Head Bolts size/ Head studs and decompression plate/headgasket

[Alfredo]

Im thinking about building a turbo cg13 engine to drop in to a micra, but I couldn't find any head stud kits nor the size of the head bolts to enquire about custom head studs because I want to run mad boost. The most boost I have seen someone run is 17psi, I want to run 20-22psi, I know that I will have to lower the compression I know of the custom 2mm copper head gaskets that lower the compression to 9.1:1 from the standard 9.5:1 but i was thinking about lowering the compressions to 8.5:1, but i don't know how thick the decompression plate would be, or would running custom low compression pistons be better on budget?

 

[Low Rider]

Head studs are M10. ARP Part No. 151-4203 studs fit and are readily available.

Out of interest, why 20-22psi? What power/torque are you trying to achieve?

 

[Alfredo]

I would like 220hp or in that region, I will only need 20psi boost to achieve that hp figure, 17psi made 200hp. Thanks for the part number as well, will add that to the parts list.

 

[frank]

2mm is about the maximum that the lower chain will allow alfredo, did they use stock pistons on that 200hp build ?

 

[Alfredo]

They used custom SPS Forged 2mm taller crown on custom PAR forged billet rods that were 2mm shorter, that gave 8.2:1 compression, which is really the compression ratio that i should really go for with 20psi

 

[Alfredo]

I can always run water meth injection as well and run more or less boost

 

[frank]

Super S Dave ran water/meths last year alfredo, he might be able to advise eh

 

[Alfredo]

yh, i was thinking of using a universal kit from devilsown with their 4 port direct injection upgrade, i still need to find out the information for nozzle sizing (whether the nozzle size has to be quartered because its split from 1 nozzle to 4, so it injects the right amount, im not sure yet though...)