CPR turbo What jets do I need to start with

[Rx1M5]

CPR GT25 on an RX1 running at 6-8000 feet usually just below freezing temps. What jets should I install for the first and if I get really lucky last time. I have a wideband coming but I have the carbs off now so I might as well take a shot at it and get close. On here for different applications I've seen guys using everything from 120 to 140. Exhaust will dump in the tunnel.

Thanks Rx1M5

 

[Trxster]

I think you would start with 127.5's but since you are dumping the exhaust directly you could fatten them up a bit. I did not notice much of a change when I had my exhaust direct but then I am running the glasspack which isn't much resistance anyway. I'd probably start around 130's and come down from there (always better to be rich and give up a little power than be lean and get a little ping). Also depends on how much boost you run but if you are planning 10-12 psi I think that should work.


Rt

 

[BlueByYou2000]

Id start a bit richer than Trxster recommends. 132.5-135 then get your readings. Jet down from there. I rather error on the rich side than the lean side. I ended up running 132.5s all winter and my stoich readings were dead nuts...BBY

 

[Trxster]

Id start a bit richer than Trxster recommends. 132.5-135 then get your readings. Jet down from there. I rather error on the rich side than the lean side. I ended up running 132.5s all winter and my stoich readings were dead nuts...BBY

Don't you ride at low elevations???? I agree, start rich....I started at 135's, then went 132.5, then 130, then 127.5 and finally 125. I really enjoyed pulling everything apart that many times.

 

[snowy1]

Trxster: are you running an o2 sensor, if so what kind of readings are you getting, when I had the gt25 I had to go up to 135 at 10,000 ft. tried lower jets but it was way too lean.

 

[BlueByYou2000]

Id start a bit richer than Trxster recommends. 132.5-135 then get your readings. Jet down from there. I rather error on the rich side than the lean side. I ended up running 132.5s all winter and my stoich readings were dead nuts...BBY

Don't you ride at low elevations???? I agree, start rich....I started at 135's, then went 132.5, then 130, then 127.5 and finally 125. I really enjoyed pulling everything apart that many times.

Yes i do ride at low elevations. This certainly needs to be taken into consideration. I didnt notice in the original post what elevation he was at...BBY

 

[Trxster]

Trxster: are you running an o2 sensor, if so what kind of readings are you getting, when I had the gt25 I had to go up to 135 at 10,000 ft. tried lower jets but it was way too lean.

I do have the 02 sensor and my readings are not right where everyone else may be. I have the MCX front mount and am not sure I like the IC but at 135's I was bogging hard at WOT at about 9.6 and had to lower my needles all the way just to get the thing to run on the mountain (5000ft). When I got down to 125's I was running about 11.5 but it was warm out so I figure when it's cold I'd be running around 12 with the 125's. I have the 28g so it may be different but you should probably call Dave @ Powderlites for his recommendations but I believe he told me 127.5 for mountains is what they run at around 12psi.

Rt

 

[snowy1]

Trxster: are you running an o2 sensor, if so what kind of readings are you getting, when I had the gt25 I had to go up to 135 at 10,000 ft. tried lower jets but it was way too lean.

I do have the 02 sensor and my readings are not right where everyone else may be. I have the MCX front mount and am not sure I like the IC but at 135's I was bogging hard at WOT at about 9.6 and had to lower my needles all the way just to get the thing to run on the mountain (5000ft). When I got down to 125's I was running about 11.5 but it was warm out so I figure when it's cold I'd be running around 12 with the 125's. I have the 28g so it may be different but you should probably call Dave @ Powderlites for his recommendations but I believe he told me 127.5 for mountains is what they run at around 12psi.

Rt

It seems that every sled runs alittle different, may be that mine wants alittle more fuel due to the fact I don,t run a hood and everything is alot cooler all the time, I am running alot bigger turbo now so it wants even more fuel.

 

[Rx1M5]

I should have asked for the needle positions, fuel screws etc while I was at it. Any ideas?

Thanks