Jump to content
SAU Community

Gtr cam timing for mid range torque

pnblight

By pnblight,
in Engines & Forced Induction

 Share

Recommended Posts

rev210 Grand Master

rev210

Posted
Posted

Good work!

Although some aftermarket camshafts tend to work well in the '0' position, this position was arrived at by the manufacturer according to a specific engine base. If the engine/turbo combination you run differs greatly from the manufacturers test base it makes sense that a different camshaft timing may be required, as is often the case. If it were possible to make RB26 camshafts easily in Australia I'm sure an even better set of cams could be purpose made for that engine of yours given the amount of advance on the exhaust side of things.

What about the specs on those turbo's mate? (I think there is a line of GTR owners waiting to know).

Emre Proficient

Emre

Posted
Posted

rev210,

He specified them as Garrett 320hp turbos, Ray Hall special or AVO special etc.

I don't understand advancing the intake 10 degrees and the exhaust 8 degrees either. All that would do is to move the power band considerably I would've thought. I am thinking they jumped the cam timing a few teeth during the install and corrected it with the adjustable pulleys.

pnblight Mentor

pnblight

Posted
  • Author
Posted

hah guys,

first question differently didnt jump a tooth as that is like about 25deg of crank angle or something we check it twice.

and the urban mith about rb20 resolution is nonsence as im an instrument tech and the rb20 has better resolution than the z32 due to the smaller scale over which they operate( they plug straight in and are half the cost )(i got my 2 for $300)

and i dont clam to be the duck nuts tuner but we just spent the time and that is wot i credit most of the results to cos we nearly stopped a couple of time once at 465hp and again 485hp we though we would just try a few more thing while we were there and lucky for us it was worth the exact time

and power band is set by duration of cams and there over lap not there angle of advances

Guest two.06l

Guest two.06l

Posted
Posted
WWWOW... 388Kw at the rears on stock internals, and only pushing 18psi on pump fuel... Is that right? I couldn't believe it when I read this thread, I thought that could only happen in WA, and then I saw you were from WA, and I wasn't supprised... Well Done!

Just one thing, Stacey who has the R32 with forged Internals, full HKS Kit GT2530's, dumps manifolds etc etc.. makes 390kw at 25psi on pump fuel ~I think... I mean your result is definately impressive but nonetheless not suprising from WA those tuners have magic up there sleeves with dyno tuning GTR especially with RB20 AFM I never thought they were capable of that sort of resolution.. Obviously Stacey's R32 GTR has some big problems when comes to tuning :D

No problems with Staceys tune at all. She has this tuned for max torque not power, have not driven a gtr that can smoke all fours at will like her car does. Max low down and mid range torque i'd have anyday. While the car with max power is still trying to make boost, the car with the low down grunt is gone, long gone. Max power does not always equate to max performance on the strip. Her 60' times and launch are testament to this theory(best is 1.690) not bad for a girl huh.

Sydneykid Grand Master

Sydneykid

Posted
Posted
first question differently didnt jump a tooth as that is like about 25deg of crank angle or something we check it twice.

There are 48 teeth on RB camshaft pulleys, meaning 7.5 degrees per tooth of camshaft rotation. So that's 15 degrees of crankshaft rotation. One tooth out would turn the 8 degrees advanced into 7 degrees retarded. Possible.... :rofl:

  • 1 month later...
pnblight Mentor

pnblight

Posted
  • Author
Posted

Just to let you guys know i took this car to drag wars in perth and ran a 11.33sec 125mph pass 1.75 60 footer with major traction problems. So i think most people would agree that that sort of mph reading with a car that hooked up (ie good rubber) could go very close to maybe break into the 10 sec bracket. Story to be continued

this is the run

http://www.antilag.com/videos/dragwars04/w...aidwin32gtr.avi

you may need to download this to view

http://www.antilag.com/videos/xvid_video_codec.exe

Gav Mentor

Gav

Posted
Posted

Peter

congrats - nice result and confirms the dyno graph results quite well I think.

Nice to see some good results using something other than the usual HKS 25/30s that everyone seems to be bolting on these days. Just out of interest, what made you go the Garrets? Price, advice or both?

pnblight Mentor

pnblight

Posted
  • Author
Posted

Well i had to replace the turbos very early(because of failure at very low psi mind you) in when i bought the gtr and i was still learning about the different combination had seen the bolt in ball bearing replacement by garret and i had to keep them as close to std unit as possible but did want to put ceramic wheels back in and cos my claim went to court as i had only had the car a couple of weeks from a dealer. i had a win with the dealer having to pay for the replacement turbo and i paid for the other as the orginal was steel functional.

So it was not exactly 100% by choice but i couldn't be happier.

Gav do you think i've gone the right way with the combination.

Gav Mentor

Gav

Posted
Posted
Well i had to replace the turbos very early(because of failure at very low psi mind you) in when i bought the gtr and i was still learning about the different combination had seen the bolt in ball bearing replacement by garret and i had to keep them as close to std unit as possible but did want to put ceramic wheels back in and cos my claim went to court as i had only had the car a couple of weeks from a dealer. i had a win with the dealer having to pay for the replacement turbo and i paid for the other as the orginal was steel functional.

So it was not exactly 100% by choice but i couldn't be happier.

Gav do you think i've gone the right way with the combination.

Pete - I reckon' ya got the balance for a good street/track GTR just about spot on there mate!

As previously stated by others, cracking a 10s quarter isn't outside the realms of possibility with some Nittos bolted and with the broad midrange you'd have a ball around a track as well. Living so close to Collie, I guess you've been around that track a few times?

On the street, you must be loving handing it out to the all the "knuckle dragger" V8s in Bunno!

Hope to catch up one day when I finally get back to Perth.

pnblight Mentor

pnblight

Posted
  • Author
Posted

Yeah Gav , the car is a pleasure on the road cos it pulls from so low down (pulls off the motor from 3000rpm and hits full boost by 4000rpm) and yes i have been seen at collie sprint circuit more than once hehe and this is more wot the car was built for and where my passion is, drag has been a little side destraction.

The future for this gtr i think is now more on reliability issue (not that is ever like me down) like N1 oil pump, oil cooler, sump extension, posible bigger cooler and maybe even some forged pistons etc.

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

    • Kinkstaah
      Mistakes were made, my R34 Story

      By Kinkstaah · Posted

      God damnit. The only option I actually have in the software is the one that is screenshotted. I am glad that I at least got it right... for those two points. Would it actually change anything if I chose/used 80C and 120C as the two points instead? My brain wants to imagine the formula put into HPtuners would be the same equation, otherwise none of this makes sense to me, unless: 1) The formula you put into VCM Scanner/HPTuners is always linear 2) The two points/input pairs are only arbitrary to choose (as the documentation implies) IF the actual scaling of the sensor is linear. then 3) If the scaling is not linear, the two points you choose matter a great deal, because the formula will draw a line between those two points only.
    • GTSBoy
      Mistakes were made, my R34 Story

      By GTSBoy · Posted

      Nah, that is hella wrong. If I do a simple linear between 150°C (0.407v) and 50°C (2.98v) I get the formula Temperature = -38.8651*voltage + 165.8181 It is perfectly correct at 50 and 150, but it is as much as 20° out in the region of 110°C, because the actual data is significantly non-linear there. It is no more than 4° out down at the lowest temperatures, but is is seriously shit almost everywhere. I cannot believe that the instruction is to do a 2 point linear fit. I would say the method I used previously would have to be better.
    • GTSBoy
      DeAgostini 1/8 scale BNR32 Nissan Skyline GT-R Nismo

      By GTSBoy · Posted

      That's hilariously putrid!
    • GTSBoy
      R33 Fuel Pump & Brakes after alarm swap

      By GTSBoy · Posted

      When I said "wiring diagram", I meant the car's wiring diagram. You need to understand how and when 12V appears on certain wires/terminals, when 0V is allowed to appear on certain wires/terminals (which is the difference between supply side switching, and earth side switching), for the way that the car is supposed to work without the immobiliser. Then you start looking for those voltages in the appropriate places at the appropriate times (ie, relay terminals, ECU terminals, fuel pump terminals, at different ignition switch positions, and at times such as "immediately after switching to ON" and "say, 5-10s after switching to ON". You will find that you are not getting what you need when and where you need it, and because you understand what you need and when, from working through the wiring diagram, you can then likely work out why you're not getting it. And that will lead you to the mess that has been made of the associated wires around the immobiliser. But seriously, there is no way that we will be able to find or lead you to the fault from here. You will have to do it at the car, because it will be something f**ked up, and there are a near infinite number of ways for it to be f**ked up. The wiring diagram will give you wire colours and pin numbers and so you can do continuity testing and voltage/time probing and start to work out what is right and what is wrong. I can only close my eyes and imagine a rat's nest of wiring under the dash. You can actually see and touch it.
    • Kinkstaah
      Mistakes were made, my R34 Story

      By Kinkstaah · Posted

      So I found this: https://www.efihardware.com/temperature-sensor-voltage-calculator I didn't know what the pullup resistor is. So I thought if I used my table of known values I could estimate it by putting a value into the pullup resistor, and this should line up with the voltages I had measured. Eventually I got this table out of it by using 210ohms as the pullup resistor. 180C 0.232V - Predicted 175C 0.254V - Predicted 170C 0.278V - Predicted 165C 0.305V - Predicted 160C 0.336V - Predicted 155C 0.369V - Predicted 150C 0.407V - Predicted 145C 0.448V - Predicted 140C 0.494V - Predicted 135C 0.545V - Predicted 130C 0.603V - Predicted 125C 0.668V - Predicted 120C 0.740V - Predicted 115C 0.817V - Predicted 110C 0.914V - Predicted 105C 1.023V - Predicted 100C 1.15V 90C 1.42V - Predicted 85C 1.59V 80C 1.74V 75C 1.94V 70C 2.10V 65C 2.33V 60C 2.56V 58C 2.68V 57C 2.70V 56C 2.74V 55C 2.78V 54C 2.80V 50C 2.98V 49C 3.06V 47C 3.18V 45C 3.23V 43C 3.36V 40C 3.51V 37C 3.67V 35C 3.75V 30C 4.00V As before, the formula in HPTuners is here: https://www.hptuners.com/documentation/files/VCM-Scanner/Content/vcm_scanner/defining_a_transform.htm?Highlight=defining a transform Specifically: In my case I used 50C and 150C, given the sensor is supposedly for that. Input 1 = 2.98V Output 1 = 50C Input 2 = 0.407V Output 2 = 150C (0.407-2.98) / (150-50) -2.573/100 = -0.02573 2.98/-0.02573 + 47.045 = 50 So the corresponding formula should be: (Input / -0.02573) + 47.045 = Output.   If someone can confirm my math it'd be great. Supposedly you can pick any two pairs of the data to make this formula.
×
×
  • Create New...