Autolite copper 104s... what gap?

tpivette89

Member
Joined
Mar 27, 2002
Planning on doing a plug/wire swap this weekend. Did some light research, and from what I gathered, the autolite copper 104s are the way to go for stock - bolton cars. Since these plugs are a bit colder than stock, do I need to close the gap from the factory spec of 0.060? If so, what gap setting is recommended? Or will they be fine at the factory gap?
 
an m90 car will be fine at stock gap of .060 or just under if you want to try closing them up a bit like .055 if you ever spray it or turbo it you would need to shrink the gaps. I personally run .060 on my plog/3.5/ 3" exhaust car that runs 13.5 @104 no spray for me - others swear by smaller gaps but i have had no issues with misfires that would indicate spark blowout. When I spray I drop gaps to .040 on my cars..
 
Thanks for the quick reply. I think i'll close the gap down to .055 just to be safe, since the 104s are a step colder than stock

One more quick question... I've seen the word "PLOG" tossed around numerously on this site... what modification does that refer to?
 
Thanks for the quick reply. I think i'll close the gap down to .055 just to be safe, since the 104s are a step colder than stock

One more quick question... I've seen the word "PLOG" tossed around numerously on this site... what modification does that refer to?

P log is short for powerlog , Powerlog is an item made by zzp that replaces your stock cast iron front manifold with a welded log style manifold that is lighter and flows better. the rear manifold is not nearly as restrictive since it is a welded tubular design from the factory and also takes well to porting

zzp makes them in mild steel and stailess steel for more $$ I had a mild steel crack at 13 months ,swapped to a stainless and no cracks yet after a couple years.

If you are going to start modding heres a few bits of advice from personal experience:

dont trust any of the performance packages from vendors every car is different in what it takes for supporting mods especially since most 3800 vendors are geared toward grand prix's that got 2 muffler vs. 1 on a regal gs. rely on people on the forums that have been through the starting modding stages themselves , they arent counting on you buying their parts to make a living..

dont think in pulley sizes and boost increases on L67's , pulley size will be dictated by suporting mods in place , elevation & temperature you run the car at ,available fuel quality , and your cars state of tune both ignition components and the programming that is in your pcm. you know what pulley you should be running only by scanning the car regularly to see if you are getting KR ( detonation/pre-ignition causes knock retard)

Also more boost is not always good on an sc car - if you add exhaust mods your boost should go down but make more power , high boost numbers on stock exhaust components means you are boost stacking - the number may impress your friends but it produces a lot of heat when it stacks which causes KR issues

if/when you do address pulley size buy a modular system (quick change) so you can change pulley sizes in a couple minutes to adjust for more mods , better fuel ( or worse) time of year ,etc... let the uneducated save $40 and buy a press on and be stuck withone size and have to mod & tune around it

buy used mods !! most of the basic mods to get these cars down into the 12-13 second range can be bought for around 60-75% of what they cost new and most arent parts known to wear much , if you want great results for short money dont be afraid to jump on a mod that you may not need until you get a few others in place first if the deal is right. $500 can get one of these cars in the 13's provided you are close to sea level and low to mid 13's for a grand using smartly bought used parts

learn all the mods you dont need such as tb spacers , aftermarket coils , ported front manifolds ,etc...

headers are the best exhaust mod to put in place that will compliment any & all other mods you will buy , if headers arent for you then a stainless plog/3" downpipe/intake/mps with 3.6 pulley/tune would put a big smile on your face-car will be night & day different and if it turns out you arent having KR issues when you scan it throw a 3.5 on it and let the games begin
 
Every car is different. On both my GTPs when there were mild bolt on cars I had run my Autolite 104s @ .055. Any higher than that I would get spark blowout. Also I recommend using stock or stock style Lifetime warranty parts house wires. I've had aftermarket wires and they don't seem to last. I run Borg/Warners from OReilly with a Lifetime Warranty and them seem to last a long time. I've replaced them twice in the last 6 years.
 
BTW, I strongly recommend a set of good headers over a ZZP Cheese Log errrrrrrrrrrr I mean power log any day of the week. There is minimal gains there plus in a year or two you'll be rewelding it guarannted. And for the price of a Power Log, Ported rear mani, 3" DP you're almost already at the price for headers so its almost foolish to go this route unless you plan on turboing in the future.
 
BTW, I strongly recommend a set of good headers over a ZZP Cheese Log errrrrrrrrrrr I mean power log any day of the week. There is minimal gains there plus in a year or two you'll be rewelding it guarannted. And for the price of a Power Log, Ported rear mani, 3" DP you're almost already at the price for headers so its almost foolish to go this route unless you plan on turboing in the future.

I fully agree a set of ss autochrome headers off ebay (slp knockoffs) for $300 is a better route and costs about the same or less than the plog/dp/ported rear route.... but due to personal experience I disagree about the minimal gains since I have run 13.5 @104 in my daily driver regal on 3.5/plog/ported rear/3" dp & exhaust /stage 1 tb/tune and not much else on street tires 2.2 60 foot close to 200k on the car at the time (214k now) and ran 13.9 stock size pulley (3.8 mps) same day same setup , stock long block including cam & rockers , no IC.

my headers /rockers/3.4/3.29 geared gtp ran 13.3 without spray and 12.2 @118 with so I have run both setups

13.5 pass on plog setup:

YouTube - Regal GS (13.5) vs GN

13.9 pass stock pulley/plog combo:

YouTube - Regal gs (stock pulley 13.9) vs GN

headers ,rockers ,3.4 spray gtp

YouTube - Murphinator vs Some Slow Ass Car

my quickest pass on the plog car was 13.1 @109 on a small shot (around 60)
 
Nice man, looks like you've had better luck than people I know. LOL I knew a guy who had a NICE set of PEMs (which I ended up running later for awhile till I went headers) and there were ceramic coated 2000 degrees and he was setup about like yours (3.4", PEMs, 3" Dp, no cat, tuned, ported TB) it ran 13.5s-13.6s... don't remember the MPH or the 60s. He switched over to a P-log and got it coated and it ran the same times and same MPH, never got any better than that. Then it cracked up and when to hell. Ended up getting Pace****ters and a 3.25 and going 13.2s. There was another guy here who had the same luck with the Powerlog, not much if any gains. I guess everyones luck and car is different.

I probably would of given the plog a shot but I ended up scoring a hellova deal on brand new TOGs for $500 so I went that route and never looked back. I never mind experimenting, look at my setup! LOL. I need a tune bad though, my base Overkill tune ain't cutting it, i'm halfassed tuned with an ICCU w/ happy knob. So yeah, I need a GOOD tune baddddddddddd.

Curious to hear more about your setup "murphinator". Especially the bolt on GTP w/ spray. Thinking about going w/ spray on top of what I got now, been thinking about it for a long damn time, just never have done it yet. I need a good tune first before I do anything, and I want 12s solid w/ what I got, then go for more. Not really interested in going too deep in the motor as far as heads and cam go. Post here or PM me, I'd really like to pick your brain a little, not many do nitrous on these cars...
 
P log is short for powerlog , Powerlog is an item made by zzp that replaces your stock cast iron front manifold with a welded log style manifold that is lighter and flows better. the rear manifold is not nearly as restrictive since it is a welded tubular design from the factory and also takes well to porting

zzp makes them in mild steel and stailess steel for more $$ I had a mild steel crack at 13 months ,swapped to a stainless and no cracks yet after a couple years.

If you are going to start modding heres a few bits of advice from personal experience:

dont trust any of the performance packages from vendors every car is different in what it takes for supporting mods especially since most 3800 vendors are geared toward grand prix's that got 2 muffler vs. 1 on a regal gs. rely on people on the forums that have been through the starting modding stages themselves , they arent counting on you buying their parts to make a living..

dont think in pulley sizes and boost increases on L67's , pulley size will be dictated by suporting mods in place , elevation & temperature you run the car at ,available fuel quality , and your cars state of tune both ignition components and the programming that is in your pcm. you know what pulley you should be running only by scanning the car regularly to see if you are getting KR ( detonation/pre-ignition causes knock retard)

Also more boost is not always good on an sc car - if you add exhaust mods your boost should go down but make more power , high boost numbers on stock exhaust components means you are boost stacking - the number may impress your friends but it produces a lot of heat when it stacks which causes KR issues

if/when you do address pulley size buy a modular system (quick change) so you can change pulley sizes in a couple minutes to adjust for more mods , better fuel ( or worse) time of year ,etc... let the uneducated save $40 and buy a press on and be stuck withone size and have to mod & tune around it

buy used mods !! most of the basic mods to get these cars down into the 12-13 second range can be bought for around 60-75% of what they cost new and most arent parts known to wear much , if you want great results for short money dont be afraid to jump on a mod that you may not need until you get a few others in place first if the deal is right. $500 can get one of these cars in the 13's provided you are close to sea level and low to mid 13's for a grand using smartly bought used parts

learn all the mods you dont need such as tb spacers , aftermarket coils , ported front manifolds ,etc...

headers are the best exhaust mod to put in place that will compliment any & all other mods you will buy , if headers arent for you then a stainless plog/3" downpipe/intake/mps with 3.6 pulley/tune would put a big smile on your face-car will be night & day different and if it turns out you arent having KR issues when you scan it throw a 3.5 on it and let the games begin


Solid advice here for any 3800 Series 2/3 guys out there. I know there few and far between here.
 
Iron Indian;2675589. Post here or PM me said:
the gtp is a car i bought modded to begin with , just sold it back to the guy I bought it from 2 years ago last night actually !

it has homemade fwi , 1.9 mod rockers , triple edge ported blower , togs , custom duals , dynotech trans w/3.29's , 42.5 injectors , mps w/3.25 & 3.4 - i used 3.4 on spray and ran 104 unleaded. I bought the car with intentions to demod it so I didnt care about the motor - I tried to kill it and couldnt dont try what I did on a motor you care about I sprayed it dry with a .76 jet which is probably nearing a 150 shot but on my regal I sprayed as small as a .35 shot and its a kick in the pants , non intercooled sc's love spray as long as you pull timing and run good fuel. I sprayed pre maf so the maf could see the extra volume of cold air as well as the IAT and enrichen for the spray. A wet shot/wideband combo is how it should be done , I am looking to head that direction on a car soon.

to tpi vette sorry for the thread jack bro :biggrin: hurry up and post more questions so we can get back on topic for you ;)
 
Haha no problem on the semi-jacked thread. Its all good advice that the new-to-L67 guys should know. Ive had pretty extensive experience with RWD V8 cars (TPIs, LTXs, LS1s), but this is my first FWD boosted car. Any good advice is welcome.

My goals for the car, performance wise, would be consistant high 12s. I live on the east coast, and race at near sea level. DA can fall into the negatives here during certain months, so track conditions are usually ideal for running good times. I even have access to Sunoco 100 octane unleaded at certaiin gas stations. All that adds up to a recipe for stellar results

So far Ive gathered I'll need some sort of CAI, stainless headers, a downpipe + catback, tune, DRs, and a modular pulley system. Assuming good DA and 100 octane, what size pulley would u guys think it would take to hit the number I'm looking for? Or would there be more involved? Any advice on what or where to purchase the required items would be greatly appreciated.

EDIT: found these on ebay... would any of these be a good buy or should I keep looking?

http://cgi.ebay.com/ebaymotors/97-0...ptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories

or

http://cgi.ebay.com/ebaymotors/OBX-...ptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories

also

http://cgi.ebay.com/ebaymotors/Pont...ptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories
 
My goals for the car, performance wise, would be consistant high 12s. I live on the east coast, and race at near sea level. DA can fall into the negatives here during certain months, so track conditions are usually ideal for running good times. I even have access to Sunoco 100 octane unleaded at certaiin gas stations. All that adds up to a recipe for stellar results

So far Ive gathered I'll need some sort of CAI, stainless headers, a downpipe + catback, tune, DRs, and a modular pulley system. Assuming good DA and 100 octane, what size pulley would u guys think it would take to hit the number I'm looking for? Or would there be more involved? Any advice on what or where to purchase the required items would be greatly appreciated.

you are light years ahead of most people modding these cars just in that you have the experience to know that you will meet your et goals on days with negative DA's , and understand the importance of proper octane.

The mods you are talking about now are typically associated with a 13.4-13.7 car , if you want 12's without gutting the car you will want to consider cam or rockers and full size intercooler which will typically require slightly larger injectors allthough not always.

or if e85 is available in your area go much larger on injectors and run a 50/50 blend or better and the chemical intercooler properties of the fuel could allow you to run a small enough pulley for cracking 12's but I havent done it yet due to the closest e85 is 2 states away from me currently

of course a small shot of spray on top of a mid 13's car can get you there also.


where 12's is your goal headers , 3" catback , intake , mps will all still be in place when you hit your goals they will be mods you can build around

there are several guys that have run 12's on a stock tranny but you will be on borrowed time... allthough if you went the nitrous route your trans would only be subject to all the extra power when you choose to spray it

I would lurk oven on club grand prix to see which of those ebay headers is currently working out best - I always get my mods from cars I de mod so I am out of the loop on which company of those is best though obx sounds familiar - those prices are great nowadays , I remember paying $425 for a set of togs with a crack in them about 3 years ago , many options now .

all these cheapie headers seem to have their quirks and need certain clamps & gaskets to get them installed leak free so I would pay attention to that also on the 3800 forums
 
Did a brief search on clubgp.com, looks like the ssautochrome are the best header value for the money. However, clubgp lists them as stainless steel, but when you look them up on their website, it says they're mild steel. Confusing...

Guess I'll have to ask around on clubgp to some of the guys who run them to find out for sure what they're made of
 
Did a brief search on clubgp.com, looks like the ssautochrome are the best header value for the money. However, clubgp lists them as stainless steel, but when you look them up on their website, it says they're mild steel. Confusing...

Guess I'll have to ask around on clubgp to some of the guys who run them to find out for sure what they're made of

I can answer that one for you , everybody asks that question and they are in fact stainless and exact copies of the slp headers , the mild steel is to throw off the copyright hounds lol
 
Nice! That answers that question. I was a little disappointed when I read that they were mild steel. Now I can order with confidence when I'm ready to do headers.

Right now I'm focusing on doing maintenance to it (filters, fluids, brakes, etc), then when Cecil County Dragway reopens in Feb/Mar I'll head down for some baseline runs. Once I establish that, the tinkering will begin.

I guess I have to do some more research to figure out which downpipe to get, as well as a decent catback that's Regal specific (single muffler). Thanks to all who've helped me so far.
 
guess i can share....lol

Well i guess it all started when i decided to resign the 86 T-type to weekend duty and needed something more docile for dinner dates out and whatnot... got an 04 CTS and was promptly rear ended and got an 03 Regal GS:D.
Took it to the local 1/8 mile track for some baselines and could hardly get the car out of the 9.8/9.9's @69mph. guess its ok for stock but...bleh!

Decided to jump in both feet first and went straight to replacing the stock manifolds for a set of headers...but WHOs... ZZP, Wbodystore, 3800performance, INTENSE, etc. And suddenly saw the Ebay OBX-R headers... oooooo SHINY! lol. Did a Google search on them and found the site... my first warning should have been the sites logo at the top of the page... "$hit is Good!" :rolleyes:. ooook lets try youtube and read some other import and domestic car forums about them. Forums uncovered a not too encouraging trend in the fitment and customer support for the headers of all makes. More imports than domestics...go fig :p. How bad could it be for only $200? Theyre Pacesetter clones and theyre so....SHINY and "new in the box" eeeeee!
They arrive and sure enough.....SHINY!!! But upon closer inspection INSIDE the tubing where the primaries meet and converge to one pipe....SLAG on top of slag, b..but theyre so....Shiny... Youtubed "OBX" and sure enough another unhappy trend was exposed under the hoods of all these OBX owners...the SHINY wasnt so...shiny anymore. Blue/purple/tarnish was the common theme. So went to pep boys and got the nice VHT ceramic 2600 Degree Black stuff in a can and took my shiny stainless headers into the back yard and Painted every nook and cranny til it was nice and coated. Next day took them to my mechanic with the car and a roll of header wrap for the crossover pipe under the throttle body for what little good that will do. A few hours later i get this phone call from a very tired sounding mechanic saying he cant get it to line up right where the crossover meets the front to the back. Seems the imports werent far off afterall. My poor mechanic had to cut the crossover in HALF to reclock it to get it to fit. guess the headerwrap was a good idea afterall lol. After that the fitment went fine...REAL fine! The original pacesetters come with clamps at the Y connection to seal them nicely...no such thing with these knockoffs because they figured it'd line up and fit so well that the seal requires no clamps! Well in the first few moments of the headers new life...it was true! Arrived to pick up the car and the sound reminded me of the very first moment i heard the T-type at the dealership. quiet rumble..unassuming. Then was told to take it for a test drive :biggrin:. I put the car in reverse to leave the shop, but theres a slight incline and give it quick tap of gas to move....bad idea for 125k motor mounts as the engine rocks and undoes the perfect seal under the car! now theres the sound of a bird fluttering under my hood...a LEAK!:mad:. little did i realize the fluttering was only the begining. ok track time!
This time took the car to a 1/4 track for any improvements. Did a decent 2.1 60ft. pulling a 14.75 @92mph....hmmmm lets look at the 1/8mile times...9.4 @73mph. heeey from 9.9s @69 to 9.4s @73's ..not bad for my first mod. But what the run also reveiled was that the engine SLAMMED metal to metal into its cradle or soft rubber mountings at the top of the track when i let off the gas. That cant be good! Poly mounts next!
Well...red ZZP poly uppers (just so u know they turn PINK later!) and dogbones AND lower mount later i snuck in a ZZP modular pulley swap to 3.3 since i already had a few supporting mods added while my mechanic was busy....NGK TR6's, 180 t-stat, K&N filter, and complete header swap with 3 inch downpipe and catless set up. I still have on the resonator and stock muffler...i like how QUIET it is! ....track time!
Arrived a little late to the same 1/4 track so i let the car semi-cool off by only 20-30 minutes and lined it up against a magnum RT hemi. :p. even with the car still hot it runs a 14.38 @95 :redface: 1/8 was 9.24 @75mph... not a Big improvement but i'm on to something and really ticked off the HEMI! Now I put in a ZZP pcm 1.0 and new Toyo proxes TQ 255/50/16 drag radials! track time!
went to the local 1/8 track and did my very first GS burn out:D
pulled a 2.03 60ft and an 8.80 @78.8! killing a nice 06+GTO AND a NEW 2010/11? 5.0 mustang with a supercharger!!! he "missed a gear" lol. NOW we're getting somewhere and going to the 1/4mile track tonight and hoping to have better numbers esp since its gonna be 47 degrees today! :eek: Hoping for mid 13's .. if not i think my tranny has been slipping somewhere lol. sorry for the rant.
 
nice sith !

they are sure easy to mod to that "next level" from there you gotta spend some money but still reasonable if you look at the real costs with most other platforms

the cheap headers do have fitment issues , people cheaping out on the headers deal with it like you have
3.3 pulley with your mods likely has some knock going on , next time out get as much unleaded race fuel as you can in it - not gallons thats weight but concentration of high octane to pump gas - I bet you pick up a solid couple tenths on that combo

you were very smart to make drag radials an early mod , traction will still be an issue on drs but dollar for dollar one of the best et reducers out there other than spray
 
I Couldnt pass up the deal on the Toyo Proxes TQ drag radials...only $134 a tire and the tread was radical enuff to be safe in a downpour at 80mph! course a 255 still looks a lil' funny on that stock GS rim. OH and we drove 90 miles to the palm beach raceway only to find out no test and tune....dam "NITRO JAM" event... bleh!
 
I see your in Miami , you need to hook up with Laz , he is on here and has been modding his GS daily driver , he has been involved in sone fast GN/t types also and Kshef thats on here in this section a lot has done track days with laz with his turbo'ed park ave
 
Yes I have Big Laz's number on my speed dial and even called to ask how the heck to make these cars do a burnout lol. Didnt know u couldnt footbrake these wrongwheel drive cars in the burnout box. Thank god the parking brake is a ratchet type XD! Takes a little practice to get it juuuuust right. Still the looks on peoples faces change from mirth to wtf wondering why a grandmas Buick "century" pulled up to the line...does a BURNOUT...then spanks the c.rap outta a few mustangs and GTOs is awesome!
 
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