Can't seem to get enough power out of built RB25DET?

[240slidekat]

hey eh? did you get my email?

[radianation]

Not going to get to do a dyno run for about two weeks. Will update the thread when I have more details. Thanks

[eh?]

You don't need to do it on a dyno. a 3rd gear pull on a *private* road will be enough...

[radianation]

It's snowing here though =)

[Cjmartz2k]

It's snowing here though =)

No ballz

[scarboroughdub]

okay first you dont have to touch the CAS and here is an "easy way to sync the timing"

1. hook up timing light2. go to the ecu set up > set timing blah blah blah3. put a value at the "fixed timing" section (i entered "10" degrees)4. check your timing with the timing light and make sure its the same value you put in under fixed timing5. if it is not then use the advance/retard buttons to get it to the same value (10 degrees).6. once you match the fixed value on the aem ems and the value on the timing light then your done.

hope this helps, im also using aem ems so if you have anymore question then feel free to ask me. i know that aem ems is a pain in the butt sometimes.

i dont know why you are still posting and not doing what he ^^^ just posted.

Set the base timing as described above, also when you go to clam the inductive clamp for the timing light, remove the #1 coil and rig up a spark plug wire between the coil and spark plug, now clamp the timing light on this spark plug wire.

This is the most accurate way.

[WhatsADSM]

i dont know why you are still posting and not doing what he ^^^ just posted.

Set the base timing as described above, also when you go to clam the inductive clamp for the timing light, remove the #1 coil and rig up a spark plug wire between the coil and spark plug, now clamp the timing light on this spark plug wire.

This is the most accurate way.

x3

What was described by slidekat is the correct way to set the timing with the AEM EMS (and most EMS have something very similar). Also just as scarboroughdub said make sure you are clamping around an actual plug wire by pulling the coil out and using a plug wire between the plug and coil.

Do that and then report back. Your timing table looks decent, at least not way far off where you would be missing tons of power or anything.

[radianation]

Somehow I missed 240slidekat's post listing the steps.

I've already done this except I set the timing to 15 degrees. I made a custom connector to get the proper wasted spark and everything.

I think the next step is to clean up the timing map with the help of the dyno. If the weather clears up I'll do a pull and log it to post here.

[WhatsADSM]

Somehow I missed 240slidekat's post listing the steps.

I've already done this except I set the timing to 15 degrees. I made a custom connector to get the proper wasted spark and everything.

I think the next step is to clean up the timing map with the help of the dyno. If the weather clears up I'll do a pull and log it to post here.

What do you mean custom connector to get the proper wastespark? The AEM EMS (At least s1 for the RB engines) is setup to always run wastespark?!

As long as you are sure that when the AEM says it is giving you 15 degrees of timing the light reads 15 degrees then you are fine. The rest is in the tune/mechanics.

Keep us posted on what you find. I am also kind of leary (as many others have mentioned) of going completely off dyno numbers. Each dyno reads slightly differently, and really should just be used to get relative numbers. I would be curious to see what 386whp actually gives you in a quarter mile ET. That is more important anyways, since we don't race dynos around anyways.

[radianation]

If you hook up to the white wire on the coilpack for an RB I think you'll get a wrong signal for the inductive pickup. Instead, I use a spark plug cable modified to go into the spark plug opening and connect to the coil pack, then put the inductive pickup on that. Worked rather well and was easy to do.

There was a writeup on the web about it and that's what I followed.
Modified by radianation at 12:53 AM 12/29/2009

[WhatsADSM]

If you hook up to the white wire on the coilpack for an RB I think you'll get a wrong signal for the inductive pickup. Instead, I use a spark plug cable modified to go into the spark plug opening and connect to the coil pack, then put the inductive pickup on that. Worked rather well and was easy to do.

There was a writeup on the web about it and that's what I followed.

Modified by radianation at 12:53 AM 12/29/2009

Ahh okay. Yup that is the correct way to check timing with an inductive light on an RB. I think it was the wastespark connector part I was confused about.

In any case sounds like you are checking it right. Using the menu that slidekat mentioned you can easily ensure that you tell the AEM to fix the timing to something like 15 degrees while you set the timing on the CAS. That is the safest way to set the cas timing.

You can also play around with the maps to give it a fixed timing value and double check what timing the AEM says it is delivering by using the parameter window and looking for ignition timing.

So yes sounds like you have the CAS set correctly, so I would continue looking. Just double checking but have you also checked for boost leaks? You sure your mechanical timing (i.e. cam/crank) timing are correct?

[gawdzilla]

that is a good way to do the base timing.

like i said earlier, your numbers are not terribly far off. the dip in your dyno is strange. perhaps there is a boost spike early followed by tapering off? also, what is the spring rate of your wg? you should be able to run slightly more than double the boost of your w/g spring.

is the w/g set up correctly (e.g. using both top and bottom ports?)

i'd say the reason for your low peak # (which again is not that far off) is your boost control and rev limit. just my opinion.

[radianation]

I've checked the pipes and the fittings and haven't noticed anything loose so I'm not sure how else to check for boost leaks without using some colored dye for air or something like that? Vacuum pressure is good in/out of boost as well.

Again, something you said has thrown me off... Your post says:

"you can easily ensure that you tell the AEM to fix the timing to something like 15 degrees while you set the timing on the CAS."

How do I set the timing on the CAS? I've set it via the AEM and I've been told I do not physically adjust the CAS itself. This comment confuses me.

Regarding the W/G -- I can't remember what spring rating we're using and I don't know 100% if it's setup correctly. I wouldn't be surprised if it still has like a 16psi spring in there or something from the initial break-in on the motor. Good point here.

[240z4u]

Bypass the boost controller, and hook the vac line directly to the wastegate. Go out and make a quick pull and see how much boost it makes. That will tell you what the spring pressure is. A 14 psi spring will get you high 20s with a boost controller. I had a 7 psi spring in mine and it wouldnt really boost consistently over 17 or so... like yours. Power also fell off on the top.. like yours.

Evan

BTW; Really glad to see your taking the initiative to fix this yourself.

[radianation]

The snow has cleared off and we have a nice day. I'm going to try and do a pull on this very long and secluded hwy on ramp near my house if I can get out of this conference call in time.

[gawdzilla]

i've never worked with the AEM, but with the PFC, you want to match the timing from your timing gun with what the PFC thinks the timing is. This is done by rotating the CAS.

For example, if your PFC is showing 15 btdc at idle, the timing gun should also show this. that way your timing maps are comparable to others. the PFC wont "know" how you set your CAS. it assumes you set your CAS correctly and adjust + or - from there.

i'm guessing this applies to the AEM too.

[radianation]

Hmm then I really need somebody with the AEM to speak up and confirm. I've heard a lot of conflicting information about this and AEM won't actually answer my questions directly =/

[radianation]

Well, I was able to get ahold of AEM directly via phone and here is what they said:

1. No need to adjust the CAS manually, although you can do it if you want.

2. You set the timing directly in the AEM EMS. So if I want a base timing of 15 degrees I set that in the box on the timing screen.

3. Then you use the timing light to see what the crank reads. If the crank is off a bit, you use the coarse and fine adjustments so that the crank reads 15 degrees (or whatever you put in the box in the AEM EMS). This is simply the offset that the AEM is using to compensate for the timing so that they are accurate.

Sounds easy enough. I don't think I set 15 degrees in that box, but I'm going to check. All I did was make sure the offset was correct so that my crank was @ 15 degrees with the timing light. BRB to let you know and post the logs.

[240slidekat]

Well, I was able to get ahold of AEM directly via phone and here is what they said:

1. No need to adjust the CAS manually, although you can do it if you want.

2. You set the timing directly in the AEM EMS. So if I want a base timing of 15 degrees I set that in the box on the timing screen.

3. Then you use the timing light to see what the crank reads. If the crank is off a bit, you use the coarse and fine adjustments so that the crank reads 15 degrees (or whatever you put in the box in the AEM EMS). This is simply the offset that the AEM is using to compensate for the timing so that they are accurate.

Sounds easy enough. I don't think I set 15 degrees in that box, but I'm going to check. All I did was make sure the offset was correct so that my crank was @ 15 degrees with the timing light. BRB to let you know and post the logs.

dude this is what i been telling you the whole time! as far as the 15 degrees, it doesnt matter what number you put in there as long as the value you put in matches the timing on the crank. if not then adjust with the coarse to match it.

[radianation]

I know you said it, and it makes sense now. But it didn't make sense at the time because the box in the AEM EMS screen said "test" so I never used that before.

I noticed that the timing was set to approximately 20 degrees BTDC.

The other thing I noticed is that the FSM says the timing should be 15 degrees BTDC @ 650 RPM. I'm at around 1,000 RPM at idle. How big of an impact will this have?

[240z4u]

I know you said it, and it makes sense now. But it didn't make sense at the time because the box in the AEM EMS screen said "test" so I never used that before.

I noticed that the timing was set to approximately 20 degrees BTDC.

The other thing I noticed is that the FSM says the timing should be 15 degrees BTDC @ 650 RPM. I'm at around 1,000 RPM at idle. How big of an impact will this have?

You have to be much more specific and clear when you are talking about this stuff. What was set to 20 degrees? The AEM or your timing when you viewed it with the timing light? If the crank says your at 15 degrees, and the AEM readout says your at 20 then your whole map is skewed.

Not sure on the idle, you should be able to look at the map and see what the timing is in that cell and double check it with your timing light on the crank pulley.

Evan

[radianation]

Ok, the AEM said 14.99 and the timing marks showed it to be at 20 degrees btdc (according to the r33 fsm). So, yes... The whole map would have been off by 5 degrees I suppose.

I fixed the timing and tried to do a pull on the on-ramp I mentioned, but my laptop died. So I went home and charged it up and then did the best I could in 3rd gear on a stretch of back road here before it got dark.

You can view my AEM LOG data for this 3rd gear "attempt" (only got to about 80mph before the road became unsafe at that speed).

I also made a realtime video of the AEM timing map display during this attempt so you can see what I would see and the log data.

AEM Log Data

Video
Modified by radianation at 3:14 PM 12/29/2009

[WhatsADSM]

As for the timing you are making this WAY harder than it needs to be.

No matter what way you do it, whether rotating the CAS or playing with the AEM coarse/fine you are simply trying to make sure that when the AEM says it is giving you X degrees, you are really getting X degrees.

Doesn't matter what your idle is, doesn't matter what the load is. You are just making sure the AEM timing value matches what is actually being output.

[radianation]

Gotcha.

I think the initial timing issue is solved then. The AEM is seeing exactly what the crank is showing.

Now for the timing map... =|

[eh?]

unfortunately those runs aren't good. I know it gets scary, but the throttle needs to be all the way down (100%) for an accurate picture.

[radianation]

Ok. I'll try again on Tuesday. I noticed a "blip" on my 2nd pull in 3rd gear. It looks like the timing map shot up to the top and it was at 12 degrees where the previous values were much higher. I had not changed the throttle when this happened.

[eh?]

Something is up with your timing. It's jumping around at idle. Actually there's a lot of jumping in the 0% throttle settings. I see a big drop in boost between 2:53.5 and 2:54 and the ensuing timing jump. What happened there? You're also too lean in boost, 20psi and 13.7afr isn't good.

[spolitte]

I can't open the file, but maybe its just me?

However, if your timing is jumping around at idle then there is a chance that the AEM is not reading the CAS wheel correctly, which is sometimes a problem with the 360 slot nissan cas wheels and aem ems, thus the reason they send you a replacement cas wheel. This usually only happens with one brand of the nissan cas discs (can't remember which brand off the top of my head) and doesn't happen with all of them of this brand (kinda hit or miss). However, if your timing in the AEM is not syncing just about perfectly then your timing will jump around a bit, and if you decide to rev the engine up the timing is going to jump around even more at high rpm, which could cause pre-det and some really big knocks (no good).

And if anyone has an idea why I can't open up either the video or the data log then please let me know ;p

Edit: Scratch that, got the AEM log to open, still having trouble with the video tho
Modified by spolitte at 6:14 PM 12/29/2009

[radianation]

Yes, I have requested the replacement disc. I believe I have the Hitachi disc. =/

The AFR used to be better before I adjusted the timing.

[flatrate]

AFR doesnt normally change much from ignition timing changes, if you continue to make pulls at anything above 12.5 AFR your asking for it 20psi on pump and 13.7AFR your lucky nothing has happened already...poor ring seal or engine condition could also be the result of your low power...