so one of the many areas in which j bodies lack serious aftermarket support is throttle bodies
I surfed endlessly looking for alternatives to the RSM 62mm tbody and the short lived billet JBP throttle body
my search turned up a promising result.
Saturn MotorSports.
everyone knows the saturn ion also has the L61, but throttle body solutions for them won't work for us due to throttle by wire.
Guess what. Not all ions have throttle by wire.
the 03-04 Ion (NON REDLINE) is a cable just like us. I do not have measurements on the throttle body yet, but it is just shy of 2.75" inner diameter on the inlet however close investigation determined that the tbody, even tho the butterfly is larger, tapers in and by the rear side of the tbody is stock in diameter. phooey =\
looking at the ports inside its a wonder how RSM made it 62 mm at all seeing as there is very little room to play with as far as opening up the throat of the engine which probably explains why there's so few tbodies available for us.
anyone have pictures of the REAR of the RSM tbody to see if it truly is 62mm all the way through?
anyway, here's the pictures of the tbody:
stock 59mm throttly body
SMS 69mm (?) throttle body
stock is left, SMS is right
different lighting
comparison of the rears of the throttle bodies.. note the exact similiarity in the port sizing
installed on the skwirl
closer view
first impression: excited
after inspection: somewhat disappointed
the throttle body is a great peice, nice work done to it but it is not a straight through design for obvious reasons. The ports can only be touched so much before you get a 9k RPM idle. my tbody sticks a little because I don't think the plate was properly sized to the tbody. after some sanding of a rough edge with some 200grit it was a little better, but not by much. There's a small stop screw for the bellcrank that isn't where it should be. after I adjust that it shouldn't get sticky anymore
Idle is normal
butt dyno reports the car is a bit more top end happy of course it could be weather, it could be my psychosis. unfortunately my track testing will be skewed since I'll have cams and no balance shafts when I hit it next time... perhaps we'll see
all in all, skwirl's conclusion is 2 nuts out of 5
the throttle body was expensive, and with some work on my part COULD be made to be a straight thru design.. a solution I plan on working on for us all in the future, however as a direct bolt on part I would suggest at least checking it out before hand or having someone who knows what to do check it out.
but other than that, the tbody was a direct bolt on. swap the sensors over and bam ready to rock.
as far as a true blue straight thru design.. the search goes on..
the throttle body can be found
here
I am sorry but my thoguhts were confirmed, good luck on getting us something going....
LE61T PTE6262 Powered 
on the price. nice write up on that TB. Deffinately keep us posted on any other findings for TB's for the eco.
hmm
im disappointed now i hoped this would work out
1989 Turbo Trans Am #82, 2007 Cobalt SS G85
Hmmm, levelzero has a CNC machine... hmm... hey Clay you know what I want and 62mm isnt big enough.
Isn't $173 cheap for a bored throttle body?
looks like a nice pice. walls on the tb look extremely thin. 172 aint bad. core charge is needed. lol i still have 2 stock throttle boddies sitting in my garage.
wonder if a company will actually make an aftermarket tb for the ecotec rather then just a bored stock one? guessing doubtful do to it only being made for 3 years since the cobalt is electronic.
http://www.myspace.com/15102113
Hey PJ,
Are you sure the throttle plates are diff sizes?
I can tell the mouths are different.
But it looks like the plates are the same size?
How did you get a 59mm factory tb?
The plate I have is 58mm.
-M
Remember....syringes go in the RED waste basket.
mastin, i'm pretty sure the eco tbody is 59, but I could be wrong I was quoting memory
I'm not positive on the butterflies either, which warrants disassembly of the SMS tbody and a much closer investigation
with the proper measuring tools
the other thing is the sms butterfly is at a slight angle so its a bit larger in reality than it looks in the pictures
but until I disassemble it (I need torx wrenches) this is all speculation
at the very least I can use the dimensions and the design to start experimenting with fabricating or machining my own tbody
or, maybe someone can step up and FINALLY offer a real deal straight thru CNC machined tbody <cough>clay<cough>
so I guess tyhat sucker is not 69mm at the plate then?
Well,
I do like how paper thin they made the opening of the mouth.
So definately larger there.
But its all about the plate,
And the red color is cool.
i wonder if they give color options.
-M
Remember....syringes go in the RED waste basket.
they dont give color options or else i woulda got blue
also, you'll never see it so it doesn't really matter =P
but yea the butterfly is def NOT 69mm altho it is def larger than stock
the butt dyno still says that the car is happier in the top end, I mean it may have
smoothed out flow and eliminated some turbulence or something to that effect
but the gain isn't enough (if there is any) to feel
I already am working on a completely new idea that will pretty much blow all your minds
I like when PH says he's going to blow us in some way
LE61T PTE6262 Powered
you missed the J phil
i'm drawing up some designs now... all I need to do is find the right throttle bodies
I'm also working on another more mild solution as well...
in the form of a retrofitted focus 65mm billet throttle body.. anodized blue
IAC is a whore.. but relocation isn't out of the question
I'll post my results after some testing
I think the more extreme of my two ideas will definetly drop some jaws
looks good. not that bad of a price.
i would like to see a dyno of how much this product gains over stock.
