Rb25det Making Boost (when Reving)

[WogsRus]

if you set it to 15, according to the crank and the copmputer is telling you it's 15, then the timming is way off.

If it runs like crap at 15, i sugest the timing is out a toth or two.

Sometimes too, the key on the harmonic balancer brakes, and the referances are all screrwed up, so 15 is actualy 40 or somethign stupid.

[blind_elk]

As you stand in front of the engine bay and stare down on the crank pulley, the timing marks move from left to right (in LHD, that's from passenger side to driver side). So the first mark you see is 30 BTDC, then 5 deg decrements to 0 (TDC). (Note - 15 BTDC is the same mark, regardless of which end of the marks you start from)

I have observed that some timing lights "double" the reading, so to get 15 BTDC actual, you need to set it up at 30 BTDC.

[Cubes]

I have observed that some timing lights "double" the reading, so to get 15 BTDC actual, you need to set it up at 30 BTDC.

I've seen this also. Double looping the wire did the trick for me. Why? I have No idea.

[SECURITY]

you could double loop the wire OR only clip on one side of the timing light (i.e. dont clip it), if yours is the kind that springs then as cubes said just double loop it.

and mine goes to FULL boost on neutral. but its an auto and timing is at 20deg on autos. may have something to do with that.

[tomtomtuning]

UPDATE !!!!

Today I pulled the front cover off.

I set the crank to TDC (top dead center)

Both Cam gears lined up with the marks

The timing belt did have some flop to it

instead of just adjusting the tension more

I will be replacing the belt with an aftermarket on (such as the Greddy belt)

I also removed the Cam/Rocker cover's

And the cams are just fine.

So new timing belt is going on this weekend, putting it all back together.

But I still think its going to make boost...

Any other ideas?

I spoke to a couple of my buddies who have high horse power cars (knowledgeable)

and they said its ok normal to see the turbo boost some on no load. but it will boost more on a load...

but then I speak to other ppl who say there car doesn't make 1psi when up rev it all the way to the revlimter

[R34GTFOUR]

UPDATE !!!!

Today I pulled the front cover off.

I set the crank to TDC (top dead center)

Both Cam gears lined up with the marks

The timing belt did have some flop to it

instead of just adjusting the tension more

I will be replacing the belt with an aftermarket on (such as the Greddy belt)

I also removed the Cam/Rocker cover's

And the cams are just fine.

So new timing belt is going on this weekend, putting it all back together.

But I still think its going to make boost...

Any other ideas?

I spoke to a couple of my buddies who have high horse power cars (knowledgeable)

and they said its ok normal to see the turbo boost some on no load. but it will boost more on a load...

but then I speak to other ppl who say there car doesn't make 1psi when up rev it all the way to the revlimter

have you tried to change your cas over with another one just to try and take it out of the equation? It could be a dodgy cas giving it wrong timing. What about the boost gauge, have you tried to use one of your mates? It could just be a dodgy gauge aswell??

I havent seen the footage, but at idle does the turbo actually sould like its spooling, or is it quite? Im in the middle of putting a n/a sr20 with a bolted on turbo in a mates s14, and we had the timing way too retarded and it was hitting boost at idle, but you could hear the turbo spooling, and when you turned it off, the turbo fluttered like as if you were driving and backed off on the accelerator. Does the turbo compressor surge or "flutter" when you turn the motor off.

Turbos need load to get boost, or an antilag system. When you flatten the accelerator in neurtal, your creating some load on the motor, not as much as normal driving, but still theres enough load to create some boost. Theres no way of getting boost at idle without antilag, for the simple reason that there isnt enough load.

Theres two common antilag systems. The first is aggressive air injection, and the second works off igntion timing. So if anybody is definately getting boost at idle, and you will be able to hear the turbo spool, i would say its timing related.

[SECURITY]

have you tried to change your cas over with another one just to try and take it out of the equation? It could be a dodgy cas giving it wrong timing. What about the boost gauge, have you tried to use one of your mates? It could just be a dodgy gauge aswell??

I havent seen the footage, but at idle does the turbo actually sould like its spooling, or is it quite? Im in the middle of putting a n/a sr20 with a bolted on turbo in a mates s14, and we had the timing way too retarded and it was hitting boost at idle, but you could hear the turbo spooling, and when you turned it off, the turbo fluttered like as if you were driving and backed off on the accelerator. Does the turbo compressor surge or "flutter" when you turn the motor off.

Turbos need load to get boost, or an antilag system. When you flatten the accelerator in neurtal, your creating some load on the motor, not as much as normal driving, but still theres enough load to create some boost. Theres no way of getting boost at idle without antilag, for the simple reason that there isnt enough load.

Theres two common antilag systems. The first is aggressive air injection, and the second works off igntion timing. So if anybody is definately getting boost at idle, and you will be able to hear the turbo spool, i would say its timing related.

so explain to me how my car is at 20deg and making full boost (12psi) at idle.

[Cubes]

I'll test mine tonight.

[tomtomtuning]

have you tried to change your cas over with another one just to try and take it out of the equation? It could be a dodgy cas giving it wrong timing. What about the boost gauge, have you tried to use one of your mates? It could just be a dodgy gauge aswell??

I havent seen the footage, but at idle does the turbo actually sould like its spooling, or is it quite? Im in the middle of putting a n/a sr20 with a bolted on turbo in a mates s14, and we had the timing way too retarded and it was hitting boost at idle, but you could hear the turbo spooling, and when you turned it off, the turbo fluttered like as if you were driving and backed off on the accelerator. Does the turbo compressor surge or "flutter" when you turn the motor off.

Turbos need load to get boost, or an antilag system. When you flatten the accelerator in neurtal, your creating some load on the motor, not as much as normal driving, but still theres enough load to create some boost. Theres no way of getting boost at idle without antilag, for the simple reason that there isnt enough load.

Theres two common antilag systems. The first is aggressive air injection, and the second works off igntion timing. So if anybody is definately getting boost at idle, and you will be able to hear the turbo spool, i would say its timing related.

Being that I am in the USA, it is not easy to try another CAS.

But I do think the CAS from a Q45 is the same as the RB25.

I did not get to try another boost gauge.

As soon as I got to the garage I took to belt cover off

And since I decided to replace the belt, I began removing it.

So until I get the new timing belt, the motor is disabled.

Once I get it back together, I am going to fire it up again, and try another gauge.

If I set the timing to anything below 10* I can begin to hear the turbo spool

but at 15* its fine. and when I rev it up.. and it makes boost. I can see my piping couplers expand due to boost

So I know its making some sort of boost.

I would really appreciated, if people try it out on there car and let me know how it turns out.

if also want to buy the Consult to hook up to my car, so if can see engine statistics

to better determined what is going on with the engine

[Cubes]

Yep mine makes boost also.

But it does require a hard 6000rpm rev.

[tomtomtuning]

So about 3 people have agreed that there care makes boost when reving it.

my car also requires me to rev it up pretty high in order to get the boost.

[tomtomtuning]

So tomorrow the new timing belt should be here.

I will instal the belt, make sure every thing is on point.

Then fire it up again.

I will post videos of the outcome.

[tomtomtuning]

Power Enterprise belt installed

Timing on point

I am now waiting for some other new parts i ordered

Like new Radiator, Fans and Cooling panel

Once that gets here ill start it back up and see how things turn out.

An other thing id like to mention is...

being that i have the Greddy IM and Q45 Throttle body, larger IC piping and a bigger FMIC With the Stock T3.

Do you think since there is alot more Air passing though the motor now that it would have enough load to spin that little turbo?

Well updates to come !!!

[mad082]

tried to make boost in my mates stanza with a sr20 in it. i think i got it to 1psi bouncing it off the pre-stage rev limiter at 6000rpm.... but it's a 500hp+ car, so the turbo is pretty huge.

[R34GTFOUR]

so explain to me how my car is at 20deg and making full boost (12psi) at idle.

depends on what set-up you have. If its a stock motor/turbo, idleing at the stock 650rpm with the timing set at 20degrees btdc i dont believe there is anyway you are making 12psi at idle, you will definately be hitting some sort of boost while free-reving but even then you shouldnt be hitting full boost. Like i said before, people can choose an antilag system where the timing is not affected, but that requires air injection which is extremely hard on the turbo. Even the other method by retarding the timing to achieve boost at idle is still very hard on the turbo, and will shorten the life massively. Most turbo motors should be able to hit some sort of boost by free-reving the motor in neutral, but that only because by flattening the accelerator till high revs or limiter is putting the motor under load, try do that only half throttle to limiter and see what boost your getting, you wont get any because no load..

turbos cant just make boost, they need certain factors to be present to do it

Edited April 10, 2007 by R34GTFOUR

[R34GTFOUR]

Power Enterprise belt installed

Timing on point

I am now waiting for some other new parts i ordered

Like new Radiator, Fans and Cooling panel

Once that gets here ill start it back up and see how things turn out.

An other thing id like to mention is...

being that i have the Greddy IM and Q45 Throttle body, larger IC piping and a bigger FMIC With the Stock T3.

Do you think since there is alot more Air passing though the motor now that it would have enough load to spin that little turbo?

Well updates to come !!!

even with a bigger manifold, intercooler, throttle body etc, at idle it shouldnt be sucking anymore air than before because that is all governed by the throttle body's butterfly. If the clearance was wrong on the throttle body and it was sucking too much air, then you would just have a high idle and we know rpm doesnt create boost, but load. It could idle at 4000rpm, but with no load, it wont boost.

Once you put everything back together, check the timing, then check it again, and have it set around 15degrees and get another boost gauge and see what happens. It has to be a timing issue, or its just the gauge.

An easy way to check if its running boost if you cant get another gauge, just disconnect a vacuum line (it has to be vacuum) and see if its sucking air. If it is then you have vacuum and its not running boost. If its running boost you will hear it, does it sound like it spooling??

edit: i just watched the video, i thought you were talking about hitting boost at idle, like hitting boost while it just sits there at 650rpm. Thats what happens when you skim over the post lol. Hitting boost is completle normal when you free-rev like i explained above, the amount of boost your hitting seems abit high, and it seemed like it was a bit slow, my bet is timing...

Edited April 10, 2007 by R34GTFOUR

[Cubes]

Mine only makes 5psi or so on the 2nd or 3rd hard rev. Never on the first rev, thats a RB30det with a standard size turbo.

[tomtomtuning]

Mine only makes 5psi or so on the 2nd or 3rd hard rev. Never on the first rev, thats a RB30det with a standard size turbo.

I got every thing back togetter.. but still having the boost issue.

But today was checking the TPS signal to make sure thats right.. And its not.

It reads 6.XX when closed, and like 9.XX when open.

I have a serious TPS issue...

I am still trying to work this issue out.

I ordered a Nissan Consult, and it should be here later this week.

Which should allow me to see what the TPS signal is.

If i cant fix eather problem, they will just wait till i get my standalone then.

I think if the TPS is reading that high.. that the car is sending a massive amount of fuel

Which would explain alot of stuff, like the really bad hesitation,

and the black when ever i rev it up a decent amount

[tomtomtuning]

Here are some random pic's ....

The car is on the ground now, but its still not done...

I am still working on it, so there is several things i need to do..