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Gtr cam timing for mid range torque

pnblight

By pnblight,
in Engines & Forced Induction

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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
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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
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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
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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.

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