I just measured my stock L61 intake manifold's throttle body opening and got 2.214" or 56mm(its tapered and i put my dial caliper in as far as it could go). That doesnt seem right.
BTW the at the top of the tape it might be 57mm(2.230ish) at the most.
Thoughts?
It is 2:30am and possible that i screwed something up.
Tinkles
2003 Cavalier 1SV
Bagged and Blown
nope that sounds right. the factory L61 TB is 56mm
LE61T PTE6262 Powered 
So i guess the next question is for those of us running bored TB's, are we supposed to bore out that opening?
Only if it overhangs the throttle body bore...
Bill Hahn Jr.
Hahn RaceCraft
World's Quickest and Fastest Street J-Bodies
Turbocharging GM FWD's since 1988
www.turbosystem.com
Thanks again for doing that for me Tinkles.. This might be one of the reasons why the 2.4HO manifold makes more power over the stock 2.2 manifold. I bet the bore on that manifold is bigger.
Yep, sure is bigger...the electronic throttles (2.4 type) are huge compared to cable style.
And I shake my head when I think of how many stock 2.4 mannies I've tossed in the trash, lol.
I have some left...what are they going for?
Bill Hahn Jr.
Hahn RaceCraft
World's Quickest and Fastest Street J-Bodies
Turbocharging GM FWD's since 1988
www.turbosystem.com
10 bucks....
I'll take one off your hands.
Seriously though, i think somebody said like $100 or $129 from the dealer. Crateenginedepot has the hole kit for $255 that includes the manifold, adapter plate, adapter plate gasket, intake seals, PCV seal, and brake booster hose.
Make me an offer! PM is fine
Bill Hahn Jr.
Hahn RaceCraft
World's Quickest and Fastest Street J-Bodies
Turbocharging GM FWD's since 1988
www.turbosystem.com
Hmmm - going to have to check if the LE5 mani opening is at least 62mm.
I'll be quite pissed at myself if i left a restriction in the system this easily removed...
Now im curious to see some before/after dynos with a bored TB on a stock manifold.
Tinkles
2003 Cavalier 1SV
Bagged and Blown
Oldskool: The LE5 intake mani is larger than 62mm. I measured it but can't remember what it was when I installed mine so that when my 63mm was ready I could just drop it on, and there's enough room without a problem.
So wouldn't the LE5 make most power if you had a TB that matched the bore size of the intake manifold?
2002 Cavalier "LS Sport"
I measured my LE5 and I think the bore was around ~65-68mm
Antler wrote:So wouldn't the LE5 make most power if you had a TB that matched the bore size of the intake manifold?
Only if a throttle body bore that big is actually required to support a given HP goal...at normally aspirated power levels, there's always a "sweet spot" where going any bigger doesn't add any more power. The downside of being oversized is that it can negatively affect low and midrange velocity, and make the throttle response hypersensitive.
Bill Hahn Jr.
Hahn RaceCraft
World's Quickest and Fastest Street J-Bodies
Turbocharging GM FWD's since 1988
www.turbosystem.com
Thanks Bill Hahn Jr. for the LE5 manifold.. How many more do you have?
You're welcome, thank you too.
Probably a couple...I'll have to take a look about.
Bill Hahn Jr.
Hahn RaceCraft
World's Quickest and Fastest Street J-Bodies
Turbocharging GM FWD's since 1988
www.turbosystem.com
Got the manifold today Bill Thanks again! It looks good, packing was nice and no broken pieces.
