below our import duty limits... I jest, there's nothing I need to actually purchase and order in. (Unless you can find me a rear diff carrier, brand new, for stupidly cheap, that is for a Toyota Landcruiser, HZJ105R GXL, 2000 year model...)  
×
×
  • Create New...