RBC Swap Questions

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323

Modifier
5,252
3,684
Chicago
Vehicle Model
Civic Si
Body Style
Sedan
Hey guys,
I'm doing an RBC swap soon and i've been reading a lot about it but still have some questions i hope you can answer.
I'm planning to get the one from PRL

First, would it be worth it to upgrade the injectors at the same time? Would they really make a difference?
- If so, which ones would you suggest?
Second, is it worth it to upgrade the throttle body?
- which one?
If i stick with the stock throttle body, does that mean i'll have to get the TB inlet bored?
Last, any other parts i would need?

Thanks
 
If you keep the stock throttle body you don't need to bore the manifold. If you get the ZDX throttle body, I would suggest having the manifold bored to match the larger throttle body opening. If you can afford it, I would definitely suggest the ZDX throttle body. Injectors are not necessary unless you plan to do anything more than simple bolt ons. I don't plan on doing anything else, so I had the RBC's injector openings machined to accept the stock injectors. If I ever do anything more, there are ways to upgrade the injectors.
 
JAYBLS said:
If you keep the stock throttle body you don't need to bore the manifold. If you get the ZDX throttle body, I would suggest having the manifold bored to match the larger throttle body opening. If you can afford it, I would definitely suggest the ZDX throttle body. Injectors are not necessary unless you plan to do anything more than simple bolt ons. I don't plan on doing anything else, so I had the RBC's injector openings machined to accept the stock injectors. If I ever do anything more, there are ways to upgrade the injectors.
Click to expand...
Thanks, that helps a lot.
What's the benefits of the zdx TB?
 
Bigger inlet and outlet. The ZDX inlet is 78mm compared to the stock, which is like 65mm (I think).
 
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Stock is 64.5mm if I'm not mistaken. The ZDX, I believe, has a 78mm inlet and a 70mm outlet, which is why you would want to have the RBC inlet machined to 70mm: to match the outlet of the ZDX throttle body.
 
JAYBLS said:
Stock is 64.5mm if I'm not mistaken. The ZDX, I believe, has a 78mm inlet and a 70mm outlet, which is why you would want to have the RBC inlet machined to 70mm: to match the outlet of the ZDX throttle body.
Click to expand...
And that makes a big difference? I can't imagine that 12mm does that much
 
Lol guess I was wrong, I'll probably have to get it now. Thanks everyone
 
woah,with the TB total comes out to be $764.95
there goes a paycheck lol
I'll have to do this when it gets a little warmer :)
 
Yeah, the ZDX is not cheap. You can also get a J35 throttle body which is half the price of the ZDX, but it's also a bit smaller in size and a good upgrade to the stock tb.
 
It's $780 shipped for the RBC, ZDX, 70mm bore inlet and stock 9th gen injector machining (at least it was shipped to Jacksonville, FL). The thing is, if you hold off on the throttle body, you'll have to order another throttle body adapter when you eventually do get the ZDX TB. If the throttle body isn't worth it to you, don't worry about it. I almost got the RRC intake manifold, but it just wasn't worth the extra money so I opted for the RBC. You may find yourself in a similar situation with the throttle body.
 
JAYBLS said:
If you keep the stock throttle body you don't need to bore the manifold. If you get the ZDX throttle body, I would suggest having the manifold bored to match the larger throttle body opening. If you can afford it, I would definitely suggest the ZDX throttle body. Injectors are not necessary unless you plan to do anything more than simple bolt ons. I don't plan on doing anything else, so I had the RBC's injector openings machined to accept the stock injectors. If I ever do anything more, there are ways to upgrade the injectors.
Click to expand...


It really depends if you are *thinking of upgrading the injectors in the future. PRL's kit already comes machined for RDX 410cc injectors and the RDX injectors are being offered for $220. PRL also offers the service to enlarge the injector bores of the RBC manifold to fit the larger style 2012+ stock injectors for $100. If your not planning to upgrade the injectors, then you should just save yourself the additional $120 and re-use your OEM injectors.


IF you decide later down the road that you'd like to upgrade to larger cc injectors then be prepared for a headache. This is because you chose to use your OEM 2012 injectors & then you paid PRL to enlarge the injector bore diameter so they fit. (Essentially you saved yourself $120 cause you didn't upgrade at the time). Now, if you've already done this, then the regular RDX injectors or 8th gen injectors will not fit ! Until some company comes up with larger cc injectors that are the same size as our 2012+ injector bore then you do not have the option to upgrade... cause they don't exist yet.

The point im trying to make is that if you enlarge the bore of your RBC manifold, there is no going back. Why not just purchase a new larger performance part for $220 (RDX), than spend $100 to permanently mod your manifold to only work with inferior and lower performance OEM injectors (only because you decided to save 120 bucks?... plus guarantee'd yourself that you can't upgrade for the time being?)
 
Um...I don't see why. All you'd need is bigger o-rings in theory. It really can't be that challenging from an engineering standpoint to put a smaller injector into a larger hole.
 
Well yeah your right...you can upgrade when you wish to with a fix. PRL has already found the right grommets to place on the RDX size injectors in order to fit the manifold with enlarged bore (2012+ injectors). To upgrade you would need to purchase new injectors and grommets + you've invested 100 in the machining.

This route is useful for those who don't frequent the forums, if they have already spent the money to enlarge the opening then this would be the fix to enlarge the diameter of your aftermarket injectors.

Im trying to let people know that if you have the opportunity before hand, it would be wiser to upgrade the injectors now and not bore. In the long run it is less cost and you maintain the original re-sell value of the manifold (to another 9th gen owner)


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Fair enough. I had mine machined because I wasn't planning on doing anything else performance-wise, but mainly because I didn't want to cut my factory harness. If I do decide to go turbo in the future, hopefully they'll have PnP injectors for our cars.
 
Honestly, either route you go with will work. if you bore out the manifold for the stock injectors, you can save the money from having to upgrade injectors. It DOES NOT limit you in the future to what injectors you can run. as SGTmecca posted, we have seals to do RDX injectors in the larger 9th gen injector bores. these seals work on pretty much any bosch or denso injector, so it really doesn't limit you to what injectors you can upgrade to in the future. However, if you are absolutely ready to upgrade injectors at the same time, the of course skip the boring service and go with the RDX injectors or ID's, DW's etc. In an ideal world, it would be best to do everything at once, i.e. manifold, injectors, zdx throttle body, 3.5" cold air intake, flashpro, downpipe, and exhaust. We understand that is not an option for everyone hence why we basically set it up to build your intake manifold kit the way you want. We just want to make sure that everyone understands that even if you bore it out for the stock injectors you are not limited in the future should you decide you want/need to upgrade injectors.

as far as the throttle body, we can always bore the manifold out as well, and you can still run your stock throttle body for now. it would save having to pull the manifold back off and send it to us or port it yourself in the future. our adapter for the stock throttle body will work on a ported out manifold as well as the stock manifold.
 
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prl motorsports said:
Honestly, either route you go with will work. if you bore out the manifold for the stock injectors, you can save the money from having to upgrade injectors. It DOES NOT limit you in the future to what injectors you can run. as SGTmecca posted, we have seals to do RDX injectors in the larger 9th gen injector bores. these seals work on pretty much any bosch or denso injector, so it really doesn't limit you to what injectors you can upgrade to in the future. However, if you are absolutely ready to upgrade injectors at the same time, the of course skip the boring service and go with the RDX injectors or ID's, DW's etc. In an ideal world, it would be best to do everything at once, i.e. manifold, injectors, zdx throttle body, 3.5" cold air intake, flashpro, downpipe, and exhaust. We understand that is not an option for everyone hence why we basically set it up to build your intake manifold kit the way you want. We just want to make sure that everyone understands that even if you bore it out for the stock injectors you are not limited in the future should you decide you want/need to upgrade injectors.

as far as the throttle body, we can always bore the manifold out as well, and you can still run your stock throttle body for now. it would save having to pull the manifold back off and send it to us or port it yourself in the future. our adapter for the stock throttle body will work on a ported out manifold as well as the stock manifold.
Click to expand...


I was gunna pick up a used rbc im from ya - just wondering - if I was to get it without the service to fit my 9th gen injectors - would injector adapters work just fine??? with my 9th gen injectors...like these http://www.powerrevracing.com/product-p/p364.htm

thanks!
 
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