I've been inquiring with ZZP since about mid-June on when they expect to be selling the PLOGs again. I just did a 2.5" DownPipe w/ High Flow cat (ver good mod) and really would like to finish my "exhaust" work with a PLOG (and I figure my $50 cat credit could go for a PLOG).

Every time I ask ZZP "We hope soon" is the answer. I'm gettin' ichy!! :-)

 

On a 3.4 setup, hardly any at all. The difference will get more pronounced with more extreme modifications. You'd be hard pressed to run a Gen V'd, IC'd, or cam'd car well with PEMs, but your basic ~300ish HP setup will really be the same with either.

For sure.

Yes, if you can verify that it's not cracked and isn't leaking. Ask the seller to confirm this, and ask for pictures around the primary/head flange surface- this is where the weld breaks and they leak.

Is it 304 stainless, or is it mild steel? I would NOT get the mild steel PLOG. These WILL leak- the 304 stainless may leak eventually, but it's not a guarantee.

 

Thank you. There not stainless so I'll pass. I only plan on doing what is needed to get the 3.4 pulley and won't go any farther and if its not much of a difference then I may just get the pems. Since the plogs tend to crack and leak, then at this point, their not worth the investment.

I can't make up my mind, lol. If I go PEM, do I need to get front and rear, or can I do just front?

 

I just did front... The stock rear manifold is actually pretty damn good. To me, it's not worth the hassle of pulling the rear manifold for the negligible gains. The biggest difference is with the front manifold.

 

I totally agree; between the release of the front PLOG, and brand new headers dipping below $300- they have become completely obsolete.

Honestly, that time is meaningless. There are people (especially those with turbo kits) that have went quicker on bone stock manifolds- but that doesn't mean they're not a restriction. Only way a 1/4 mile time and ET would be meaningful in this specific case is if you had before and after data with the only change being going from stock manifolds to PEMs, then to a PLOG/stock rear and comparing the differences.

Definitely very doable; especially on a 3.4" setup- and since you're already at 0 KR; you're already leaps and bounds ahead of the masses that still have a good bit of KR on the stock pulley at your mod level.

He doesn't need a cam either; but it would help lower KR. I think headers would be a great alternative. If you pick up a used set; he could sell his DP to get half the cost back; and be well ahead.


IMO, PEM's on the L67 are obsolete, and have been for a long time. First is the cost- usually when you find them; they're sold in sets (although I have seen places do just fronts)- but it seems like a lot of the used sets for sale come with both. Since the stock rear manifold is tubular, its not a restriction- and so half of the money you're spending is realistically for little to no extra gain.

Secondly with cost- look at the pricing; a single PEM seems to run like $50-80 used (brand new about $125); and a pair seems to run $75-125 (brand new about $150-190). A PLOG usually runs about $90-130 (brand new $180). Headers brand new start under $300; and used typically are all over the $200's depending on the brand (obviously much higher for some TOG big dogs or something like that). Plus with headers, you usually have some kind of downpipe connection included, so you save money on that too.

So a front PEM runs about 75% of the price of the PLOG with the same amount of labor to install- with less gains; why bother? May as well spend the extra $20 and get rid of the crappy front cast manifold (ever seen pics? its pretty bad inside). That's not even getting into the cost/hp ratio if you buy both PEM's- usually both PEM's + the price of a used DP = to headers, so that doesn't even make sense.

The argument for headers is you take the price of a used PLOG (say about $100) and the price of a used catless DP (also about $100)- and you're already more than 2/3 of the way to headers which are proven to have more of a power gain than a PLOG/3" DP. Sure install is worse with headers; but the difference in money is very small for the extra gain.

FWIW, I used to run a ZZP 3" catless DP and a mild steel (angled though) PLOG on my old GTP. I was very happy with the results, and never had cracking issues (just make sure you get the one with the angled primaries- not the ones that run straight up/down). However, I did not see the KR drop that some of my other college friends did who went straight to headers with similar setups.

 

Wow, now I really can't make up my mind, but thats for the awesome information. I'm still on the fence.

I don't know if I want to get involved with installing headers, they aren't much more but I'm a good mechanic and have a lift, torches, welder, ect...but I'm not good at fabricating.

Can you weld PLOGs if they crack since their not cast? If its repairable then it may be worth the investment.

 

Because the PEM is guaranteed to not fry your A/C condenser (like the PLOG did to my Regal) and isn't as crack prone, or because it's cheap and available. I went with the front PEM on my Monte because the PLOG killed my A/C on my Regal, and it cost me a condenser.

Just because they've been around for a long time doesn't mean they're "obsolete"- they are better than stock for sure and have their advantages. While I don't have dyno numbers or before/after 1/4 mile trap speeds, I can say that I was able to pulley down AND add timing after adding my front PEM.

You can weld them- lots of guys re-weld the primary to flange mating surface on both the outside AND inside of the primary- this is something that ZZP never bothered with. Alot of folks speculate that the single outside weld is a big reason they crack, and I don't know of anyone who welded the inside to have cracking issues afterwards.

 

Thank you. After going over the pros and cons off all, were going to get a front pem. Since all we want is to get to a 3.4 pully and the PEMS with rockers will allow for it, then were going to get a pem, and if we don't like it, then we can always buy a plog or headers down the road.

Thank you for all the help everyone

 

I'll be honest, I've never installed headers on a 6th gen monte- just a 5th gen, and some GP's. But IMO, if you have all that stuff, installing headers will be cake, its not that big of a project. Lots of people have done it to 6th gens, so its not that big of a deal.

Yes, as long as you have the correct gas/wire for the material (ie SS or mild).

I guess I'm confused what you actually had hitting- when I did the PLOG on my GTP, it didn't hit anything, and was nowhere near hitting anything. I've also never heard of this problem before (granted I'm only on Wbody forums)- any links to wbodys that have had this issue?

Maybe your motor mounts were worn out if the engine was moving that much? It really isn't that much bigger than the stock manifold.

I never said their age has made them obsolete. I said new product releases and their high cost for relative gains has made them obsolete.

The whole idea behind the PLOG was that the stock front manifold blows, ported or not- there are just some inherently bad areas. To me, its like trying to port out the downpipe to smooth flow around the u-bend. If you still have a nasty area; porting around it can only help so much. Being able to pick up a used PLOG for about the same as a ported manifold set is just icing on the cake.

Plus, headers are only a bit more money than a PEM set. Look at WBS- they want $190 for a set of PEM's brand new; when you can get headers (which include a downpipe) for under $100 more and have significantly more power gain.

Their high cost for relatively low gains is what made them obsolete; back in the day they were a great option - spend $150-200 for PEM's or $500-800+ for headers; today there are many more options that have closed that price gap.


Again, like the track time, its not really useful data- obviously any kind of porting or such will show an improvement, but it doesn't really help compare vs a plog or vs stock since there is no real hard data there.

 

Good choice- you'll love the car with a 3.4 pulley setup. My Regal is setup about the same and is a killer daily driver.

I just installed headers on a 6th gen Monte Carlo. It was a royal pain in the *** and not something I'd ever recommend to someone to do for a mild build.

Your definition of "not that big of a deal" is a bit skewed. You drove across a few states to pick up an L67 to put in a '96 Monte Carlo and then rebuilt it in an apartment. That is off the charts big deal, so I can see where to you installing headers on a Wbody isn't a big deal. To the rest of us, it sucks.

My Regal is a Wbody. The PLOG contacted the top of the compressor itself. I took some pictures back when I discovered it- if I can find them I'll post them...but if you've ever installed a PLOG on a Wbody, and I know you have, you know it sits really, really close the condenser. Since QC on the PLOGs was notoriously horrible, quite a few contacted people's condensers and broke their A/C. I was one of them.

If you don't think that adding boost and timing and raising the knock threshold is an improvement, then I really don't know what to tell you.