i plan on building my bottom end up next summer to finish my fully built GSR...i was thinking of sleeving the block with darton sleeves and boring to 84mm, would that raise the torque aswell as the hp?? also, what would be a good piston/rod combo to use to raise the compression? ive got skunk2 stage2 cams and im running on stock GSR compression now so i need to raise it to 11:1 or more probably to get the full power out of the cams. could i use jdm ITR or CTR pistons with my stock gsr rods? if so, what kinda compression would i get? my main question is, would it be worth it to bore to 84mm for the torque and hp? or could i do just a much with 81mm slugs and rods with a good header (jdm dc 4-1??) and proper tuning? i plan to use hondata s100 next summer too. so i can get everything finely tuned.

 

Depends on your budget or ultimate goal...You can use CTR pistons with stock rods and will raise your comp over 11 and that's pretty decent. Adding your Skunk2 cams, header and Hondata to that, with proper tuning you may be looking at about 190whp. To answer your other question, boring to 84mm, sleeving the block would cost you a lot more $$, but more power too. Just do the math and take a pick. I'd sleeve if I were you. Everyone else is using CTR pistons and Skunk2 valvetrain...

 

All depends on your budget. Stock bore CTR's will give you 12:1 and w/ Stage 2's you should be making pretty good power. Possible to break 200whp on proper tuning.

Sleeving and going to 84mm willl require aftermarket pistons. Your stock rods would be fine so if you were planing on spending 400-600 on aftermarket rods put that towards sleeving. There will also be more down time with this as not a lot of machine shops around to sleeve without sending out. I think it's worth it, but that's just me. It is true there's no replacement for displacement no matter what anyone says.

 

im almost positive i wanna bore to 84mm for the extra power, ill spend the $, i think it would be worth it, but do they not make oversized CTR pistons that would fit my stock rods? and if i use my stock rods, would they be safe to run up to 10k rpm?...i think i need atleast 11.5:1 or 12:1 compression would be even better for my cams. also, i was talking to david from SMSP about this and he was saying something like, if i go to 84mm/2.0L, then the DC jdm4-1 header wouldnt be sufficient, id need a different header. anyone know for sure?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 96redgsr &raquo;</TD></TR><TR><TD CLASS="quote">...if i go to 84mm/2.0L, then the DC jdm4-1 header wouldnt be sufficient, id need a different header. anyone know for sure?</TD></TR></TABLE>

You'd definetly need a higher end header for that power, me personally Id get a race hearder from either one of these guys (SMSP, Hytech, headertech). The poor 2.0 would choke....

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 96redgsr &raquo;</TD></TR><TR><TD CLASS="quote">do they not make oversized CTR pistons that would fit my stock rods? and if i use my stock rods, would they be safe to run up to 10k rpm?...i think i need atleast 11.5:1 or 12:1 compression would be even better for my cams. </TD></TR></TABLE>

Biggest CTR pistons you can get are only .25 over (81.25mm). And as for running 10K on stock rods, I'm sure you can but not guaranteed. Be on the safe side since you're already spending for your motor. Have the peace of mind that you can rev pass 10K and still have power. (Sleeve, oversized forged pistons, aftermarket rods, smsp header)=

 

As I stated earlier if you go 84mm bore you HAVE to get aftermarket pistons. CTR's don't come that big. Yes you will defenetley want a better header for your motor to reach it's max potential. Why would you want to rev to 10K? You will not make power that high.

 

i was just using 10k as an extreme example, but with higher compression teh skunk2 stage 2 cams that i have would pull all the way through 9k+ before dropping off, but right now with stock compression they peak at 7800, so i deffinatly need to up the compression. anyone know what kinda torque and hp #s id gain by going to 84mm? thanks.