Plog!! (power log thread)

I understand that keeping it out of WOT will lower the chance of knocking, but believe it or not, I've seen slight KR in OD at low RPMs. Usually this is when going up a hill, but it does happen. You are in boost a lot when cruising in OD. On a steep grade, locked in OD, you could see significant knock using a 3.4" pulley. You also can see KR at partial throttle, and during downshifts.

Same thing with low octane fuel. It kills me to hear of people driving around using 89 or even 87 octane. They think if they don't go WOT they're fine. Wrong! I can use 89 oct to drive from Columbus to Cincinnati because it's flat, but to Cleveland - no way. I tried it once. Got between 1-5º KR CONSTANTLY every time there was a slight grade on the freeway. Just shows how much difference the terrain can make regarding the load presented to the car.

Not saying your 3.4" is making lots of knock, but you just can't know. I was knocking with a 3.4" for a whole year before I got the scanner and found out what was going on. Whatever you do, run premium always for added insurance!

I ONLY use 93 octane, and have never put anything less (not even 92).

It's funny you should mention it, I'm actually going down to Columbus (actually Delaware) today. I guess I should stay out the the hills on my way back, which is damn near impossible.

If you run 93, it should be fine. Our motors are strong, they can take a little ping. Knock isn't that dangerous in small amounts, but I prefer not having it at all. I just wanted you to know, your engine knocks sometimes when you are out of WOT, and sometimes you can go WOT (1st gear) with no KR at all. Only way to know is to scan.

If you can drive to C-bus, I'll let you use my AutoTap so you can see what's going on.

Perhaps... it's only 20 or so minutes away. Except they removed the first Wendy's ever, which sucks.

I'll let you know if I can stop by.

I don't get out of work until evening, so just let me know.

AA wrote:

I understand that keeping it out of WOT will lower the chance of knocking, but believe it or not, I've seen slight KR in OD at low RPMs. Usually this is when going up a hill, but it does happen. You are in boost a lot when cruising in OD. On a steep grade, locked in OD, you could see significant knock ....

Low throttle in OD and 3rd is considered high load. This is an easy place to see knock even without a pulley swap. Something that opened my eyes was a friend mentioning.. "when you see KR, remember that is the pcm reacting to knock after it's already happened".

Any KR in my opinion is bad. Low amounts occasionally are better than constant..but still bad. Who can tell when that last little bit is too much.

Installed my Powerlog and ceramic crossover today.Forgot to take the donut style gasket off the old crossover.So I kept getting exhaust leak.It was LOUD.Kept trying to tighten and realign but still no luck.Almost was on my way in to have you guys tell me were I went wrong when I decided to take it apart and compare it with the old one.Found that donut gasket and now everything is great! Next is my Hogan downpipe and catalytic converter.

Excellent, progress is good! I still don't have my coated crossover installed, just the Plog.

1998 Riv wrote:

Excellent, progress is good! I still don't have my coated crossover installed, just the Plog.

I didn't go with the ceramic coated Plog , I think it would have looked a lot better than the SS Plog into the ceramic crossover.Still a huge improvement over stock. Again , thanks for all the advice Dave,Its been extremely helpfull . JIM

HEY, found a free 30 minutes to install my coated crossover this morning! Getting the back 2 studs out was a bit of a bitch, but I soaked them good with PB Blaster first, and they gave in. Found the 2 front bolts were none too tight, but I don't think it was leaking there. Anyway, applied a little anti-seize and installed ZZP's piece and it looks great. Hopefully it also helps move more heat out of the engine bay and off the TB.

Nice. Hope it seals okay. What type of clamps did you use? Any use of sealant at the joints?

OEM clamps, no need for anything else. Donut gasket at the back was in good shape, reused it. The front is already formed to fit tightly, just made sure it lined up good then tightened it all down. Really a perfect fit with the Plog.

If you didn't know, the coated crossover is just a stock piece.

After install , i did notice a bit more power up top. Not a huge difference , but less of a drop off in the 5k+ rpm range. I think i had to many mods on the induction end to really see the benefits with my 3.4 , 4" intake and ported blower , engine seems happier up top. I paid only 75+shipping for the ceramic coated plog ( used ) so i'm pretty happy with it. No leaks this time either.

Do you have any previous scans to compare MAP, MAF, and KR levels before and after the install? Glad you see a difference up top. It's exactly what our engines need!

Yes , i'm about to go do some scans right now to see what everything looks like and maybe get some tuning in. I was hitting 10k+ in my MAF before , and about 11 PSI with no KR , but we'll see if boost has dropped and Ive picked up maf. If fuel trims are still good , i'll try and add some timing again. ( running stock timing right now)


I wouldn't say the difference is night and day , but it is noticeable. Not so much in the seat of your pants as in the needle sweeps a bit quicker between 38-46 now.

Quote :

I wouldn't say the difference is night and day , but it is noticeable. Not so much in the seat of your pants as in the needle sweeps a bit quicker between 38-46 now.

That's expected. You won't feel it in your seat. If you're seeing even a small increase above 4kRPM, I think the P-log is a good investment.

If you like the way that needle moves, and you want to see it really go, try rockers!

So i did some scans I saw 10.4 PSI at the shift on one run and for the most part i see 9.5 psi on others , and it was cooler out this run than the last run and i still lost about 1lb of boost. I don't think this a normal drop in boost , but it makes it tempting to pulley down no. My LTFTs are also showing pretty lean right now , sometimes getting as high as 7 or 8 , so my fueling will need to be retuned. No knock anywhere those which is good. I think after i get my tune in again i'll be able to run plenty of timing , or even pulley down to a 3.3 come winter with cooler temps.

Also it is louder at WOT. Not obnoxiously loud , but louder.

Those rockers look like fun , but right now i gotta catch up on some bills and buy a few books for school. Maybe january after i get my christmas bonus.

I'm curious to see what i'll run in the 1/4 this winter.

Excuse my ignorance, but after reading all six pages I still don't quite know what a Plog is! I know it's not not a PEM or a Header, so what exactly is it??? And what are the benefits and cost?
Thanks

http://www.zzperformance.com/products_img/208_1.jpg

It's a simplified header segment that will bolt to the stock crossover pipe, in place of the factory manifold. In performance terms, It flows substantially better and it's a lot lighter. A true header flows a little better still because the primaries remain independent through the first bend.

A plog is basically a stock manifold replacement. NOT a header. The stock manifolds are highly restrictive, the Plog opens things up to let the exhaust flow a lot better. Not as good as a true header, but a good improvement over stock and over a PEM.

1998 Riv wrote:

A plog is basically a stock manifold replacement. NOT a header. The stock manifolds are highly restrictive, the Plog opens things up to let the exhaust flow a lot better. Not as good as a true header, but a good improvement over stock and over a PEM.

Can you elaborate? does this have something to do with the collector flow, price, power?...my next big investment is the exhaust so..."throw me a bone...need the info"

It has everything to do with flow, price, and power. The stock manifold is $0, and flows adequate for 240 HP. The Power Log is attractively priced, flows more exhaust gases, is easy to install, and lets you build more power than stock. True headers are expensive, more difficult to install (not too bad, though), and allow almost limitless room to develop power.

It's kind of like this:



Stock mani is more renstricted, plus power pulses collide in shared collector. Power Log is less renstricted, but power pulses still collide in shared collector. True header primary provides less restriction + the pulses are separated, resulting in less backpressure.

In short, headers flow best, but the Power Log a step better than the stock design because it uses a larger collector. It should be noted that the stock rear manifold is designed more like a true header, so this is why you only need to use a single Power Log. I have seen 3800 engines that used a custom header for the front, leaving the rears stock.

If I had to guess, I'd say stock manis are good for 240-275 HP, Power log = 250-300 HP, and headers 280 HP and up. These numbers represent how much power you could make with other mods, and which exhaust design I'd use for each range. If you plan to make 400 HP, headers are a given, but if only wanting to add 10-20 HP, headers are a waste of $, imo.

What about ported exhaust exhaust manifolds would they be a good upgrade for a stock engine?

I suspect ported & polished stock manis would fall somewhere between stock manis and a Power Log.