Jim_1979 Posted April 14, 2008 Share Posted April 14, 2008 Any benefit to doing this? Also, would the car need properly mapped to run these? Quote Link to comment Share on other sites More sharing options...
Jim_1979 Posted April 14, 2008 Author Share Posted April 14, 2008 What's the difference between the UK and Jap cams? Quote Link to comment Share on other sites More sharing options...
Nic Posted April 14, 2008 Share Posted April 14, 2008 The exhaust cam is the same on both models, the UK spec has longer duration and higher lift intake cam J-spec Intake Duration 224° Intake Camshaft lift 7.88mm Intake valve diameter 33.5mm Intake Valve timing - Opening 3° BTDC Intake Valve timing - Closing 50° ABDC Exhaust Duration 233° Exhaust Camshaft lift 8.4mm Exhaust valve diameter 29mm Exhaust Valve timing - Opening 52° BBDC Exhaust Valve timing - Closing 4° ATDC UK Spec Intake Duration 233° Intake Camshaft lift 8.25mm Intake valve diameter 33.5mm Intake Valve timing - Opening 3° BTDC Intake Valve timing - Closing 50° ABDC Exhaust Duration 233° Exhaust Camshaft lift 8.4mm Exhaust valve diameter 29mm Exhaust Valve timing - Opening 52° BBDC Exhaust Valve timing - Closing 4° ATDC Quote Link to comment Share on other sites More sharing options...
mrgee2jz Posted October 1, 2010 Share Posted October 1, 2010 Any benefit to doing this? Also, would the car need properly mapped to run these? Exactly my question???? I have built an engine using these cams, can they be safely run with the std jap spec ECU or do you swap in 550cc UK injectors and ECU? and if you swap in the ecu does it run without an AFM and on the JAP loom???? Quote Link to comment Share on other sites More sharing options...
paul mac Posted October 3, 2010 Share Posted October 3, 2010 i would say that the very modest power increase of about 10 hp you get from this cam the stock injectors would be able to cope, you really would have to get a dyno run to make sure the fueling is ok, an old signal fudger like an SAFC would be ideal for this basic mod Quote Link to comment Share on other sites More sharing options...
mrgee2jz Posted October 4, 2010 Share Posted October 4, 2010 its all together and running now, runs fine, BUT inbetween gear changes (auto) it seems like it cuts too much timing and give me extra lag, also the same off the line, too much lag?? as if its retarding timing?? Quote Link to comment Share on other sites More sharing options...
mrgee2jz Posted October 10, 2010 Share Posted October 10, 2010 Anyone ? Quote Link to comment Share on other sites More sharing options...
David P Posted December 6, 2010 Share Posted December 6, 2010 (edited) These are the specs given for the J spec cams given on http://mkiv.supras.org.nz/specs.htm Intake valve dia. 33.5 mm Intake valve lift 7.8 mm Exhaust valve dia. 29.0 mm Exhaust valve lift 8.4 mm Intake opening 3 deg BTDC - 41 deg ABDC Exhaust opening 52 deg BBDC - 4 deg ATDC Very different to those posted by Nic. Which figures are correct? Has anyone ever considered fitting an N/A inlet cam to their T.T. Intake valve dia. 33.5 mm Intake valve lift 8.3 mm Exhaust valve dia. 29.0 mm Exhaust valve lift 8.4 mm Intake opening 3 deg BTDC - 52 deg ABDC Exhaust opening 52 deg BBDC - 4 deg ATDC Edited December 6, 2010 by David P (see edit history) Quote Link to comment Share on other sites More sharing options...
Nic Posted December 6, 2010 Share Posted December 6, 2010 The figures I quoted above were from here http://www.turbosupras.com/pages/en/pages/specifications/JZA80/jza80.htm Quote Link to comment Share on other sites More sharing options...
David P Posted December 6, 2010 Share Posted December 6, 2010 (edited) Looks like a Supracunundrum Edited December 6, 2010 by David P (see edit history) Quote Link to comment Share on other sites More sharing options...
David P Posted December 6, 2010 Share Posted December 6, 2010 The spec for the N/A inlet cam is different too. Is there a Supra Guru who can advise which of these sites has got it right. This difference makes quite a difference to my dynamic compression calcs. Quote Link to comment Share on other sites More sharing options...
Digsy Posted December 7, 2010 Share Posted December 7, 2010 (edited) No disrespect, Nic, but those numbers don't make sense. The durations and valve opening / closing timings don't match. Assuming the valve opening / closing events are correct I've calculated the proper durations. See my notes in your quote. This would mean that the durations for UK and J-spec were the same, but with different lifts. I suspect that the info on the website is wrong. The exhaust cam is the same on both models, the UK spec has longer duration and higher lift intake cam J-spec Intake Duration 224° - Should be 233° Intake Camshaft lift 7.88mm Intake valve diameter 33.5mm Intake Valve timing - Opening 3° BTDC Intake Valve timing - Closing 50° ABDC Exhaust Duration 233° - Should be 236° Exhaust Camshaft lift 8.4mm Exhaust valve diameter 29mm Exhaust Valve timing - Opening 52° BBDC Exhaust Valve timing - Closing 4° ATDC UK Spec Intake Duration 233° - Correct Intake Camshaft lift 8.25mm Intake valve diameter 33.5mm Intake Valve timing - Opening 3° BTDC Intake Valve timing - Closing 50° ABDC Exhaust Duration 233° - Should be 236° Exhaust Camshaft lift 8.4mm Exhaust valve diameter 29mm Exhaust Valve timing - Opening 52° BBDC Exhaust Valve timing - Closing 4° ATDC Edited December 7, 2010 by Digsy (see edit history) Quote Link to comment Share on other sites More sharing options...
Nic Posted December 7, 2010 Share Posted December 7, 2010 (edited) No disrespect, Nic, but those numbers don't make sense. The durations and valve opening / closing timings don't match. Assuming the valve opening / closing events are correct I've calculated the proper durations. See my notes in your quote. This would mean that the durations for UK and J-spec were the same, but with different lifts. I suspect that the info on the website is wrong. You're the expert Darren I just copied and pasted the info from http://www.turbosupras.com/pages/en/pages/specifications/JZA80/jza80.htm Do the figures from http://mkiv.supras.org.nz/specs.htm that David posted earlier look correct? Edited December 7, 2010 by Nic (see edit history) Quote Link to comment Share on other sites More sharing options...
Digsy Posted December 7, 2010 Share Posted December 7, 2010 Its difficult to tell as they only quote the valve open / close events. The durations from the NZ site would be: TT intake: 224deg x 7.8 lift TT exhaust: 236deg x 8.4 lift NA intake: 235deg x 8.3 lift NA exhaust: 236deg x 8.4 lift Looks like the exhaust cam is common and the intake valve closing figure might be wrong in the data you posted, as the duration and intake valve opening figures match. Of course the NZ site doesn't say if their data is J-spec, Uk or Federal. Quote Link to comment Share on other sites More sharing options...
mrgee2jz Posted December 7, 2010 Share Posted December 7, 2010 i have uk cams on my j spec but not pushing it too hard. im going to replace them with j specs as im only staying bpu and not mapping. the UK's would be great for someone thats going to remap with larger injectors. say 550's or larger or maybe even doing a hybrid turbo conversion. Quote Link to comment Share on other sites More sharing options...
David P Posted December 7, 2010 Share Posted December 7, 2010 i have uk cams on my j spec but not pushing it too hard. im going to replace them with j specs as im only staying bpu and not mapping. the UK's would be great for someone thats going to remap with larger injectors. say 550's or larger or maybe even doing a hybrid turbo conversion. No need to change the exhaust cam as they are the same. But looks like an N/A inlet cam could give gains, maybe Digsy could comment. Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted December 7, 2010 Share Posted December 7, 2010 Neither site gives enough information to meaningfully compare the cams. Duration at what lift is the missing link. Without that it's all speculative. i have posted this before, but this is what a proper cam spec sheet looks like. If anyone wants to pay I can measure the cams on a Cam Doctor type machine. -------------------------------------------------------------------------------- CAM PRO PLUS Cam Card Report 11:42:59 08/10/2010 -------------------------------------------------------------------------------- Spec. Value ---------------- ----------------------------------------- File x:\Chris Wilson Direct acting mechanical profiles\D300-D399\D361.CPP Lobes I1 Lobe Separation ----- Cam Deg. Checking Height 0.010 Inch Valve Overlap ----- Crank Deg. Intake Exhaust ------------------- ------------------- Centerline 106.0 ATDC Open 44.8 BTDC Close 76.9 ABDC Duration 301.8 Crank Deg. Area 37.12 Inch Deg. Lash 0.0250 Inch Rocker Ratio 1.00 Peak Cam Lift 0.43405 Inch Peak Valve Lift 0.40905 Inch Lift @ TDC 0.1363 Inch ------------------------------------------------------------- Spec. Value ---------------- ----------------------------------------- Checking Height 0.039 Inch Valve Overlap ----- Crank Deg. Intake Exhaust ------------------- ------------------- Centerline 106.0 ATDC Open 21.3 BTDC Close 52.2 ABDC Duration 253.5 Crank Deg. Area 36.69 Inch Deg. Lash 0.0250 Inch Rocker Ratio 1.00 Peak Cam Lift 0.43405 Inch Peak Valve Lift 0.40905 Inch Lift @ TDC 0.1363 Inch Quote Link to comment Share on other sites More sharing options...
David P Posted December 7, 2010 Share Posted December 7, 2010 (edited) For all the years of chitchat re. T.T. tuning, I am amazed this information is unknown. Cams are costly items, and it looks a possibility that fitting an N/A inlet cam to a T.T. could be a very cheap way to add BHP to BPU. BPEU maybe? Edited December 7, 2010 by David P (see edit history) Quote Link to comment Share on other sites More sharing options...
Digsy Posted December 7, 2010 Share Posted December 7, 2010 Neither site gives enough information to meaningfully compare the cams. Well, to be fair a lot of the information is there but you just have to work it out from the figures given, but I agree the key thing that is missing is the time x area figure. -------------------------------------------------------------------------------- CAM PRO PLUS Cam Card Report 11:42:59 08/10/2010 -------------------------------------------------------------------------------- Spec. Value ---------------- ----------------------------------------- File x:\Chris Wilson Direct acting mechanical profiles\D300-D399\D361.CPP Lobes I1 Lobe Separation ----- Cam Deg. Checking Height 0.010 Inch Valve Overlap ----- Crank Deg. Intake Exhaust ------------------- ------------------- Centerline 106.0 ATDC This equals (DURATION/2) - OPEN (provided the cam profile is symmetric. Open 44.8 BTDC Close 76.9 ABDC Duration 301.8 Crank Deg. Is OPEN + CLOSE + 180 for all of the examples so far quoted. Area 37.12 Inch Deg. Lash 0.0250 Inch Cold clearance (i.e. tappet clearance) Rocker Ratio 1.00 This is always 1.00 for a direct acting valvetrain Peak Cam Lift 0.43405 Inch Maximum lift on the cam Peak Valve Lift 0.40905 Inch Equals max cam lift minus the cold clearance (lash) Lift @ TDC 0.1363 Inch ------------------------------------------------------------- Quote Link to comment Share on other sites More sharing options...
David P Posted April 2, 2011 Share Posted April 2, 2011 Found a couple of threads about this on Supraforum, it looks like the N/A inlet cam gives the T.T. another 10bhp?, with adjustable cam gears @ +1o inlet -3o exhaust giving 20bhp? more. Very cheap add ons for BPU. Quote Link to comment Share on other sites More sharing options...
David P Posted April 5, 2011 Share Posted April 5, 2011 I am surprised there has been no further input re. this suggestion, this looks to give a nice little power gain @ BPU, 'raising the bar' with simple work at little cost. Quote Link to comment Share on other sites More sharing options...
Smoke_U Posted April 6, 2011 Share Posted April 6, 2011 Found a couple of threads about this on Supraforum, it looks like the N/A inlet cam gives the T.T. another 10bhp?, with adjustable cam gears @ +1o inlet -3o exhaust giving 20bhp? more. Very cheap add ons for BPU. Car needs to be fine tuned and Dynoed right?! Quote Link to comment Share on other sites More sharing options...
dude Posted April 6, 2011 Share Posted April 6, 2011 If your going to all that trouble and expense of labour just fit proper cams and have done with it, I will be able to supply relatively cheap cams in chilled iron pretty soon. Quote Link to comment Share on other sites More sharing options...
David P Posted April 6, 2011 Share Posted April 6, 2011 An N/A inlet cam can be had for the asking then half a days tinkering, and the job is jobbed. An aftermarket standalone or piggy-back ECU and a dyno tune would be best, yet I would think the stock ECU would be O.K. This would need to be trialed, but there is some information about this to be found on Supraforum. I used to tune Toyota deisel engines and to use an N/A inlet cam on a turbocharged engine gave a noticable gain. Quote Link to comment Share on other sites More sharing options...
dude Posted April 6, 2011 Share Posted April 6, 2011 10 hp in a 350 odd hp car, you will never tell the difference, you can gain or lose that due to hot/cold or dry/humid, its only an afternoon if you do not need to shim it, then its a proper job. Quote Link to comment Share on other sites More sharing options...
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