I’ve always read aftermarket throttle bodies suck but I didn’t believe it until I bought one. I have a 76/78mm throttle body from RPM services and I need help.

Problem 1.) When opening the throttle from closed to slightly open I can feel it catch like the throttle plate is slightly too big for the bore. I thought this would wear down after a few hundred miles but it hasn’t. One day I lubed the edges of the throttle plate which made it open silky smooth but of course that didn’t last long.

Problem 2.) It sticks! I have adjusted my throttle cable so it has slack in it. I have adjusted the bolt that limits the pulley movement. I can fully close the throttle by forcing the pulley with my hand. But as soon as I blip the throttle it will never fully close again which means I’m idling at 2k all the time.

These drivability issues are driving me insane. I am considering downgrading to a bored ITR throttle body and just taking the HP hit for better drivability. Any suggestions? Should I switch brands? Go back to OEM?

 

Having the same issues with my 72mm, i too am also going to use stock for better driveability

 

I have had good results with professional products and edelbrock 65mm-ish throttle bodies. Anything that basically keeps the stock casting will make it nicer to drive the car.

 

Once you bore a stock TB you end up with a new plate anyway so that doesn't make much sense that the stock casting will somehow help.

I'd mod the throttle plate... smooth the contact edges to a slight taper to match the angle it meets the casting...

How much HP do you think you'd lose by going back to stock? I can't imagine it's much.

 

i had mine for years now with no problem knock on wood .....i probally shouldnt of said that ...

 

The stock casting helps with idle just in general, retains the stock IACV plumbing, etc.

I have tuned enough cars where the IACV no longer works with aftermarket throttle bodies, and it can make things a pita when using it with a stock ecu based system.

 

Havent had a single problem out of my cheap-O cast 70mm Blox piece.

 

my throttle cable broke on my rpm tb! anyone else have this problem?

 

my rpm tb broke in half, anyone have this problem?

 

The newer blox throttle bodies are MUCH better than the older units.

 

still running my 70mm STR without issue...try to see where the plate is catching and polish it out or something

 

omni 70mm ! cheap and like oem love it

 

Right. I was thinking/hoping a Maxbore'd ITR TB would be professionally done while keeping the OEM quality pulley/spring etc. But maybe all aftermarket plates have this problem?

Yes I was thinking the same but if I mess it up its junk.

Agreed. I cant imagine it being more than 5-10hp which is nothing considering I have no traction anyways. lol


How do I contact RPM Services? I want to ask them what I should do. I cant find a phone number or website.

 

x2

Going on 4 years now.... 74mm

 

Do you think this is an issue specific to the 76mm TB? I would like to borrow/buy a known good 74mm TB.

 

70mm RPM throttle body here

it works great... it use to stick but after cleaning it and soaking the spring it has been perfectly fine....

you could send it to maxbore.com and have it cleaned up with a new throttle plate

 

What did you soak it in? Maybe I need to lube it up.

 

Ive never liked too many aftermarket throttle bodies...

The Professional Products have always seemed good, and the Omni's as well.

Same casting as the Omni, with a taper bore from 74mm down to 70mm (69mm really)...I have had customers have great luck with these:

http://www.xenocron.com/throttle-body-74mm-p-374.html

I honestly dont know if you would loose any power going down to a 68mm or equivalent though...maybe a LITTLE throttle response, but like you said...traction is a bitch

 

To be honest I think 78mm is too big now. Sure I have great throttle response but at the cost of throttle modulation. Once I spool I can maintain full boost with only 50% throttle. I can't modulate it with the throttle. Like I said I hate my throttle body.

 

might be cause mine is a 74 mm also

 

The throttle plate is obviously touching the throttle bore so i would adjust the throttle stop ever so slightly to get it from resting on the bore.

 

have a customer with one of these and its a PITA too..... dont think ive ever used a throttlebody that sucked as much as the skunk2's.

ironically, the blox throttlebodys seem to work really well

 

how come the skunk2s get such a bad rep i have had no problems with my skunk2 68mm tbody

 

I have had several customers with "billet" skunk2 & blox tbs have sticking issues.
I have also seen issues with RPM services tbs on client's vehicles.

$99 omni power throttle body can't be beat for the money.
We keep them in stock for this reason :-)

 

Professional Products 68mm. Set it and forget it man, zero issues.