NGK TR7ix Spark Plug First Impressions

[Lance SVT]

So after reading through several threads from you guys on here, I decided to swap out my current NGK TR6 spark plugs for some colder TR7ix iridium plugs. I did not gap them at all, and just threw them right in out of the box like what was reccomended. My car is an 03 Cobra with a Kenne Bell 2.6H running about 15psi of boost. As soon as I fired the car up I could immediately tell it idled smoother (not that it was bad before) but I could definetely feel a difference. Now the main reason I swapped over to these plugs, was because I was getting a misfire feeling when I would shift gears under load at lower rpms. I was thinking it could be one of several things such as the pprv valve. But I came across some threads on here with people having the same issue, and swapping over from TR6's to TR7ix's took care of the problem. Well I gave it a shot and so far I am impressed! Like I said previously, the car already idles smoother, but it also shifts through the gears just fine without any hesitation! What impressed me the most, is it seems like it pulls smoother and harder under wide open throttle! All I need to do now is go for some more drives to confirm the results, but so far so good

 

[01yellercobra]

How many miles were on your old plugs?

 

[Black02GT]

I agree the IX plugs let you run a larger gap helping idle and low load (lean) driving. The stock gap is big (.038) it worked fine on 93 but on E85 it was having trouble lighting the mixture some times. Ended up switching to TR6IX and lowering the gap to .30 and fires like a champ now and still a smooth idle. I definitely prefer the IX over the regular TR yeah they're twice as much but plugs aren't something I change enough to care about another $25.

 

[CobraBob]

I've never heard of a gap issue with the regular TR6 plugs. I've heard of plenty of folks using a lower gap (.028 for example) with these plugs. The regular TR6 plug is the most popular for good reason. Inexpensive and they work. JMO. Here is a good thread to read. Lesson On Plug Gap For High Boost

If you like the IX plugs go for it. It's an excellent plug. Just pointing out the the TR6 plug does it's job extremely well. And because they're so inexpensive you can change them more frequently without breaking the bank.

Also, never assume the factory gap is correct. Always check the gap to be sure. I once installed a set of IX plugs and 4 out of 8 had a larger gap. Probably doesn't happen very often, but I learned that it definitely can happen.

 

[Blueline]

I switched out my TR6 that only had dyno time and a few hundred miles for TR7IXs. and felt a huge difference. Im a big fan of the Iridium plugs.

 

[Bigggy]

I've never heard of a gap issue with the regular TR6 plugs. I've heard of plenty of folks using a lower gap (.028 for example) with these plugs. The regular TR6 plug is the most popular for good reason. Inexpensive and they work. JMO. Here is a good thread to read. Lesson On Plug Gap For High Boost

If you like the IX plugs go for it. It's an excellent plug. Just pointing out the the TR6 plug does it's job extremely well. And because they're so inexpensive you can change them more frequently without breaking the bank.

Also, never assume the factory gap is correct. Always check the gap to be sure. I once installed a set of IX plugs and 4 out of 8 had a larger gap. Probably doesn't happen very often, but I learned that it definitely can happen.

X2, always check the gap. These plugs comes out with a very large gap and need to be gapped down. It is even more important with a bigger blower with more boost.

 

[Lance SVT]

How many miles were on your old plugs?

I believe about 2-3,000 miles. When I had my car tuned, the tuner put in some fresh ones before the dyno session. I'm not sure what they're gapped at though, I'll have to go back and check.

I agree the IX plugs let you run a larger gap helping idle and low load (lean) driving. The stock gap is big (.038) it worked fine on 93 but on E85 it was having trouble lighting the mixture some times. Ended up switching to TR6IX and lowering the gap to .30 and fires like a champ now and still a smooth idle. I definitely prefer the IX over the regular TR yeah they're twice as much but plugs aren't something I change enough to care about another $25.

So far I really like them! Only time will tell, but I am really impressed so far! I called around, and Napa had them for the cheapest at less than 7 bucks a plug!

I've never heard of a gap issue with the regular TR6 plugs. I've heard of plenty of folks using a lower gap (.028 for example) with these plugs. The regular TR6 plug is the most popular for good reason. Inexpensive and they work. JMO. Here is a good thread to read. Lesson On Plug Gap For High Boost

If you like the IX plugs go for it. It's an excellent plug. Just pointing out the the TR6 plug does it's job extremely well. And because they're so inexpensive you can change them more frequently without breaking the bank.

Also, never assume the factory gap is correct. Always check the gap to be sure. I once installed a set of IX plugs and 4 out of 8 had a larger gap. Probably doesn't happen very often, but I learned that it definitely can happen.

Thanks for the info Bob! I bet they're both awesome plugs since it seems like a lot of people run both. It just seems like the TR6's are more finicky with finding the right plug gap for your application from what it sounds like. I like the fact that I can run a colder plug with more gap and it runs really smooth! True the TR6's are a lot cheaper, but I really don't put enough miles on my car to be changing them out that frequently. I just figured I'd give these plugs a shot since if heard nothing but good things, and so far I am glad I did!

I switched out my TR6 that only had dyno time and a few hundred miles for TR7IXs. and felt a huge difference. Im a big fan of the Iridium plugs.

Nice!!! I am right there with you, I noticed an immediate improvement as well!

X2, always check the gap. These plugs comes out with a very large gap and need to be gapped down. It is even more important with a bigger blower with more boost.

Thanks for the advice! I didn't check that gap with a gauge, but I did however look them all over before I put them in and they all looked consistent to me.

 

[vrt03cobra]

What' the part# for the TR7ix plugs? I'm going to try out a set, I always use TR6's and know that part# by memory
(4177).

 

[Lance SVT]

What' the part# for the TR7ix plugs? I'm going to try out a set, I always use TR6's and know that part# by memory
(4177).

It's #3690. The cheapest I found them for was at my local Napa auto parts store. http://www.napaonline.com/Catalog/C.../Spark-Plug-Iridium-IX/_/R-NGO3690_0275392952

 

[Bdubbs]

I had spark blowout with tr6ix gapped at .030 on 17 psi. Went back to tr6 gapped at .028 and a 04sleeper tune and it's smooth as butter. I really think my engine runs smoother on e85.

 

[Lance SVT]

I had spark blowout with tr6ix gapped at .030 on 17 psi. Went back to tr6 gapped at .028 and a 04sleeper tune and it's smooth as butter. I really think my engine runs smoother on e85.

Hmmm interesting. I wonder if it's because of the e85 vs pump fuel. If I had my choice I would go the e85 route, but the nearest location that has it is an hour away. I'm just running Oregon 92 octane premium and after two drives the results have been great so far! Here soon I plan on jumping up to 18psi once I get bigger injectors, so we'll see how these plugs act with that set up. Looking at my old TR6's that came out of my car, the gap looks pretty large, so I don't think the tuner ever gapped them out of the box. The TR6's are suppose to be at .052 out of the box vs the .040 of the TR7ix's.

 

[Strikeking10]

I put TR7ix's in my car also Lance, I gapped them down to about 28 though, it idles smooth but now I have lower commpression in #'s 5 and 6 so ill be tearing it apart this winter

 

[Lance SVT]

I put TR7ix's in my car also Lance, I gapped them down to about 28 though, it idles smooth but now I have lower commpression in #'s 5 and 6 so ill be tearing it apart this winter

Oh man I'm sorry to hear! Such low miles too! Are you still gonna drive it, or just wait and rebuild it?

 

[Strikeking10]

Oh man I'm sorry to hear! Such low miles too! Are you still gonna drive it, or just wait and rebuild it?

It doesn't have a problems driving and still made 568 on the dyno but ill probably only drive it a couple more times then rebuild it, I have my new f150 I can drive while its down

 

[jltcai]

I currently have tr6 in mine...mostly stock , gapped at 32 and they are way better than my last plugs...dont laugh please...e3 plugs...im glad i read on here that there were way better plugs. Anyway im gonna try the tr7ix next as i have heard plenty good about them.

 

[Lance SVT]

It doesn't have a problems driving and still made 568 on the dyno but ill probably only drive it a couple more times then rebuild it, I have my new f150 I can drive while its down

Gotcha Cody. I would still drive it too man, especially since you just got done with the blower swap.

I currently have tr6 in mine...mostly stock , gapped at 32 and they are way better than my last plugs...dont laugh please...e3 plugs...im glad i read on here that there were way better plugs. Anyway im gonna try the tr7ix next as i have heard plenty good about them.

Nice man! I don't think you can go wrong with either style of plugs. I just know that the TR7ix's are a lot less finicky with plug gaping. The way I look at it is like this, anytime you can get away with running a cooler heat range plug go for it! Also, the TR7ix's are made of iridium vs copper on the TR6's. Well our cars came stock with iridium plugs, so that tells you something.

 

[jltcai]

Thanks for the input

 

[vrt03cobra]

It's #3690. The cheapest I found them for was at my local Napa auto parts store. http://www.napaonline.com/Catalog/C.../Spark-Plug-Iridium-IX/_/R-NGO3690_0275392952

Cool! Thanks man.

 

[Stage 4.6]

Ive been running these TR7ix for about 2 years they have about 9xxx miles on them and have worked really well. I cant remember exactly but I think I gaped them at 28? I have a similar set up to Lance SVT with the exception of Kooks LTs. My car has had at least 3 dyno tunes since installed, should i consider replacing them soon?

Also my car just recently developed a very slight stumble at idle (more like a faint popping sound) but runs fine under acceleration and wot with no hesitation, could this be the plugs or gap causing the slight stumble at idle?

 

[Weslsew]

Does anyone use the TR6ix or do you all just use the TR7ix? Do they have the little pieces on them like platinum plugs? I've steered clear of platinum plugs since I changed the plugs in my sisters 4.0 mustang and half of them were missing the little platinum pieces.

I use the TR6 and love them, but they don't last long. But they're only like $1.50