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95 Impreza L AWD
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Discussion Starter #1
My car is in the process of gettting a 5psi T-25 turbo on it, and I'm wondering if I should change plugs to a different heat range? I have the NGK BKR6E-11 plugs in my car right now. I know iSR has the 7 and 8 heat range NGK's, but is a hotter (assuming a higher number for NGK means hotter) plug what I want, or is colder better? I was thinking of BKR5E-11, but I'm not sure. Thanks! :)
 

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colder is better, since the A/F mix is going to be hotter due to the compression of the turbo (remember PV=nrT). if pressure goes up, so does temp. of course, the T-25 is pretty small (right?) and, depending on how much boost you're going to run and whether or not you have an IC, it might not matter.
 

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oops, you said you're running 5psi (i carn reed). so, it wouldn't hurt to run a range cooler, but i doubt it will matter that much. get a knock sensor and if you're getting alot of retardation, you might want to see if cooler plugs help.
 

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95 Impreza L AWD
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Discussion Starter #4
Thanks. I forgot to mention that I have a fender mount intercooler(I think it was from an Eclipse). The T-25 is tiny! I'd like to get a J&S but I don't have the money right now. I wouldn't know where to begin with a knock sensor, as far as what to wire it to and what not, unless it was a J&S. I'll probably get the range 5 plugs and see what happens.
 

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I dunno how much this applies because I have a VR6 but here goes.

The place I got my turbo kit from has also done a 2.5 RS turbo car. What I was told from them is that you always want a single prong plug for FI. They sent me Bosch F7DC's for the turbo. These are one range cooler than the F6DTC's that everyone with VR6's normally uses for FI.

If you wanna check it out, I think the Impreza is still on their site somewhere. www.matrixengineering.cc

:run:
 

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13 Years of RS
2005 Toyota Corolla :(
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PSI NRG said:
I dunno how much this applies because I have a VR6 but here goes.

The place I got my turbo kit from has also done a 2.5 RS turbo car. What I was told from them is that you always want a single prong plug for FI. They sent me Bosch F7DC's for the turbo. These are one range cooler than the F6DTC's that everyone with VR6's normally uses for FI.

If you wanna check it out, I think the Impreza is still on their site somewhere. www.matrixengineering.cc

:run:
Where are you located? I live not too far from Matrix (~10minutes), and one of the guys here at work told me about them, after he got a lot of work done on his VW. He's got a 90 Golf, I think, and he got the newer 1.8T put in to it, and atrix gave him a lot of help, I guess. I still need to go down there, and see what they have. It will be nice having them so close to home when I finish getting all my parts and start putting them on.
 

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I live near Cleveland Ohio.

I have one of the 2 VR6 turbo kits that they have shipped. I love it. All their work on the hardware is flawless, and everything fit perfectly. Josh and Jeremy are also very cool guys, and if you're that close to them, I'd recomend them in a heartbeat.

:run:
 

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95 Impreza L AWD
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Discussion Starter #8
Thanks! I checked their site, and they did a twin turbo 2.5 RS!!! I wish there were more pics of it! It seems like a pretty cool place! I guess what I should figure out now is how to "read" an NGK spark plug properly so I get the right thing!:)
 

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95 Impreza L AWD
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Discussion Starter #9
Ok, I went to NGK's website and found that a lower number on the plug equals a hotter plug! Therefore, I would want to go with the BKR7E-11 plugs rather than the range 5 plugs.
 

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If oyu email Matrix, they will usually get back to you the same day. If not the same hour. Really good guys.

I see you're from NW Ohio. Are you coming to the gtg at Headlands park this Saturday?

:run:
 

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95 Impreza L AWD
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Discussion Starter #11
Actually, I didn't know anything about the get-together! Where is Headlands park, as far as city and state? I don't think I have any plans for Saturday yet, but I may not have my car back, either.:curse:
 

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95 Impreza L AWD
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Discussion Starter #12
I found out where it is, so now I just have to see if I can get my car back and if I have anything else I have to do. Where are you from, by the way?
 

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do you guys know if the NGK platinum pfr70-11 will fit on our cars? i think i mighta bought the wrong plugs. by the way this would be for a turbo RS.
 

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95 Impreza L AWD
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Discussion Starter #15
I really couldn't say for sure. I guess the best thing to do would be to go to an auto parts store that carries NGK and ask if you can look at the catalog. The catalog will tell you how to read the number, so you can figure it out based on that, by comparing the stock number and the number you have and seeing if the thread pitches and what not match up.:)
 

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95 Impreza L AWD
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Discussion Starter #17
I don't know. Like I said, your best bet is to try and get your hands on an NGK catalog and that should have all the info you need.:)
 

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personally, i wouldn't run platinum plugs in a turbo'd car (of course, i wouldn't ever run them). remember, all they do is last longer. you get the best spark (within reason) from copper plugs. they just don't last as long. plus, i wouldn't leave a plug in any car, let alone one with an aftermarket turbo for 60k mi.
 

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I know this is an old thread but which plugs would be good for a non-intercooled ej25-t running around 5 PSI? There are no other engine mods besides borla catback exhaust. I looked up plugs for a 2001 rs on NGK's site but they didn't come up with any plugs for it.
 

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95 Impreza L AWD
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Discussion Starter #20
Probably NGK BKR7E-11 to start, then check them after a week or so; it you need to, go to the BKR8E-11. What kind of engine management do you have?
 
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