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Discussion Starter #1
Hi everyone:

Let me give you a clue about the problem. I was very happy running 17 psi in my 1993 GTS25t, then the turbo died, it exploded and I had to take the turbine pieces of the intercooler and the piping before it, after it I didn't find anything bigger than shinning dots of aluminum, I cleaned anyway the intake manifold and all the piping. Fortunately I found a very similar garret turbo and made it re-bore to make it easier to get 17 psi. I drove the car for about 3 days with 7-10 psi, it was perfect and the turbo had much better response than the blown one. When I tried to raise the boost the car immediately started to cough and splutter and it wouldn't go further than 4500 rpm. I posted previously the problem and got some answers to try out. So far i have tried the following:

1) Checked the coils OK
2) Checked the O2 sensor and gave me in idle 0.4V and 2500 rpm between 0.4 and 0.8V, some times drops to 0.2(the manual says that between 0.6 and 1V. is OK so is that the problem? Higher voltage
3) Checked the compression of the pistons and they are even and OK.
4) checked the plugs (they had kind a brick color) but no signs of damage, and cleaned them out.
5) Checked the AFM, the hot wire seems pretty healthy, the voltage in idle is 0.8 constant and when in 2500 rpm is 1.4 approximately, when accelerating more (no load.. in neutral) got readings of 3.8 V. so seems to be OK?. Well with no load maybe is not sucking that much air as when running it, so still with a question mark on it.
6) Checked the fuel pump pressure, I blocked for an instant the return rail and the pressure got up to 120 psi. When not blocked 40 psi (accelerating). Since I don't know the original values, maybe the regulator is not good?

Finally it makes me think a lot about the turbo, why the problem would start right after installing the new one? is it a coincidence or is it the turbo that has something when boosting that makes the car splutter like that?. Maybe the actuator has problems to move the wastegate and makes it close and opne slowly so it would cause the problem?

I need help guys!!! THANKS IN ADVANCED.
 

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Are you running the standard ecu/afm/injectors etc...?

And are you using a boost controller?

If the actuator on the old turbo was altered to give 17 psi on a standard turbo
i'm not surprised it went BANG.

1 BAR (14PSI) is the max on a standard turbo with standard ecu/afm etc.


If you do push more then you risk runnung so weak you will hole a piston or 2.

Mmmmmmmmmm interesting:eek:
 

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Discussion Starter #4
Well, I have wiseco pistons, water alcohol injection, FMIC, 3"complete exahust, apexi filter... everything else on the engine is stock.

I made a thread on the actuator tube so it can be adjusted and harder for the actuator to get moving, so I can set it between 7 psi and 17 psi. The thing about the 17 psi is that since I live at 12000 feet or 3600 meters above the sea level, the air is much thiner, so the atmospheric pressure at that altitude is 10 psi instead of 14.7 as the sea level is. So the absolute pressure with 15 psi (turbo pressure) at sea level would be 14.7+15 = 29.7 psi which the ECU, AFM and injectors are capable to handle. SO trying to get that maximum of 29.7 psi at my conditions would be. ATmospheric pressure = 10 psi + 19 psi (turbo pressure) would get me to th 29 psi. That's why I still keep everything else stock on it, but planning to go bigger though ;)

ANother option that I thought of is that some little turbine pieces maybe went in to the engine and are staying at the valves having the compression filter by that little hole?

Help please!! THANKS.
 

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Well, I have wiseco pistons, water alcohol injection, FMIC, 3"complete exahust, apexi filter... everything else on the engine is stock.

I made a thread on the actuator tube so it can be adjusted and harder for the actuator to get moving, so I can set it between 7 psi and 17 psi. The thing about the 17 psi is that since I live at 12000 feet or 3600 meters above the sea level, the air is much thiner, so the atmospheric pressure at that altitude is 10 psi instead of 14.7 as the sea level is. So the absolute pressure with 15 psi (turbo pressure) at sea level would be 14.7+15 = 29.7 psi which the ECU, AFM and injectors are capable to handle. SO trying to get that maximum of 29.7 psi at my conditions would be. ATmospheric pressure = 10 psi + 19 psi (turbo pressure) would get me to th 29 psi. That's why I still keep everything else stock on it, but planning to go bigger though ;)

ANother option that I thought of is that some little turbine pieces maybe went in to the engine and are staying at the valves having the compression filter by that little hole?

Help please!! THANKS.

I dont think you could get that psi on standard parts on the moon, never mind where you are LOL.

:screwy: :dogpile:

I would get it checked out a tuner/garage before embarking on upping the boost again and also to see if you have ceramic/steel bits of turbo fouling the valves, as you said, or its BANG again.

Commpression filter could be piston:Uzi: Not good.

Good luck
 

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Discussion Starter #6
Well I did a couple of races with 17 psi with no problems... thank you anyway...

Anyone else have any other idea before I open the engine and look what's going on?

THANKS.
 

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Where in the world are you CIDACO?

Im sure every1 will agree, you were very lucky the turbo didnt let go earlier @ 17psi!

Ive got a garrett steel internal oem one and ive been told 20psi is absolute max with:

Bigger injectors
Better Ecu
Steel head gasket
Z32 or Q45 afm
And Mapped on a rolling road.

Have you done any of the above??????????????????????????????
 

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anyone??:notworthy
What other goodies do you have fitted?

Are you running standard ecu,afm, injectors etc.......?

If so 1 bar MAX as they will max out by then.:drivin:
 

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Discussion Starter #12
I didn't modify any of he above.. just the head gasket, and the wisecos are rated at 8.4:1, water injection also does a lot to help detonation...

I live in La Paz-BOLIVIA (3600 meters above the sea level), where in the airport many People will arrive directly to an oxigen mask...and where I can easily bit (at 7 psi) a BMW M3 2001 due to the thin air... this is because of the atmospheric pressure, which is only 10 psi at this altitude, where NA cars have 34% less power due to this fact. Turbo cars though can loose up to 20%... I didn't believe what in theory was the loss of power, but when I drove to sea level with the car it felt like having twice as power as before!!! what a difference.

Well of course my turbo died because of having it at that high pressure!!, but it worked for about six months like that. Now I found the same one and re-bored it it's also with steel blades...it feels really well.

Maybe you don't believe me... but It happened, you would be surprised with the lack of power your car will experience if you go above 2500 meters above the sea level.... I'll try to post some videos of the car at 17 psi... not as good as it sounds as it's equivalent to ~11 psi at sea level, the best time I got on a 1/4 mile with 17 psi was 14 sec flat... no signs of being lean or anything.... just steady power while reving...

Going back to my problem... I'm still restricted to the 10 psi and I can't get , because of that hesitation.. misfiring, spluttering, stuttering, I don't know how to explain, I'm expecting this Blatz software to arrive so I can monitor the car while driving... and I'm cleaning the coils today as explained on one of this forum. I found also a rb20DE of a friend of mine... I'll swap my AFM with it as it seems to be the same, well that I'm not pretty sure but I found it here also, and it seems to be the same, please correct me if I;m wrong.

Wish me luck, I'll post back as soon as I try it.

Thanks for all the help.
 

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Discussion Starter #13
Problem Resolved Missfiring!

You guys helped me big time!!

Thanks for all the replies, I finally cleaned the coil packs and found them so dirty and almost gray!! after cleaning them I went for a ride.... and the missfiring was gone!!! so I decided to clean them all again and let them shine, I have taped them too and works great, anyways the coilpacks seem to have some time and that are about to give up, so I;m going to buy some others.

Do you guys know if tha coil packs from the RB20DE AND RB25DE are the same as the RB25DET? all your help is highly appreciated!!!

Cidaco.

PD. As soon as I have the car with the new coils I'll post a video with the 17 psi.:dogpile:
 

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cidaco as far as i'm aware the coil pack are different.
 

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You guys helped me big time!!

Thanks for all the replies, I finally cleaned the coil packs and found them so dirty and almost gray!! after cleaning them I went for a ride.... and the missfiring was gone!!! so I decided to clean them all again and let them shine, I have taped them too and works great, anyways the coilpacks seem to have some time and that are about to give up, so I;m going to buy some others.

Do you guys know if tha coil packs from the RB20DE AND RB25DE are the same as the RB25DET? all your help is highly appreciated!!!

Cidaco.

PD. As soon as I have the car with the new coils I'll post a video with the 17 psi.:dogpile:
Oh good, glad its ok now.

These are the coil packs to go for:

http://cgi.ebay.co.uk/SPLITFIRE-COI...ryZ32624QQrdZ1QQssPageNameZWD2VQQcmdZViewItem.

If you get a mis-fire again, it could be the Lamda sensor off your turbo elbow.

Its a common fault on our car.:grinno:
 

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Now theres a potentially interested thread... the effects of air pressure of turbo vs na vehicles such as the M3.... but it sounds way above my head lol....
 

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Now theres a potentially interested thread... the effects of air pressure of turbo vs na vehicles such as the M3.... but it sounds way above my head lol....
I can give you an example. I was driving up the Fernpass, (pass over the Alps between Austria and Germany) As I was going up, I had a Play with a Ferrari 360 Modena, He had me for a bit at first but up hill at about 2000+ meters I out accelerated him, the look on his and his girlfriends face was precious!

NA cars depend on atmospheric pressure to fill their cylinders after the downward stroke of the piston creates a low pressure area, The greater the difference in pressure the faster the air will move, unfortunately regardless of outside pressure, the "Vacumm" (for want of a better term since it is not really a vacumm) created remains relatively constant. Assuming the amount of oxygen was the same percentage of atmosphere(it's not at high altitude, it's lower!) the car would lose the same percentage of horsepower as the pressure differential. IE Ferrari 14.5 psi at sea level 400hp at 11.8 psi = 325hp
But it gets worse fo NA cars, as I said before the air velocity will be less because of the lower pressure differential. between 7 and 15% so his volumetric efficiency would be down to 80 - 90% from the typical ferrari 95 - 98% so he was down to nearly 300 hp before we factor in the fact that the higher you go the less percentage of the atmosphere is oxygen.
So Now he is less than 300 at the flywheel!
I could still hear my wastegate opening, with my boost controller set to 11 psi! so I was only losing the HP due to the lower percentage of oxygen as the manual spring type boost controller I have works on force, not pressure differential so I had most of my 331 hp at the HUBS not flywheel.

Bottom line NA Cars lose lots, turbos were originally designed to allow aircraft to fly at higher altitudes!

Go turbos!:cheers:
 

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i can understand this two weeks ago i was in zermatt switzerland at the top of the matterhorn 3880 approx and i was having real difficulity breathing if i did anything but a really slow walk ... altitude really makes a massive difference
i had to leave my 32gtr in the village of tasch in the bottom of the valley so i don't know how she would have performed up there !!
 

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Discussion Starter #19
Great you guys tested the NA cars vs turbo ones!! at high altitude, This weekend I went for a 1600 km trip to a sea level area to look for coil packs...that is in Chile, I went down from 4010 mts to 0, well it took about 180 kms downhill... I found such a difference... torque is really really more at sea level, acceleration as well.... I felt frustrated when climbing back to my Country...

Anyways I already have new my coil packs from a RB25DE that turned out to be the exactly same as the rb25DET, same part number and works great, this weekend we will have 1/4 mile race at 3900 mts above the sea level, as I said before I will be pushing 17 psi, and I'll post the videos...

Wish me luck....

Cidaco
 
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