Jump to content
SAU Community

Recommended Posts

I got the idea today to modify the stock actuator to hold more pressure on the wastegate flap. I want to see if it holds boost better.

A simple spring mounted to the shaft did the trick.

Without spring, 14psi cracked the flap.

With spring, 19-20. Should do the job but can I swap it into the car? Bloody tight down there.

post-63525-1285505108_thumb.jpg

Link to comment
https://www.sau.com.au/forums/topic/338266-i-cant-hold-boost/
Share on other sites

what metal is the spring made of?

exposing steels to temps over 200°c can alter the internal structure of the metal and will affect the "strength" of the spring

Im sure it will be fine, its a fair way from the exhaust housing and plenty of room for a sheild. Worst case it fails giving me lower boost anyway, as im map sensored it should adjust the mixtures with no issues.

  • 4 weeks later...
Havent installed it yet, because its a PITA to get down there. Next time the intake is off...

lol i think you should do it on wednesday when i come by. :)

i could help you as well if you like?.. maybe hold a light? im gonna get hold of a resistor tomorrow as well.. give me a call when your free.

lol i think you should do it on wednesday when i come by. :down:

i could help you as well if you like?.. maybe hold a light? im gonna get hold of a resistor tomorrow as well.. give me a call when your free.

Sounds good, I need to fit the replacement rear springs too, I will give you a hand between swigs. :P

Ghetto mods to the torque converter lockup, Niiice... lol.

whats the torque converter mod??? i might need it as mine is fooked :D

Cant tell you all my sercrets. :)

Its just cutting the torque converter lockup solenoid wire at the TCM and running it through a resistor to simulate the solenoid load. (so the trans ecu doesnt fault)

This will disable the lockup completely and allow the cooling circuit to remain on also. (they are both part of the same solenoid) Between that and a shift kit, the box should be fine, providing you have the nissan fluid in there...

I got the idea today to modify the stock actuator to hold more pressure on the wastegate flap. I want to see if it holds boost better.

A simple spring mounted to the shaft did the trick.

Without spring, 14psi cracked the flap.

With spring, 19-20. Should do the job but can I swap it into the car? Bloody tight down there.

Cant you modify a stronger actuator to fit?

Cant you modify a stronger actuator to fit?

Its a weird one, I would need to make a new shaft and stuff around. I will probably be upgrading engines in 6 months with a GT35 so no point buying a $100 actuator and butchering it to fit, its only a stiffer spring anyway.

This will work out free and easy to do, and if it can hold the boost a bit longer it will be worth the small effort.

yeah just looking at the pic it is a weird one, also noticed the date, and last i spoke to you i think you were already holding 20psi so guess i should get with the times hey... :)

No, its still not holding, the 300kw run was at 17 psi, I would obviously like to hold 20psi flat line at least with the ethanol, not sure the engine can hold that though, will have to wait and see. :D

Cant tell you all my sercrets. :P

Its just cutting the torque converter lockup solenoid wire at the TCM and running it through a resistor to simulate the solenoid load. (so the trans ecu doesnt fault)

This will disable the lockup completely and allow the cooling circuit to remain on also. (they are both part of the same solenoid) Between that and a shift kit, the box should be fine, providing you have the nissan fluid in there...

hmm, this sounds good. I could setup a switch to enable the lockup circuit again for when im highway driving (like going to melbourne for my tune)

No, its still not holding, the 300kw run was at 17 psi, I would obviously like to hold 20psi flat line at least with the ethanol, not sure the engine can hold that though, will have to wait and see. :P

are you using the factory boost solenoid?

do you have an EBC? if not, get one!

are you using the factory boost solenoid?

do you have an EBC? if not, get one!

Blitz spec R, should normally do the job but im guessing the flap is blowing open under the pressure in the manifold. We only have a low pressure actuator due to the "low boost" setting at cold start.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • I get that taking off the head is best but that's a bit much for "just" valve seals. I was just under the impression that one would be able to rotate to TDC and be able to temporarily drop the valve without losing it and effectively having to remove the head to then recover it. I never knew people actually pushed rope into the cylinder to do valve seals hahaha So just to confirm, just going to TDC will not work? In that case I know when I do valve seals I'll maybe just remove the head and do some other things while I'm there, or just wait until I do an engine build.
    • The old approach was to fill the cylinder/chamber with a length of rope pushed in through the sparkplug hole. The new approach is to connect compressed air to the sparkplug hole and fill it with enough pressure to push the valves up. Doing either of these things with the head on and the engine in the car is a lot less pleasant than doing it properly.
    • Can't you put the pistons to TDC and then do the valve seals? Or will the drop down too far to pull them back up?
    • One thing I can tell you is, do it properly the first time. If you encounter unexpected problems just let the car sit for a week or two if you have to get some other parts or figure stuff out.  I'd have said go and use as many OEM parts as possible but since you want to change the turbo later on a custom kit is probably the better choice. Since I have no experience with RB25 just compare parts diagrams and images before buying a line kit and it should be easy to see if it has everything you need. Amayama has very good parts diagrams and part number lists, that is what I used a bunch to figure out what I might need. And don't forget to plan ahead and possibly renew other stuff that's easy to get to while you're in there doing the turbo lines. Happy wrenching
    • Update 4:   Hi all, good news. Engine is running and all the gaskets and seals seem to be working as intended. No leaks so far, even the JB Weld seems to hold. I flushed out the old coolant a few times and put in fresh coolant, not Nissan stuff, I decided to try the Ravenol Protect FL22, they claim it works for a wide variety of JDM cars and the opinions on it by some people were pretty good. And it has the nice poison green color! And man am I glad I bought a coolant system tester earlier this year, vacuum filling works wonders on this engine. I can definitely recommend this to anyone still doing it the old school way. All you need is compressed air supply. Will have to do a small test drive as soon as I can, I removed the gauge cluster again as the tacho needle was still bouncing around a bit but it was much better than before already.  I also found some cracks on all 4 tires inner and outer sidewalls. Apparently these tires should 't be parked on for extended periods or be kept under 0 degrees during storage, which I did not know. Clearly the previous owner didn't look into those details either, he probably bought them just cause they are cool semi-slicks. I'm just wondering how tf I am supposed to reach 30-80 degree tire temperatures on the public road consistenly, these tires were never going to work for my use case. I'll probably order Continental SportContact7 ones as these are the best allround summer tire available right now and I don't think I'll need anything crazier for now. Do let me know if you have experience with various tires and which ones you recommend.
×
×
  • Create New...