RB25 not making very much power

[95_240]

So my car is at a tuner and from what I can remember he said my car is only making 246 whp at 12 psi and when he bumps it up to 19 psi it is only making 275 whp. He said at 246 at 6000 rpms the curve goes flat and at 275 at 6000 rpms the hp falls off. He also said the torque is very low. He also said that he is removing more fuel than he should have to because the car is running rich at higher boost and rpms. He believes there may be a restriction in the intercooler or exhaust. This is what is done to my car:

HX35
I believe the intercooler is a 3" but he said it might be 2.5"
Stock throttlebody
3" exhaust with a Y that goes to a qtp cutout and the other side to the stock muffler
Freddy intake manifold
750cc injectors
Aeromotive Stealth fuel pump
NGK heat range 7 plugs that are new
Adaptonic E420D
No boost leaks
Stock internals

Any ideas?

[Yellow4g63]

s*** coil packs? broken turbo? broken pistons. Start checking the mechanical parts 1st.

[95_240]

New oem coilpacks, rebuilt turbo, and compression is 170 on all cylinders. I thought I might have some blowby but the tuner said it shouldn't have power that low with some blowby.

[RRRRB]

Check cam timing

[95_240]

Today we bypassed the intercooler using straight pipe and that made no difference. Removed the exhaust and got up to 290 whp. Have a q45 throttle body laying around that we are going to try. I saw the dyno graph and it's at 5000 rpms that the power stops increasing and stays at 290 until 7000 rpms but the graph isn't a straight horizontal line during this period. The graph spikes up and down a little bit. The timing is correct and it sounds really good. I don't think the throttle body will make much of a difference but I don't have any other ideas. I never had the car dynoed when it had the stock turbo on it but I always felt like it didn't have much power at higher rpms kind of like what it is doing now.

Thanks for the ideas and help so far.

[Yellow4g63]

My buddies car had a problem like that when he was stock. turned out his CAS was going out on him, He was on a PFC at the time.

[95_240]

I've always kind of suspected my cas because in the edu data on the adaptronic the trigger signals from the cas would turn red every once in a while instead of remaining green or yellow. I'm not sure if this is normal but I'll mention it to him since he's pretty experienced with my ecu.

[95_240]

Kind of a lame video. I didn't tell the tuner I was recording so I wasn't going to take a video of him without his permission. I think everything sounds good unless someone has another opinion. Don't hear any misses or anything like that.

[RRRRB]

Put a timing light on it while doing dyno pulls, compare against what it should be in the map.

[RRRRB]

sounds like there is an exhaust leak?

Are you running an external wastegate with an atomospheric dump?

[95_240]

The wastegate is plumbed back into the exhaust. I think that video was with the exhaust cutout open. I removed a portion of the exhaust and now it is running straight down pipe. We thought the exhaust might have been a restriction because it was crush bent. Removing it added about 15 hp.

As far as the wastegate goes my downpipe that was built by a shop and that didn't do a very good job. The vbands on the wastegate don't line up if I bolt the downpipe to the turbo first. I have to bolt on the wastegate and then use a little force to attach the downpipe to the turbo. I did notice last time I removed it that there was black soot that had been seeping past one of the vbands on the wastegate. I'm not sure if that was a result of the vband not being tight enough or the poor fitment of the downpipe itself. I can't remember which side of the wastegate was leaking. I won't be going back until Tuesday to try some of this stuff so I should know more by then.

[95_240]

Couple of quick questions.

Does 290 whp seem in the ballpark for 5000 rpms with this setup?

Also is it a possibility that the vct is bad? I guess when I check timing during a dyno pull that would eliminate a bad cas and vct. I'll do that tomorrow and report back.

I also have a weird problem when the car is first started it has to be revved up to 2000 rpms a few times before the alternator starts charging. It is a quest alternator that I had rebuilt. Not sure if this is related at all just disclosing.

[Carl H]

post up a dyno curve, but from what it sounds like you have a timing issue.
either the cas is dying or the map simply doesnt have enough in it.

[Carl H]

just watched the video and it sounds soggy as hell, my bet is the base timing is off or the map doesnt have much at all.

[95_240]

Here is the dyno. This time made 336 hp and 295 tq. This is on a mustang dyno.

[95_240]

Here is the VE fuel map screenshot:


And the ignition map:


I'll double check base timing when it stops raining. Wasn't able to be there last time he dynoed so I couldn't put a timing light on it during the pulls.

It was making full boost in 4th gear between 3500 and 3750 rpms when I was eyeballing it. I'll do a log when it stops raining to confirm this.

[RRRRB]

how much boost for the 336whp run?

Is boost falling off at all?

Timing seems close maybe a little high actually, you're running a couple degrees more than i was on pump gas.

[roy8532]

Blocked Cat?

[Carl H]

whats going on with the ve map, the numbers are awfully consistent and a proper ve map should have a rather large range depending on load site.

is the target lambda table set up correctly?

that much timing underboost can be dangerous depending on motor and mixture but should make more power for sure.

is the vtc active?

why is there a giant spike in the ve and the timing map?

why is your idle timing only 5*, most rb motors idle poorly with that little timing...typically i'll do 15* on a 20/25/30 and 20* on a 26.

[95_240]

Boost was 19 psi and stays pretty steady.

He said it was running rich at higher rpms and when in boost so he had to use less fuel. He wasn't sure why it was doing this but said he should be doing the opposite so I'm guessing that is why the ve isn't higher.

I'm not sure how it should be setup but I have the ecu file if anyone is interested in taking a look at it.

The vtc looks to be activated at 2000 rpms and doesn't deactivate until 8000 rpms. I talked to him about this and thought he understood that it should be deactivated below 5000 rpms. Maybe I'm reading the setup wrong though.

Yeah I don't know what's up with the giant spike and I don't know why my timing is so low. My timing light is acting up so I'll have to get another one before I can check base timing. The base map is actually set to 15 degrees and the ve is around 70-80 but my car wouldn't idle with these settings. I increased the ve to 120 just to get it to idle. I didn't mess with the idle settings because I don't really know what I'm doing. I guess instead of increasing the fuel map he lowered the timing map?

The tuner is pretty popular across the US and a prominent member on here had his RB25 tuned by him. So I'm not 100% sure if it's in the tune or if there's something going on with my engine. Before I got it tuned I tried the base map and a couple of tuned maps just to see if I could get my car to idle but they didn't work. He brought it a long way as far as driveability but it's still not where I believe it should be.

Nico won't let me attach files but here is a link to adaptronics forum. http://www.adaptronic.com.au/forum/inde ... 1#msg26521 In my last post I attached a log that can be opened in excel or megalogviewer. It also has the ecu file in an earlier post if anyone wants to look it over.

[Carl H]

vtc should be disengaged by 5k on a 25 with stock cams, bigger cams you can often extend activation and it will keep the torque up.
i'd resync timing (or at least verify it) and go from there.
the ve map still bothers me an awful lot...it shouldnt be so flat.

Heres my VE map as an example, granted different ecu and different tuning methodology but the concept is the same.

[95_240]

I got a more reliable timing gun and will double check timing tomorrow.

One thing I noticed in my log was a drop in battery voltage to around 12 volts at higher rpms. Not sure if this could be causing a problem but I'll try to figure out why it is doing that tomorrow.

[Carl H]

while there should be compensations in the ecu for the voltage drop it isnt helping.
still doesnt explain power.

[RRRRB]

how did you check for boost leaks?

How sure are you that cam timing is correct

[95_240]

I checked timing and it was right on 15 degrees. I can pull off the cam cover and verify mechanical timing tomorrow. And the vtc is definately on past 5000 rpms so I guess that could be limiting the power.

As far as boost leak testing there are two small leaks when I switched throttle bodies but in earlier runs there were no leaks prior to switching throttle bodies.

[95_240]

I've been waiting on exhaust parts before I took it back up to the tuner and I guess it's a good thing I waited. The car felt like it was getting progressively slower and then my battery light came on yesterday and my car really started acting up. Running really rich at idle and didn't feel like it had much power kind of what it was doing on the dyno only worse. Voltage was at 14 when I tested it with a multimeter while idling. Hooked up my phone and drove for about 200 yards and the voltage dropped to 11.4 and went lower with higher revs. Pulled off the alternator thinking it was bad and the power wire literally fell out of the crimp fitting. So a very poor connection was probably causing this, I hope. Taking my car back in a couple of weeks to check the tune. Would do it sooner but of course my radiator started leaking and I have to order a replacement.

[TimTurboZ]

reading people post about the CAS makes me definitely want to replace mine now. I had issues with low power for no good reason its only $200 from Raw Brokerage for my plastic top CAS.

Interested to see what happens with your car. Its always one fix after the other, money pits!!!

[95_240]

Update.

I've been doing a lot of work to my car and I finally got it back together. Now I guess I'm having problems with timing. I've been timing it by using the signal wire that feeds into the number one coil pack. All 3 of the timing lights I've used get a reading off of this and when it is set to 15 degrees the cas lines up with the bolts in the middle like most stock ones do. I decided to use a spark plug lead because I've heard this is more accurate and it is recommended in the adaptronic setup procedure. Now only one of my timing lights will pick up a signal on this setup. I have a basic innova timing light that will pick up the signal, a digital innova timing light that won't pick up a signal, and some off brand basic light that won't pick up a signal. The light that picks up a signal shows my timing to be way off. I have to advance the cas fully counterclockwise to get it to 15 degrees. I have checked mechanical timing. Both cams line up with the dots when at tdc and there are 38 teeth between the two dots. I don't know which timing method I should use since I'm getting drastically different results and the spark plug wire method results in the cas being advanced a lot. One thing I did notice is that the timing lights appear to flash at tdc and 180 degrees from tdc when I hook up to the signal wire. I don't know if this is a result of wasted spark or something else.

[Carl H]

you should not be rotating the cas to set your base timing on a standalone!
you need lock timing in the adaptronic software and set your trigger offsets to match the light, best way to do this is to slam the cas full advance and lock it down then with the motor off use the spark plug lead method and disconnect the injectors.
have some one roll the motor over till you get close to your locked value by adjusting the trigger offset then reconnect the injectors and start the car.
20* lock should start and run the car reasonably well enough to verify the trigger offsets.

also if running wasted spark (which the plug in adaptronic is) be aware that a dial back timing light will read DOUBLE what a standard light will, so compensate accordingly.

[95_240]

Ok. I did not know not to adjust the cas with a standalone but I think it is making sense now. I was locking the timing but adjusting the cas and didn't know to mess with the offset triggers. So would I set it in the method you described to 20 degrees, then adjust the trigger offset, and after that since my timing is 5 degrees at idle on the base tune then do I adjust my cas to read 5 degrees?

Thanks