Making 70MM TB's from the stock ones.

[99 R/T 10]

Making 70MM TB\'s from the stock ones.

My question is in trying to figure out how to get get the stock TB's to 70 MM. The local machine shop will bore and hone the ones I have(extra Gen II's) for $100, but I have to disassemble them first(this is going to be fun) and where can I get a larger size flapper(butterfly valve)?

 

[FE 065]

Re: Making 70MM TB\'s from the stock ones.

You know of course most people arent happy with their 70mm TBs, those who are have more mods than you. I think max headwork is the key to being happy with 70mms. Maybe a stronger cam too. I knew a guy spent $2000 on his '95 adding Edelbrock headers and 70mm TBs.. he didn't gain a thing ET wise at the strip. High 12.30s before AND after (following summer) spending all that $$. He said it 'felt faster' on the street, but... I had my '94RT/10's TBs disassembled (throttle shaft/butterfly) once, not a big deal as I recall .

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[Fred(DrivingSchool)Kinder]

Re: Making 70MM TB\'s from the stock ones.

The larger TB's will produce less power on stock motors and no gain on engines with head work and mild cam mods.

Negative result performance results, so Why?

 

[99 R/T 10]

Re: Making 70MM TB\'s from the stock ones.

I know guys, the TB's are in prep for the Roe S/C I have for the next car. I am trying to get everything done ahead of time. Cac't seem to figure out where I am going to get the bigger butterflys?

 

[FE 065]

Re: Making 70MM TB\'s from the stock ones.

Might be better to just buy some 70mm TBs then. Why go through the DIY make your own butterflies route on something that's fairly critical? Hmmm, I'll bet there's someone here that would sell you theirs just to recoup most of their no hp gain investment. Do another post titled "Want to buy used 70mm TBs !" If no one bites, there's enough vendors selling 70s, one of them might sell butterflies .. Be prepared to yank out those 3.73s after you add the S/C.

 

[99 R/T 10]

Re: Making 70MM TB\'s from the stock ones.

Might be better to just buy some 70mm TBs then. Why go through the DIY make your own butterflies route on something that's fairly critical? Hmmm, I'll bet there's someone here that would sell you theirs just to recoup most of their no hp gain investment. Do another post titled "Want to buy used 70mm TBs !" If no one bites, there's enough vendors selling 70s, one of them might sell butterflies .. Be prepared to yank out those 3.73s after you add the S/C.

Someone must have saw you post and beat me to it. So far he has no real bites, but these will not be going on my 96 RT/10, but when I get a Gen II witht he Roe S/C. Gen I has go to go in place of the Gen II, I need to be S/Ced!

 

[Gavin]

Re: Making 70MM TB\'s from the stock ones.

Its my understanding, and I admit limited knowledge on the subject, that stock throttle bodies can be machined (the lip is machined off) to open them up to about 67mm - which is the bore measurement where the stock butterfly resides.

To get to 70mm you need to buy 70mm TB's and the previous folks have nailed it - no gain.

Before deciding the 70mm units will increase the gain under supercharging - confirm that with Sean Roe - this guy has forgotten more about making Viper motors produce power than most know ........ I'm exaggerating but you get the idea - he is the guy to talk to and he makes himself very available.

My recommendation, is don't make mods to any Tuners program without consulting with that tuner - they go through extensive testing of their products and know what works and what doesn't - I learned that lesson with aftermarket brakes - all I did was change to a different brand pad - $2,000 later I had my brake system back to where it was before I changed the brand of pad and I was back to the pad the tuner orginally supplied with his brake package - bottom line I bought a pad that was too thick and i cooked my calipers - bigtime.
Talked to the tuner - he was aware of the issue with the particular pad i attempted to use - had I taken the time to make a call he would have warned me of the problem.

mi10cents

 

[McGuireV10]

Re: Making 70MM TB\'s from the stock ones.

As Gavin says, definitely check with Sean. I just posted to you in the Alley, if I remember correctly back when Sean was in the earlier phases of his SC project I think he mentioned to me that he tested larger TBs and they didn't make any difference.

 

[99 R/T 10]

Re: Making 70MM TB\'s from the stock ones.

As Gavin says, definitely check with Sean. I just posted to you in the Alley, if I remember correctly back when Sean was in the earlier phases of his SC project I think he mentioned to me that he tested larger TBs and they didn't make any difference.

Hey McGuireV10,
I did talk to sean(right after I read your post). He said that in N/A or centrifical S/C cars, the opened up TB's do hurt performance(low end torque). Although in his unit, because in makes power right off the throttle, the 70mm would add aprox. 150 RWTQ! He said they are a good add to the combination for power. He does not open up the stocks, but instead, uses an aftermarket supplier with the kits.

Mike

 

[matt lankford]

Re: Making 70MM TB\'s from the stock ones.

www.BILLETFLOW.COM

he can make you a set of butterflys