civicsi0721

yea i was wondering if a 70mm trottle body would be overkill for a jrsc b16.....i am running s300 and i will retune it after i put it in so will it be worth it will i make aany more power os is it just too big....the supercharger is at 9psi and is not intercooled....

JDMCRX

iTrader: (2)

Its not over kill but porting out the S neck the 70mm is cutting into the ICV. I think the best is a 68mm

HiProfile

A 62mm TB would be overkill, considering the minimal gains. The S-tube is the real killer, then the blower's inlet port, THEN the TB. It also assumes you've ported the s-tube, and that it can support a 70mm TB.

A bigger TB doesn't usually help much in most FI apps (sub 300hp), given that 60mm is already big relative for the inline-4 world. They help NA motors because they're already counting decimals for HP gains. If it was an M90 blower, I might suggest it before other mods, but yours is just a M62 blower.

civicsi0721

k then will there be any power gains from porting the s tube?

civicsi0721

bump

daveb91

More than the TB.

wunfstgsr

70mm would be nessasary for a built motor and ported lht jrsc manifold, these are not uncomon for lht they will port the tb inlet to 68mm or if requested to 70mm. if its not ported you will not benifit much from a bigger tb the factory jrsc s-tube was desighned for the stock size t.b you can ask kieth at moss motors he will explain in more detail, i will be running a ported head and having the lht manifold custom ported to 70mm when sent to lht sometime soon lol.

JohnnieChimpo

BAD INFO. Do you have a JRSC B16? Probably not.

I have a GSR JRSC. I welded up and ported my S-tube and noticed nice gains with my 76mm throttlebody. Measure the blower's inlet and calculate the square inches, it's more than the square inches of a 76mm TB.

Go to the JRSC thread plenty of guys there running 70mm TBs. LHT will tell you the JRSC is sensitive to intake restrictions. Go to Whipple's site they'll tell you how blower motors like no restriction before the blower and the huge gains they got by adding bigger trottlebodies.

Just because something works a certain way on a turbo engine doesn't mean it works the same on a JRSC engine.

nextproject97

I would call LHT and talk to them keith at moss is a decent guy but John at lht really knows his **** when it comes to the jrsc and what helps it the most. I have talked to keith at moss a few times at at times you can tell he is behind a desk and not somebody who has his hands in engine bays everyday. I just sent my stock s tube to LHT for porting and am going to get the bigger tb 68 mm or whatever John suggest . I was running stock s tube and t.b. I'll see what gains I get on the dyno after the two items gonna be a few weeks though .Probably twoard the end of November when its all back together and dyno'd. I am also switching to full 3" exhaust .Up from a 2.25 / 60 mm.

wunfstgsr

I agree! care to share what process you used to port your s-tube? 76mm! thats crazy whats your setup chimpo? what intake are you using? im running sk2 pro1's in a high comp. n.a gsr motor with 5psi on the jrsc, tuned at churches only hit 230hp so im gonna try a lower comp. with my jg b16 head and a few other mods up my sleave like lht, hytec header! and i was going 70mm but **** if i can go 76mm on the t.b why not!

civicsi0721

ea i read that lht post where he said that they like no restriction and are sensetive on the intake side....lht said there is a 6-8hp gain in a 68mm tb and ported s pipe in the jrsc thread...thats why i was wondering if it will make power on my b16

Ultraspeed DC2

FI isn't the same here. With turbo you'd be pushing through it. In this case it's sucking through, like a straw.

Ditto on the bad info.

civicsi0721

k yea thanks that answered my question i think i will just go with a 68mm tb

and they open up the s pipe to 65mm this is straigth from lht website
http://www.lhtperformance.net/Superc.../upgrades.html



and btw that is a badass header that lht made i wish i could own it lol....if i had 800 i wouldnt know which one to get first the headere or the intercooler but they both are grade aaaaaaa parts