Guys humor me a little here - I realize this is far beyond my normal scope, but could you tell me how much of a difference you're talking here about retarding/advincing the timing based on the plug???? Without any real knowledge here I'd have to think you're talking miliseconds or even nanoseconds difference.
Not trying to be a smart ass - just curious.
Thanks
Racin'Jacin
1998 C5 Roadster
Moderators: MostMint, wxo, Fred32v, Basement Paul, ttamrettus
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Racin'Jacin
- Posts: 354
- Joined: Tue Oct 28, 2008 11:01 pm
Spark plug
Last edited by Racin'Jacin on Sat Aug 08, 2009 1:55 pm, edited 1 time in total.
RJ, remember that the statement was made by a GM trained tech. His advice was based on his education, training and experience. He stated that he has experienced the effect of changing plugs on detonation and explained why. If this is true, with the detonation sensors on modern engines and how they can cause a change in the timing under the covers, I can see then, how performance would be effected by plugs. The question of "how much" is up for grabs, however. Until I learn differently and have a good reason to stray from his advice, I believe that following this recommendation would be prudent in my situation.
I don't know. With 54k on the clock, I assume they are whatever the factory put in. The car has been running like a fine sewing machine, but I have a set of the latest recommended plugs waiting in the wings for a day of wrenching. I have no real reason for changing them except that I'd like to know the condition of the old ones and also will have a known quantity in the replacements.
My first thought was - "something is broken" - and I was expecting discussion about odds sounds from the engine bottom end. Then I thought - talk about a set up line!GMJohnny wrote:I have a bit of concern about my bottom end.
There are some things they can't fix at Hutter.
[quote="Basement Paul"]Is that a mint rocketship on the hood?? :shock:
-BP[/quote]
-BP[/quote]
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Basement Paul
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I've met and worked with several certified "technicians" that don't know sh*t about tuning a car. Because he's a GM tech doesn't necessarily mean he really knows squat about tuning. Most of these guys are just robot parts replacers looking to make good on their flat rate, and want to spend as little time as possible with your car.
I'm not saying this particular guy doesn't know, but being GM certified doesn't mean he does either.
-BP
I'm not saying this particular guy doesn't know, but being GM certified doesn't mean he does either.
-BP
Like I said earlier, I know this guy personally and he does good work and knows his stuff. He is or was active and accepted in the Corvette community. The only question on the table is how significant is the performance impact of not using the factory specified plugs on LS1 motors. I doubt we can answer that here. I just thought it was interesting to think about and discuss.
To throw another wrench in the gears of the conversation, I saw nothing but NGK boxes at Hutter performance the other day. Also, WXO sported me a free set of NGK's when I got my Vette. I am due to go back to Hutter's next week, I will ask them what their opinion is. ( Not that they are the gospel either, but may put an interesting spin on this. ) As someone who is trying to go fast and is possibly in need of a plug change, I am interested in installing the best plug possible. I will report later.....
Finally made it back to Hutter's today. Trevor did some more tweeking on the computer to try to help out the bottom of first gear. When I take the vette to the track next, we will see if he helped it. It feels better, I think, but whenever you hop up your car it "feels better." The track will tell. I also got some info about spark plugs from them. Trevor says he has had nothing but good luck with NGK plugs. He also said he could not say anything bad about AC Delco plugs. He made a point to say that ( listen to this WXO ) they gap the plugs in the LS1 motor at .035, not the .055 or .060 or whatever stock is. He said on supercharged motors they recommend .025 - .027 gap. When my plugs go in ( NGKs ) they will be at .035.....
That's interesting, John, because the paragraph below looks like GM's newest recommendation for plugs for the LS1. Note that the gap has changed to .040 inches.
A new spark plug has been released for use in the above vehicles. The new spark plug has an Iridium tip instead of the current Platinum tip. Due to the different tip design, the gap of the spark plug has also changed. The new spark plug, P/N 12571164 with AC Delco P/N 41-985, is gapped to 1.01mm (0.040 inches) when the spark plug is made. The spark plug gap is set during manufacturing and should not be changed or damage to the spark plug may result. Any new spark plug found to not be properly gapped should not be used.
A new spark plug has been released for use in the above vehicles. The new spark plug has an Iridium tip instead of the current Platinum tip. Due to the different tip design, the gap of the spark plug has also changed. The new spark plug, P/N 12571164 with AC Delco P/N 41-985, is gapped to 1.01mm (0.040 inches) when the spark plug is made. The spark plug gap is set during manufacturing and should not be changed or damage to the spark plug may result. Any new spark plug found to not be properly gapped should not be used.
So I am just finishing a 5 day vacation. During this time, I was able to finalize some of the work I have done this last month. I started to concentrate on some of the interior detail that was not correct. It started with replacing a broken center console latch,( pictured below ) which I purchased from my local GM dealer. I then replaced the center console top, which was in good shape cosmetically, but had a wear dent in where your elbow rides. My right elbow was sore after any amount of time in the car. I bought a complete console on ebay, and must have done something correctly, because I sold the whole console with my old top on it for $30.00 more than I paid for it. It looks great as the picture shows, and AHHHH, no elbow dent!! I also replaced a broken carpet hook, the convertible hatch lid strut, and re-painted one of the heater control knobs where the white flaked off. Finally, I replaced the old, weather-beaten visors with an inventory overstock ebay sale. $100.00 for both GM visors, new in plastic. The car, after over 3,000 miles and a little over 1 year of ownership, is continuing to be a great play toy, and I feel I am making it better along the way. Now I think I am going to start the tedious task of detailing door jambs, trunk, under hood, etc.... All to get it ready for winter!!
So the other night I was out picking up my daughter from a friends house, and I decided it would be the correct fatherly thing to do and do a powerbraking burnout in the middle of a paved back road. It was fun and my daughter was laughing histerically as the car ( with traction control off ) was getting sideways well into second gear. As the car shifted into 3rd, a loud exhaust sound was heard. I gimped home sounding way louder than normal, only to find that the weld on the exhaust pipe that connects to the flange that holds the pipe to the tail pipe was broken. Ugh!! I am trying to get ready to go to the track Wednesday. So after a quick phone call to Fred32v, we had a plan. I ran to work and grabbed the mig welder and Fred cruised over to be the pipe holder. We had the pipe secured in a snap. ( It will be replaced by an x-pipe kit at a future date, I have been looking for an excuse to purchase one, now I've got it )
So, as not to end a fun night to early, We changed the throttle body to a ported one I purchased used on ebay. These are supposed to help the throttle response, and add 5 hp. Some say more, but I am always doubtful until I see numbers on a slip. At the same time, I made a throttle body coolant bypass, to keep the radiator coolant out of the throttle body.
Hopefully these modifications get me one step closer to the 12's. I am praying tonight before I go to bed for cold also!!! Pictured below are the two throttle bodies, the one with the thicker outside lip is the stock unit.
So, as not to end a fun night to early, We changed the throttle body to a ported one I purchased used on ebay. These are supposed to help the throttle response, and add 5 hp. Some say more, but I am always doubtful until I see numbers on a slip. At the same time, I made a throttle body coolant bypass, to keep the radiator coolant out of the throttle body.
Hopefully these modifications get me one step closer to the 12's. I am praying tonight before I go to bed for cold also!!! Pictured below are the two throttle bodies, the one with the thicker outside lip is the stock unit.
So, after a good night at the strip, I netted a 13.09 @ 108.44 & a 2.01 60 foot time. That was a decent ending to the season, but..... I seem to have this wavering of the throttle at start and at idle sometimes, especially when I fire up the car cold. What was bizarre at the track was that 2 of my runs were almost identical ( the other a 13.10, same mph ), but several were 13.20's & 13.18, but the mph was off. I think this may have to do with the fact that the throttle body is a-miss. Perhaps a bad throttle position sensor, or throttle body plate drive motor. I am going to change both as soon as I get a free second. ( I have the parts off of the old throttle body.) I also managed to score a bassani xpipe assembly (NOS) and a used Z06 intake from Hutter's on Wednesday. I got good deals on both, paying $400 for both pieces. I have seen the intake go for around $300, and a new pipe for $325. Those, unfortunately, will probably be winter projects, and I am going to try to slap in a set of 1.85 ratio rockers & valve springs this winter too. Then to the shop for a tune, and hopefully the 12's next spring.......
Well, last Sunday, I found a free second & changed the throttle position sensor. That cured the wavering rpm condition. I found some info on the internet that makes me think the sensor that was on the throttle body I got was from a car with a large cam. Anyway, problem solved.
Today, I had a bit of free time, so I decided to go after the x-pipe. According to everything I read this was an easy install. The install calls for cutting the stock pipes & sliding the x pipe over the stockers, and band clamping them on. No welding necessary. What they failed to mention was that the spread on the x pipe was not wide enough to accept the spread on the stock pipes. I was a bit stumped, so I visited my speed friends at Hutter Racing, who gave me a hot tip on pulling the pipes together. "A ratchet strap should pull them together," they said. They were right. They told me that was a common problem with these pipes. Good thing they were there, because it worked like a charm. After that fooling around, the pipe fell into the car. What a difference in sound and feel inside the car. Before the x pipe, the factory H pipe would allow a popping, unsmooth feeling, which rattled the floorboards. I have none of that now. I think it is also faster, but, as I have said before, it always feels faster when you make modifications. Perhaps I will have to go to the track one more time before the car gets stored.
This post was brought to you today by the letters "H" & "X" and by the number 2 1/2 ( inch pipe ). Note also the red exhaust contracting tool, not available from your local snap-on man.
Today, I had a bit of free time, so I decided to go after the x-pipe. According to everything I read this was an easy install. The install calls for cutting the stock pipes & sliding the x pipe over the stockers, and band clamping them on. No welding necessary. What they failed to mention was that the spread on the x pipe was not wide enough to accept the spread on the stock pipes. I was a bit stumped, so I visited my speed friends at Hutter Racing, who gave me a hot tip on pulling the pipes together. "A ratchet strap should pull them together," they said. They were right. They told me that was a common problem with these pipes. Good thing they were there, because it worked like a charm. After that fooling around, the pipe fell into the car. What a difference in sound and feel inside the car. Before the x pipe, the factory H pipe would allow a popping, unsmooth feeling, which rattled the floorboards. I have none of that now. I think it is also faster, but, as I have said before, it always feels faster when you make modifications. Perhaps I will have to go to the track one more time before the car gets stored.
This post was brought to you today by the letters "H" & "X" and by the number 2 1/2 ( inch pipe ). Note also the red exhaust contracting tool, not available from your local snap-on man.