Jump to content
SAU Community

Recommended Posts

  • Replies 41
  • Created
  • Last Reply

Top Posters In This Topic

Turn the boost up.15psi is nothing for that turbo.But i wouldnt be doing it till you get some Ks up on the motor.

At 15psi this should make at least 300rwkw, a T78 can make 300rwkw at 15psi. Boost is definately not the problem.

In saying that, maybe is a high pressure boost leak? Can you check the plumbing? Use a compressor, and pressurise the system. Go right up to 30psi and see if you can hear anything. You'll need to fabricate some sort of inlet that you can hook the compressor up to.

Compression test.... leak down test??.... no fkn idea what it means but my cuz said it might help since you did some head work.

8:1-8.5:1 compression: 150-170 psi per cylinder

8.5:1~9.5:1 compression: 170-210 psi per cylinder

9.5:1~11:1 compression: 210-275 psi per cylinder

also make sure there isnt more than +-20 psi difference between each cylinder

also he suggested pressure testing the intercooler system for leaks....

rofl, who told you this? A Brand new RB25 makes 172psi and its comp ratio is 9:1. Its definately not accurate. What if the engine is worn?

Also, there shouldn't be any more than 5psi variance between the cylinders. 20psi? haha. If my engine had even 15psi variance, I'll pull it down..

seen a 3" exhaust make 893rwhp, so that wont be an issue

You're right, a 3" ex should flow the numbers no probs BUT if the cat substrate has collapsed, coked up etc (same for the muffler/s) there's a good chance it won't. Spend the time, drop the ex in front of the cat & at least then you'll know one way or the other for sure. Assumptions can very easily lead to f**k-ups & waste a whole lotta time

You're right, a 3" ex should flow the numbers no probs BUT if the cat substrate has collapsed, coked up etc (same for the muffler/s) there's a good chance it won't. Spend the time, drop the ex in front of the cat & at least then you'll know one way or the other for sure. Assumptions can very easily lead to f**k-ups & waste a whole lotta time

yeah soory, should said i was sorta referring in general to the flow of the exhaust, not allowing for blockages

whilst im getting specs on cams we thought we'd throw in sum standard rb25det ones

to see i that would make a difference..

tried to start it tonite and engine had nothing, sounded like no compression..

motor would spin but not normal sounding at all ?????

mayb cams not opening valves ??

will try get pics up...

hey carl, how u been mate? been alrite jus busy with work and over this car...

cant remember exactly what rpm will get the dyno print out, but it jus seems to go almost straight up to 245rwkw then flatten across, prob around 4500rpm not to sure tho..

also trying to figure out the problem on th lower boost, but might try 20psi and see what happens

Usually it shouldn't be an issue going from a large lift cam to a small lift cam but did you bleed down the lifters before you put the cams in?

if it has solid lifters and fitting the standard cams which may have a larger base circle might be causing the valves to stay open slightly making the cylinders lose compression.. as cube said, check the clearence.

If the head has been converted to solids, and now has hydraulic cams, the the opening ramps designed to close the lifter will be opening the valve and therefore the duration of the valve lift will be huge, causing it to bleed off compression.

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

    • Can I suggest you try EBC directly again and link them to as many competitor catalogues as you can to show their listing is incorrect, eg https://dba.com.au/product/front-4000-series-hd-brake-rotor-dba42304/ If you have access to an R33 GTST VIN and your VIN, you could also use a Nissan Parts lookup like Amayama to show them the part number is different between 33 GTST and 34 GTT which may get their attention
    • So i got reply from EBC and they just this site where you can clearly see those 296mm fronts on R34 GTT. I send them photos and "quotes" that 296mm are not for 34 GTT and they are too small. But it will be very hard to return them cuz nobody here knows 100% and they just copy those EBC catalogue :-D https://ebcbrakesdirect.com/automotive/nissan/skyline-r34
    • Hi, is the HKS  Tower Bar still available ? negotiable ? 馃
    • From there, it is really just test and assemble. Plug the adapter cables from the unit into the back of the screen, then the other side to the car harness. Don't forget all the other plugs too! Run the cables behind the unit and screw it back into place (4 screws) and you should now have 3 cables to run from the top screen to the android unit. I ran them along the DS of the other AV units in the gap between their backets and the console, and used some corrugated tubing on the sharp edges of the bracket so the wires were safe. Plug the centre console and lower screen in temporarily and turn the car to ACC, the AV should fire up as normal. Hold the back button for 3 sec and Android should appear on the top screen. You need to set the input to Aux for audio (more on that later). I put the unit under the AC duct in the centre console, with the wifi antenna on top of the AC duct near the shifter, the bluetooth antenna on the AC duct under the centre console The GPS unit on top of the DS to AC duct; they all seem to work OK there are are out of the way. Neat cable routing is a pain. For the drive recorder I mounted it near the rear view mirror and run the cable in the headlining, across the a pillar and then down the inside of the a pillar seal to the DS lower dash. From there it goes across and to one USB input for the unit. The second USB input is attached to the ECUtec OBD dongle and the 3rd goes to the USB bulkhead connected I added in the centre console. This is how the centre console looks "tidied" up Note I didn't install the provided speaker, didn't use the 2.5mm IPod in line or the piggyback loom for the Ipod or change any DIP switches; they seem to only be required if you need to use the Ipod input rather than the AUX input. That's it, install done, I'll follow up with a separate post on how the unit works, but in summary it retains all factory functions and inputs (so I still use my phone to the car for calls), reverse still works like factory etc.
    • Place the new daughterboard in the case and mount it using the 3 small black rivets provided, and reconnect the 3 factory ribbon cables to the new board Then, use the 3 piggyback cables from the daughterboard into the factory board on top (there are stand offs in the case to keep them apart. and remember to reconnect the antenna and rear cover fan wires. 1 screw to hold the motherboard in place. Before closing the case, make a hole in the sticker covering a hole in the case and run the cable for the android unit into the plug there. The video forgot this step, so did I, so will you probably. Then redo the 4 screws on back, 2 each top and bottom, 3 each side and put the 2 brackets back on.....all ready to go and not that tricky really.      
  • Create New...