Losing boost at 6400rpm. Help!

[jdub]

I'm still not too confident in that WG spring.

 

[IJ.]

J: For the no exhaust test light throttle to say 5500 in 3rd then nail it and see how it reacts.

a) This "should" show if it's still dropping boost after 6400 to be another issue but if it boosts to boost cut we might have fond the problem.

As I said I'm running out of ideas here.
(Do you run adjustable cam pullies?)

 

[jdub]

Pretty sure he does Ian...if you remember, the previous motor blew due to agressive cam timing. I asked this earlier, but never got a complete answer:

http://www.supramania.com/forums/showpost.php?p=1117303&postcount=45

 

[driftking786]

since your losing boost:.....lets make a check list,some of the list might be repeated

• inter cooler
• pipes
• turbo housing
• manifold
• gaskets
• hoses
• welds
• dyno it once more and get a couple guys that know these motors to look around while booosting
• boost controller
• coil pack?
• spark plugs?
• ignitor

if i remember anything else i will edit!

 

[suprahero]

Well if you're WG is working right it should not overboost at all. With your set up right now it may very well. Nothing you can do but try it and see what happens.

Have you taken off the pipe that goes to the IC core from the turbo to make sure you do not have any obstructions?

Jeremy

I replaced every intercooler pipe with a brand new one as well as couplings and tbolt clamps, so I know it's not that. Thanks though.

I'm still not too confident in that WG spring.

It could be a bad spring John, but It just seems unlikely that two different wastegates have the exact same datalogs........:dunno:

J: For the no exhaust test light throttle to say 5500 in 3rd then nail it and see how it reacts.

a) This "should" show if it's still dropping boost after 6400 to be another issue but if it boosts to boost cut we might have fond the problem.

As I said I'm running out of ideas here.
(Do you run adjustable cam pullies?)

I was going to try it this evening Ian, but when I jacked up the car to disconnect the pipes, I found that my right front tire is FTL. It has wire showing through all the way around the inside of it. The tread is all even, but the tire has shot it's wad. I dont' really want to be doing 100mph on it. I know, I'm a chicken shit, but call me crazy..........:aigo:

since your losing boost:.....lets make a check list,some of the list might be repeated

• inter cooler*
• pipes*
• turbo housing *
• manifold * new manifold from Drewgo
• gaskets*
• hoses* all brand new
• welds* they look perfect
• dyno it once more and get a couple guys that know these motors to look around while booosting* I looked closely and also had another supra guy there as well and we couldn't find anything.
• boost controller* does the same thing with it on or off
• coil pack? * Coil packs have less than 3500miles on them
• spark plugs?* less than 500miles on them
• ignitor stock ignitor

if i remember anything else i will edit!

 

[suprahero]

Pretty sure he does Ian...if you remember, the previous motor blew due to agressive cam timing. I asked this earlier, but never got a complete answer:

http://www.supramania.com/forums/showpost.php?p=1117303&postcount=45

I've thought about this all day for some reason so I checked it when I got home. I have my cams set to straight up for some reason. I degree'd them before I put my motor in and they degree'd to exhaust -10 and intake -5.......I don't remember changing them back to straight up, but that's where they're at.
I also don't believe the cams is what caused my other motor to blow. I'm pretty sure it was the high compression along with 18psi on pump gas. I had a stock 1jz gasket on my car at the time and with the 2.0mm that's on there now, my compression is only 8.67 :1.......the stock hg is only 1.0mm I think so my compression would have been much higher. I also found out later that my timing was fine, but my static timing when I set it on the stinger was off by five degrees, which didn't help anything..........:aigo:

 

[IJ.]

J: Check the pully bolts.....

If they're moving it might explain a lot.

 

[suprahero]

J: Check the pully bolts.....

If they're moving it might explain a lot.

They were both tight Ian..........I just don't remember moving them back. I do remember having a tough time getting it to start after I degreed them though so I may have moved them to straight up then just to get it running with plans of moving them back later. I swear I'm not an addict, but I think some of my brain cells are MIA.

 

[IJ.]

Humour me check em with a torque wrench J
(I actually loctite mine as well once set)

 

[suprahero]

If it doesn't rain here all day tomorrow then I'm going to move them to where my 1jz ran it's best unless this is a bad idea. I dyno'd the 1j and adjusted the cam gears and it made the best power without sacrificing spool up @ -8 exaust and +3 intake........when I degreed them though it was -10 and -5. It was hard to degree them though because the cam lobes were in the way of the retainers. I checked both sides twice though and came up with the same thing. Maybe I'll put the exhaust on -8 and leave the intake on 0 instead of going the opposite way from where the degreeing said to put it.

 

[tissimo]

When you switched manifolds this startted happening right?

 

[jdub]

If I remember correctly, on the previous build you had the cams at E+8/I-4. The valve centers are pretty wide here (not much overlap) and would run the cylinder compression up quite high. I was thinking that combined with your previous timing map is what made you go lean.

On this issue, I'm thinking you might have too much overlap and getting too much flow through the head, making boost fall off.

 

[suprahero]

When you switched manifolds this startted happening right?

Justin, I'll have to look back at my build and see if I had this on my 1jz. I honestly can't remember if I did or not.

If I remember correctly, on the previous build you had the cams at E+8/I-4. The valve centers are pretty wide here (not much overlap) and would run the cylinder compression up quite high. I was thinking that combined with your previous timing map is what made you go lean.

On this issue, I'm thinking you might have too much overlap and getting too much flow through the head, making boost fall off.

John, I'm positive that my exhaust was retarded eight degrees and the intake was advanced three or four degrees.

 

[suprahero]

Justin, I had the Drewgo when I went to the Texas meet and I wasn't having this problem then.

 

[jdub]

John, I'm positive that my exhaust was retarded eight degrees and the intake was advanced three or four degrees.

http://www.supramania.com/forums/showpost.php?p=976492&postcount=672

The cam are set as follows. Exhaust +8 degrees and the intake is -4 degrees.

The car has NEVER ran lean under boost. It has ran lean under normal driving before but this was after the fact. I ran it home lean on purpose to keep as much smoke as possible from exiting my exhaust so the people behind me could see. I was told it would be fine as long as it wasn't lean under boost. The person that told me this can chime in if he wants too.......or not.

Red, the motor had roughly five hundred miles on it when it started smoking, but it was very little smoking at first. It wasn't until we got past Louisiana that it started smoking horribly.

What would the AFR's need to get to, to detonate the engine like it did?

 

[kwnate]

I'm stealing your boost, I need more.

 

[ForcedTorque]

Jay you should never argue with John. He knows more about these cars than you and I will ever learn. Hell, he can even change his own oil. You were positive about something on your own car, and he beat you with your own damn words.

 

[suprahero]

I'm stealing your boost, I need more.

Please give it back......I don't make 800rwhp............:cry:

Jay you should never argue with John. He knows more about these cars than you and I will ever learn. Hell, he can even change his own oil. You were positive about something on your own car, and he beat you with your own damn words.

Scott, I had to call Blake at the dyno shop to verify what I thought was right. It ends up I'm not. My exhaust cams were +8 and the intake was -4.....I'm going to try and adjust them some tomorrow and do a pull to see if it effects the boost any. I doubt it will, but we'll soon see. I do know that the cams were +8 and -4 when I dyno'd before the Texas meet, and that is the only thing I can think of that is different with these setups. Wish me luck.

John......I bow down to your greatness............:bowdown::bowdown:

 

[jdub]

LOL...just making sure Jay
(had me thinking I was experiencing a senior moment)

I'm with Ian...running out of things to check.
If you do change the cam timing, don't go as far as above. Give E+2/I-1 a try and see if it makes a difference...you can check the cam pulley bolts too.

Don't forget this:

J: For the no exhaust test light throttle to say 5500 in 3rd then nail it and see how it reacts.

a) This "should" show if it's still dropping boost after 6400 to be another issue but if it boosts to boost cut we might have fond the problem.

As I said I'm running out of ideas here.
(Do you run adjustable cam pullies?)

 

[suprahero]

Should I do the no "no exhaust" run with my AVC-R or just wastegate?