Losing boost at 6400rpm. Help!
- Thread starter suprahero
- Start date
suprahero;1165417 said:Here's what my car looks like...............AGAIN!!!!!!!
Enough green in that picture to make it look 7M. Good thing it's all in the correct places.
suprahero;1165412 said:
Thanks for the link Jay. I haven't looked yet, but going there now. Is that the 2 MR2's that are featured in the latest street&tuner magazine I picked up last week? I haven't read the story yet, but the yellow one has gull wing doors, and a pretty hot model or owner standing with it. The other one is Red. They are both really nice cars.
I've been waiting for the answer to this for almost as long as you have Jay. But I'm gonna be pissed if you fix it right after I left your house. I believe you would have taken that green MKIV if he hadn't done a ricer start on you, and you could have stayed in it.
***EDIT*** Huxracing is 215 miles from me. I believe it may be worth the drive. Thanks Jay/Patrick
***EDIT*** Huxracing is 215 miles from me. I believe it may be worth the drive. Thanks Jay/Patrick
Tire Shredder;1166110 said:
It's still going to light off in the turbine housing Steve, just won't be making it's true HP potential.
i'm glad you found your problem. i found mine too, its the 7m, so, i'm replacing it with a 2jz.
^OUCH!!!
Update
I took head to my machinist. He measured the seat pressure, and it was at 70#, but the specs call for 80#.
The height was 1.345, but it should have been 1.325. I'm sure this is becasue the 2jz valves are longer than the 1jz valves. He's got a .030 shim he's going to add which should bring the seat pressure up to the 80#. I know the height is going to be off a little bit, but I want the seat pressure to be as much as possible. If this doesn't fix my problem then I'm going to park it for a while so I can save up and buy some oversized valves and redo it one last time. Thanks.
Update
I took head to my machinist. He measured the seat pressure, and it was at 70#, but the specs call for 80#.
The height was 1.345, but it should have been 1.325. I'm sure this is becasue the 2jz valves are longer than the 1jz valves. He's got a .030 shim he's going to add which should bring the seat pressure up to the 80#. I know the height is going to be off a little bit, but I want the seat pressure to be as much as possible. If this doesn't fix my problem then I'm going to park it for a while so I can save up and buy some oversized valves and redo it one last time. Thanks.
The machinist can't adjust the valve stem length to bring the seat pressure to spec?
70# of set pressure *should* be more than enough to keep the valves from floating at those boost pressures.
70# of set pressure *should* be more than enough to keep the valves from floating at those boost pressures.
He's adding the shim's John and then he's going to see what the height is. He's also going to recheck the seat pressure at the new height and see how close it is. If this doesn't work then I'm going to park the car until I can buy some larger valves and have it all redone. I don't have the money right now, but I'm hoping this works. I'll let you know as soon as I get it back from him and reinstalled.
70 "shouldn't" be blowing off the seats but the 2J valves have a lot of area so maybe.
I run 90>95 here on +1mm 7M valves.
I run 90>95 here on +1mm 7M valves.
buckshotglass
I love all your sounds.
buckshotglass
I love all your sounds.
suprahero;1168577 said:
Jay there's a 3000 post pipe dream for this type nonsense. Can you please update the blue car in here today
No update available Scott. As usual, Jeff Watson has screwed me over. I should have had my gaskets by now.
My machinist had to order some new shims for the head also. They're not valve shims, thir the ones that will go under the seat for the added seat pressure. I should have the head back by wednesday or thursday and I"ll put it back together..........again.
My machinist had to order some new shims for the head also. They're not valve shims, thir the ones that will go under the seat for the added seat pressure. I should have the head back by wednesday or thursday and I"ll put it back together..........again.
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How has Jeff screwed you over, if the machinist is still ordering parts? I agree that it should be there by now, but it doesn't sound like you are ready for it yet.
On a side note.......I may be trading my project 240sx for a SR20 NX2000 today, so I was searching for pictures to show my son. The best looking one I could find appeared to have your exact blue paint with matching moldings. It looked almost like a little trinket you could put out in front of your car at a car show.
On a side note.......I may be trading my project 240sx for a SR20 NX2000 today, so I was searching for pictures to show my son. The best looking one I could find appeared to have your exact blue paint with matching moldings. It looked almost like a little trinket you could put out in front of your car at a car show.
jdub;1167170 said:
You cant change the seat pressure by adjusting the valve stem length. The keeper is locked into place at the same location. Unless you cut the valve in half, remove some material and weld it back together or add material to the valve seat/face you wont compress the spring any more.
Your seat pressure may have been decreased if you had the valves or seats cut down because it would increase the distance of your keeper/retainer from the spring seat.
The machinist is placing shims under the seat of the spring in order to bring the pressure into specification. Thats really the only way to do it after the seats have been cut.
Good find and I really hope this helps you out Jay, but I sincerely dont think that this will fix your problem.