70mm throttle body on stock motor pro&cons?

[Whitettype86]

Well I have a accufab 70mm and precision phelum with Rjc air spacer sitting around. Wonder if I should install it on my stock motor. I remember in the past that this topic was descussed on. So what would happen or is there any benfits?

 

[SHADOWII]

Do like Thomas Edison,

he learned something even in his failures! He knew what wouldn't work and why. :biggrin: seriously, in one of the gm-hi-tech write-ups, a 62/5mm was added to the project car, and it lost a little. I don't recall if they had the advantage of the rjc plate or not. The worst case, is, you get to inform the rest of us that it doesn't work! :biggrin:

 

[VadersV6]

Cant judge everything on that magazine article. A different combo will respond differently. But of course a big TB is a waste of time on a stock motor. The up-pipe measures over 63mm. If the IC is a good free flowing piece, the TB is an obvious restriction. You flow through an IC with 2.5" pipes, then through a 2.5" up-pipe, and then squeeze through a 2 1/4" TB. I dont think you'll be losing alot of power with the stocker, but it would be nice to have a TB thats at least the same size as everything else....62mm. Throttle response would be better as well. If u have a big turbo, big IC, pushing alot of boost...yeah a 70mm TB would probably work pretty well.

 

[Hammer231]

At one point does a larger than stock throttle body become an asset? 12 sec car? 11 sec car?

 

[bison]

At one point does a larger than stock throttle body become an asset? 12 sec car? 11 sec car?

It depends on the cfm flow of the engine. Higher rpm 6000+ and more cubes requires a bigger TB. Its more rpm related than anything.

 

[JC Turbo]

There are guys running in the 9's with just ported stockers. I know the stock TB can only go to 62 mm.

 

[Raist103]

it was the first mod on my stock car "other then a chip" and although i saw no track time till i got the 49 on the worst the car has gone is a 12.9 on street tires and runs 12.2 all day on low boost launches and spinning drag tires. i noticed a good difference just adding 70mm tb and doghouse and a 3" chrome up pipe. i then added a 3" chrome intake pipe with k&N when i did the 49 and saw more power i have not run the car with the new setup on there and tuned yet but my entire point is i DID notice a better difference just adding the 70tb and dh.

 

[Raist103]

oh i did not have a power plate either

 

[Blazer406]

Someone at the nats.... said Red Armstrong was runnning a stocker on his.... and his car ran mid 9's. Most not be too much there... or looks like he would have one.......

He was running a Hemco.....and a stock type TB per my visual inspection..... someone I know told me he was running a stock TB......

 

[bison]

Anyone have any dyno info? I find it hard to believe there is much to be gained over the 62mm on an engine that stays under 5500rpm.