im trying to see if a 70mm throttle body is too big for my setup. the setup is b18a1 bored to 81.5mm w/ golden eagle blockguard,wiseco 11.4:1 pistons, eagle h-beam rods,exospeed stage 3 race head, ported and polished, stanless steel swirl polished valves, supertech valvesprings and retainers, brian crower stage 2 cams, blox intake manifold, jdm 4-1 header w/ 2.5"collector, golden eagle fuel rail, 310cc injectors, short ram intake, blox velocity stack,and zex 100 shot dry nitrous. the car is being converted to obd1, and will be getting dyno tuned when i finsh putting motor together. will the blox 70mm hrottle body be ok?

 

anyone?

 

take that 70mm throttle body and a stock or slightly larger one to the dyno when you get your car tuned and see what size it likes more.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 00Red_SiR &raquo;</TD></TR><TR><TD CLASS="quote">take that 70mm throttle body and a stock or slightly larger one to the dyno when you get your car tuned and see what size it likes more.</TD></TR></TABLE>

Optimally this would be the best way. However making part changes on the dyno at $150 an hour can add up fast if you don't have a cool tuner or a friend with a dyno. Granted the TB is pretty easy, but I can see it taking a half an hour to change it out and tune, then another half to change it back. there's $150.

To the OP - You will see gains on the top end but you may very well have a loss in torque on the low end. I'd try and go with a 62-66mm. 00Red_Sir is right though, the best way is to find out what YOUR motor likes. No one said this **** was going to be cheap.

 

yeah i know and it hasnt been cheap at all, but i just am trying to figure out whether to sell it and go smaller or what.

 

if the head is ported and you have a nice intake manifold a 65-70mm should be sufficient enough

 

**** i made 211whp with a stock LS tb.
setup was:
DNR ported B16 head
JG edlebrock manifold
Skunk stage 2 cams
GSR block
ctr piston

 

yea i just dont want to go too big.

 

yeah, i wouldnt want to go to big either. the last thing you want is the throtle body being larger than the diameter of the intake manifold. the last tuner i talked to is that its horrible to have a "step-down" between the tb and the intake manifold.

i honestly wouldnt go any bigger than a 65. after that, with your set-up, you arent really looking at a whole lot of hp or torque gains.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by anothersickhatch &raquo;</TD></TR><TR><TD CLASS="quote">the last tuner i talked to is that its horrible to have a "step-down" between the tb and the intake manifold.</TD></TR></TABLE>

Really?, as in a horrible because it would cause a bottleneck? I was under the impression that it does not hold a significant effect on power when you step down between TB ---&gt; IM.

The "bottlenecking" and the principles behind it are better applied to the exhaust side IMO.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Dark@Powers &raquo;</TD></TR><TR><TD CLASS="quote">

Really?, as in a horrible because it would cause a bottleneck? I was under the impression that it does not hold a significant effect on power when you step down between TB ---&gt; IM.

The "bottlenecking" and the principles behind it are better applied to the exhaust side IMO.</TD></TR></TABLE>

wise.