Jump to content
SAU Community

Wanted Info On Front Mount For R33

S1R33

By S1R33,
in Engines & Forced Induction

 Share

Recommended Posts

insu Rising Star

insu

Posted
Posted

I suppose however, that on a completely stock skyline, the stock intercooler would have an efficency close enough to a FMIC for the purpose of producing the power made at 'stock'. Furthermore any advantages made by lowering the charge density of the air from a FMIC would probably be outweighed by the difference in the 'lag' time taken for the turbocharger to increase the pressure in a larger area.

So in that respect Paul, I would agree with you. I wouldn't see how just adding a FMIC would increase power (unless you had other mods like exhaust, upped boost pressure etc).

S1R33 Contributor

S1R33

Posted
  • Author
Posted

I just picked up my blitz boost controller from autobarn today, f*ken whole manual is japanese, there goes the auotbarn sales talk 'it wll bolt on, just read the manual'. I ordered a Hybrid front mount intercooler kit through them yesterday as well, got if for $890 inc freight to Darwin, not too bad, could have got it cheaper but i get a local replacement warranty etc. MODS are coming slowly

locosam Contributor

locosam

Posted
Posted

When i installed my front mount, the biggest thing i noticed was the lack of throttle response. Running the same boost i thought that the car was a little slower overall.

Turning up the boost sorta overcame that problem, but throttle response wasnt there. When boost hit though, it felt faster (since i was running more boost), but from my experience with a FMIC, ive come to the conclusion that a fmic is a support part to allow you to get more power.

I still need tuning though so maybe my opinion will change after that.

So pretty much what paulr33 said is spot on.

What youll get is more lag, less throttle response and worse fuel economy, but you get the potential to make more power in the end.

my fmic is a greddy v-spl

grigor Rising Star

grigor

Posted
Posted

Physics hey? Boyles Law, Charles’s Law etc.

P1V1/T1=P2V2/T2

I’ll borrow some numbers from FMIC tests for a RS500 and pick a boost of 15psi.

Turbo air temp was 135deg C. (408 deg absolute)

After the cooler the air temp is 35deg C. (308 deg absolute)

So the turbo pumps 15psi x V1 at 408 deg absolute.

After the cooler we have either 0.75V1 at 15psi or V1 at 11.3psi.

Sure there is air flow resistance in the pipework and heat soak for a sustained load, but the numbers demonstrate you get more denser air.

Most errors happen in wastegate pressure readings.

An Rb20 takes the wastegate pressure straight from the compressor housing so it doesn’t know what is happening in the plenum. It will spool up fractionally faster but now there is a lot more volume to fill so it’s a bit laggy.

Once the initial surge has levelled out, the plenum pressure will be lower than normal, but it will be filled with denser air so the net result is similar power, with a nice anti-detonation safety margin.

The Rb25 takes its wastegate pressure after the cooler, so you’ll get more air in the plenum due to the increase in air density. Again it will spool up slightly faster and it will have some lag, the plenum pressure will read same as before but it will now have a more dense air charge. The turbo has eaten more air and the AFM is out of sync with the parameters set up by Nissan.

Without altering the tune via a PFC etc, the AFM will sense the larger air flows and start to dump in fuel. Stop/start conditions are the worst as it’s continually fuelling for unrealistic air flows, the black-bumper syndrome.

If you add some other factors like a cold evening and no air temp compensation, I’m sure that’s why so many slightly modded Rb25’s experience the R&R which ends in the Ignition/Fuel cut and the poor old coil-packs cop the blame.

Regards.

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
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • 04-LOOX
      R34 GTR Vspec Garage Sale - All must go!

      By 04-LOOX · Posted

      Hi, is the HKS  Tower Bar still available ? negotiable ? 🤔
    • Duncan
      Duncan's V37.......race car?

      By Duncan · Posted

      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.
    • Duncan
      Duncan's V37.......race car?

      By Duncan · Posted

      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.      
    • Duncan
      Duncan's V37.......race car?

      By Duncan · Posted

      Onto the android unit. You need to remove the top screen because there is a daughterboard to put inside the case. Each side vent pops out from clips; start at the bottom and carefully remove upwards (use a trim remover tool to avoid breaking anything). Then the lower screen and controls come out, 4 screws, a couple of clips (including 3 flimsy ones at the top) and 3 plugs on the rear. Then the upper screen, 4 screws and a bunch of plugs and she is out. From there, remove the mounting brackets (2 screws each), 4 screws on the rear, 2 screws top and bottom and 3 screws holding in the small plates on each side. When you remove the back cover (tight fit), watch out for the power cable for the fan, I removed it so I could put the back aside. The mainboard is held in by 1 screw in the middle, 1 aerial at the top and 3 ribbon cables. If you've ever done any laptop stuff the ribbon cables are OK to work with, just pop up the retainer and they slide out. If you are not familiar just grab a 12 year old from an iphone factory, they will know how it works The case should now look like this:
    • Duncan
      Duncan's V37.......race car?

      By Duncan · Posted

      Switching the console was tricky. First there were 6 screws to remove, and also the little adapter loom and its screws had to come out. Also don't forget to remove the 2 screws holding the central locking receiver. Then there are 4 clips on either side....these were very tight in this case and needed careful persuading with a long flat screw driver....some force required but not enough to break them...this was probably the fiddliest part of the whole job. In my case I needed both the wiring loom and the central locking receiver module to swap across to the new one. That was it for the console, so "assembly is the reverse of disassembly"
×
×
  • Create New...