Throttle Body Size help

[68efisuper]

I have a 92 5.0 motor with a Kenne Bell 1.5l blower. The motor has afr 165 heads a healthy cam,headers, roller rockers, C@l Maf. Trying to upgrade the throtte body, but not sure which size, any help would be appreciated. Thanks

 

[87'GTstang]

The port on the Kenne Bell accepts as large as a 70 mm unit, so go 70.

 

[Deleted member 87397]

+1

 

[Hi-Po]

I have a '92 LX with a KB 1.5 L as well, however my engine is all stock except for the blower and a CAI. I asked Kenne Bell what TB they would recommend for my current setup and they replied Accufab 75 mm. According to KB the blower intake will accept a 75 mm TB without any porting. In my opinion this sounds too large, but then again I guess they would not recommend something that would affect performance/drivability in a negative way. Eventually I will upgrade my engine with further mods, but I have decided (more or less) that time being I am going to go with an Edelbrock TB 70 mm...

 

[WLDHRSE]

I would go 75 mm Accufab. 70 mm seems a little small for heads and blower.

Cliff

 

[jaybquick]

70mm is too small. I have a 75mm on my 347 and it makes plenty of torque and it is a low CR NA motor.

 

[87'GTstang]

Forced induction is a different animal compared with N/A. With a smaller throttle body you are not asking and big-inch stroker to "suck" through a straw. Boost will force itself where it wants to go. If it would be most beneficial to put a 90mm TB on a blown 5.0, would I do it? No, simply because that would be for maximum performance at high rpm's, low speed drivability may not have very good manners. If you mostly do not go past 5000 rpm and mostly do a lot of cruising, the infamous 65mm that so many turbo gurus use may even be more beneficial. I would definitely cap it at 75 though and go no higher.

 

[jaybquick]

it is a kenne bell not a centrifugal or turbo, they make plenty of low end torque, 75 mm might cost him 5 ft lbs, maybe. Might as mell not cap it on the top end. My roots blower on my carbed car hated small carbs. Some concept since it is not blowing through the throttle body but sucking with the Kenne.

 

[5spd GT]

jaybquick - So a big 5mm difference is what makes a throttle body "too small" and then 5mm later it is "just right"...lol.

87GTStang is right on...

70mm TB would be just fine...and your gas wouldn't be so touchy for stop and go traffic.

Stick with the 70mm TB. If you want every bit of high-end hp, get the 75mm TB.

The Kenne-Bell will help make up for whatever "torque" you may or may not lose...

 

[jaybquick]

jaybquick - So a big 5mm difference is what makes a throttle body "too small" and then 5mm later it is "just right"...lol.

87GTStang is right on...

70mm TB would be just fine...and your gas wouldn't be so touchy for stop and go traffic.

Stick with the 70mm TB. If you want every bit of high-end hp, get the 75mm TB.

The Kenne-Bell will help make up for whatever "torque" you may or may not lose...

My whole point is that it can fit 75 mm for a reason. Just run it. Like you said and I said before the torque will come from the Kenne-Bell, so why not help out the top end some.