cpi throttle body and injectors

[scrape]

anyone know where i can get a larger after market cpi throttle body? ive had no luck finding any for the early cpi engines.

also how about injectors b/c i know you have to buy the funny spider looking deal to replace them, but does anyone make one with larger injectors, or is there a way to replace just the injectors?

 

[mattw]

Re: cpi throttle body and injectors

The throttle body is not removable.. Its molded right into the upper intake.. If you were creative you could prolly cut it off and weld on a flnage that would accept a LS1 TB.. I have no idea on the injectors.


-Matt

 

[jjorgensen52]

Re: cpi throttle body and injectors

anyone know where i can get a larger after market cpi throttle body? ive had no luck finding any for the early cpi engines.

also how about injectors b/c i know you have to buy the funny spider looking deal to replace them, but does anyone make one with larger injectors, or is there a way to replace just the injectors?

So far as I know the CPI injector can't be adjusted. I think if you updated to the later style it uses a regular injector to feed the system and I imagine that could be updated. The other option is to weld in some injector bungs and put real injectors in there, but that is a much more considerable project, because you need to swap the ECM and repin the whole harness

I'm going to be modifying a CPI intake this weekend to accept an LT1 style TB, and then modding a late model CPI vortec lower intake to accept the old style upper. I will be posting details sunday.

 

[scrape]

Re: cpi throttle body and injectors

so if i were to switch the upper out with a later model, would i have to replace any sensors or other electronics or would it be just a straight swap?

 

[jjorgensen52]

Re: cpi throttle body and injectors

so if i were to switch the upper out with a later model, would i have to replace any sensors or other electronics or would it be just a straight swap?

From what I have seen, up until 2001 or 2000 they used the same wiring, single injector setup. After that they swapped it to some other bizzare thing with one large injector feeding six smaller ones

 

[jjorgensen52]

Re: cpi throttle body and injectors

We started adding the new TB
http://www.syty.net/forums/showthread.php?p=417621#post417621
check it out :tup:

 

[SonomaGTlover]

Re: cpi throttle body and injectors

The CPI injector CAN.. I repeat can be adjusted but it is not recomended. I adjusted mine up just a little but it already puts out 50-60lbs or so. Been awhile since i worked on it so I don't remember too well.

Also note that I said injector, there is only one that feeds the 6 lines to the cylinders. I found that leaving the original setting worked best for me so just replace it with a new unit and work on creating more air flow. I noticed about 1.5 sec gain it he 1/4 switching to vortecs and headers.

If you want bigger injectors it can be converted to a fuel rail and seperate injectors (I know a guy that did it succssfuly) but I'mnot sure about the ECM. You'd probably have to go to a SYTy ECM and learn to tune. I will probably do this in the upcoming years adding a small turbo but I haven't worked any particulars out yet, just ideas.

 

[midnightbluS10]

Re: cpi throttle body and injectors

From what I have seen, up until 2001 or 2000 they used the same wiring, single injector setup. After that they swapped it to some other bizzare thing with one large injector feeding six smaller ones

That ended with the CPI engine. 96+ have 6 smaller injectors where before that it was one injector with 6 poppet nozzles.

This is a pic of the injector assembly inside of a CPI unit.

Here's one of the lines on the injector assembly itself.

and here is what you find in the later 96 and up 4.3's

Way different.

pictures from http://www.lindertech.com/reconinj.htm