it's gonna be a 81.5mm gsr bottom end with 11:8-12:0 comp wiseco pistons..

the head will be fully ported, valve job.. and over sized valves, edelbrock victor x intake mani with stock cams for now..

question is, which will be better? a 65mm or a 70mm throttle body?

i plan on doing a 50-75 shot when i get a little bit more cash

 

I'd watch out running oversized valves if you plan on running big cams some day. Also, think twice about the victor x. You need to be making a lot of power up top for that manifold to work for you. Performer X would be better if you want to go edelbrock.

 

os valves in street car bseries will not benefit you at all. It may actually hurt performance. and yes with a big cam it may cause even more problems.

As for the TB size id like to know myself. I was always unsure if that would help or hurt intake air velocity ? Also will it be better if the plenum was port matched to the TB and the runners matched to the head ?

 

velocity not volume

 

stock cams

 

yeah ew stock cams for now.. looking for a good deal on skunk2's when i get more money..

but anyway what's wrong with over sized valves?... i guess the way you're trying to tell me it would only benifit is if i was turbo charged or something maybe?..

my engine builder recommended to get oversized valves, and it doesn't really seem it would really hurt me at all.. but i'm open to any imput you guys have!

 

the face of the valve being larger just causes more restriction of the intake and exhaust gases. It has more to flow around.

 

you would need a heavy port job for the o/s valves. maybe one of the head experts will chime in to explain better. i like the itr throttle body and manifold. simple yet very effective

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 4g hatch &raquo;</TD></TR><TR><TD CLASS="quote">you would need a heavy port job for the o/s valves. maybe one of the head experts will chime in to explain better. i like the itr throttle body and manifold. simple yet very effective</TD></TR></TABLE>

oowie, well i already bought a edelbrock victor x, so scratch the ITR manifold idea.. but how many mm is a itr throttle body anyway?

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by lude98SH &raquo;</TD></TR><TR><TD CLASS="quote">the face of the valve being larger just causes more restriction of the intake and exhaust gases. It has more to flow around. </TD></TR></TABLE>
ooHhh, that explains it alittle better

 

i would trade for a itr or a blox,skunk,or even a aebs that thing is going to kill you in the low and mid range. not trying to tell you what to do just trying to help.

 

i always thought the type r throttle body was 62mm but experts feel free to jump in!

 

i thought it was 64. but they still will work. alot of guys run that and run near 200hp

 

Oh yeah. Before I bought the victor x I was debating upon that manifold and the performer x (it having hell of alot more mid range) but I decided with the victor x, since that's where I'd like to make all of my power when I get cams..

But anywho.. I guess any throttle body could be better then stock.. Ill shoot for a 68 mm or so

 

I would go with a 68 mm throttle body.

 

i dont know if this will help out any, but i ran a victor x with a professional products throttle body (68mm tapered down to 65mm) on a 81.5mm 12.5:1 compression ls-v with bc spec 4 cams. i didnt make any power till 7k.. imo, it was horrible. now i have my ITR manifold back on the the victor x is just sitting in a box. tuned the car twice also.