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Discussion Starter #1
Hello all,

I'm going to be fitting some Poncams in my GTR soon, I have bought the rocker cover gaskets and the half moons too and I am not sure about something..

- The Poncams are just direct replacement without re-shimming... have many of you had to reshim even with 'drop in' cams?

- Of course I will check before and after clearance, but I do not want to buy shims because I do not know what shim sizes to buy. If after I remove the original camshafts, I will need to order some and wait around with my rocker cover off?? Is that what people do??


Also, I believe I will need to have my car remapped after the camshafts... I have only had it remapped 3 months ago (did not plan on getting camshafts at the time).... is there anything I can do with the Apexi FC ECU with hand commander to get the car running right??

Are there any other things to look out for, or anything else worth changing whilst I have it all off?

Thanks in advance y'all

:bowdown1:
 

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Poncams though drop in you might need to reshim each engine is a little taking into consideration the wear factor but in any case clearances would need to be checked.
 

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make sure you remove and redo the camholder bolts in the correct sequence and to correct torque.
 

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I'll drop my pants on national TV if it doesnt need a shim or two. Mate, if your installing yourself be soooooooooo mindful to your tightening sequence or you will snap your cam in half!!
 

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They're not a direct replacement without shimming. You have to check valve clearances with any cam you fit but you won't need to relieve the head for lobe clearance or worry about base circle differences with Poncams. Its a case of :

Measure all your current shims and write down their locations
Fit cams
Measure clearances
Work out where to reposition your current shims to achieve the correct clearances and then buy new shims for the rest.
Try Nissan for shims before going to the tuners. The one I needed for my build was £6 from Nissan and Abbey charged me £20 for a 2nd hand one. Unfortunately time meant I couldn't wait for Nissan to supply. :rolleyes:

You'll need to get it re-mapped and it would be a good idea to fit adjustable cam wheels so you can time the cams properly for a base setting and then get them to optimise the cam timing on the dyno during mapping to get the best results from them. You should find the current map will be ok to get it to the dyno but don't hammer it.
 

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Discussion Starter #7
Awesome feedback guys, appreciate all of it.

I had a feeling it would be like this..

But I'm thinking... logically... If the Poncams are made as 'drop in' cams.. then they would be designed for the OEM sized shims, so if I buy a whole set of OEM shims, and then stick them in then happy days, right? Or no? Because of general wear of other items?

I wanted to do the cam change within 1 day... but sound like there will be some faffing about trying to understand, order and wait for the correct shims that I need.. :(
 

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You get different sized shims so you need to measure the clearances in order to a certain what shims sizes you need to order...
 

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Awesome feedback guys, appreciate all of it.

I had a feeling it would be like this..

But I'm thinking... logically... If the Poncams are made as 'drop in' cams.. then they would be designed for the OEM sized shims, so if I buy a whole set of OEM shims, and then stick them in then happy days, right? Or no? Because of general wear of other items?

I wanted to do the cam change within 1 day... but sound like there will be some faffing about trying to understand, order and wait for the correct shims that I need.. :(

They're 'drop in' in as much as you dont need any other supporting parts/mods as you may do with other higher lift/duration cams.

You'll STILL need to do the clearances though!!!!!!

:confused::confused:


TT
 

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£20 for a used shim compared to £6 of Nissan brand new? Now I have heard it all :runaway:

That's nothing I needed 12 shims for my intake cam I went to Nissan who couldn't get them I eventually found some for £250 + vat for 12 yes that's 12 tiny discs of metal
That was from a reputable tuner in the north west

Needless to say I bought some cobalt steel and had them made £90 inc vat
 

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I machined out the retainers and used Peugeot diesel shims. £2 each and they go much thicker so can be used with 30 mm base circle Jun cams.
 
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