What are the best aftermarket pistons?

[1NaudiA4]

The piston ring on my number 4 cylinder broke so now I'm looking for some decent aftermarket pistons. I was originally going to just go with either some 8:5:1 or 9:0 mahles but there about 1-200 more than wisecos or je's.

What are the differences if any from Mahles, Wisecos, and JE's pistons?

Which pistons are rated for the highest horsepower?

I've been debating going the stroker route and just getting some aftermarket pistons considering my engine builder actually has a spare crank laying around his shop but I've decided I'd rather put that money into the head.

[onemoremile]

Mahle Motorsports are great but stock AEB pistons are nearly as good. The stock Mahle forged AEB pistons are good for more than that HTA30r will make. Nice turbo choice too.

[Don Supreme]

Did it ever run?

[mike-2ptzero]

Any of those pistons are going to be good enough for the power you want to make. I run JE's on my car and they seem to hold up well at nearly 800hp.

[1NaudiA4]

Yeah it ran great for the first 500 or so miles until I noticed I ticking noise that I thought was just lifter tick. I took it to my engine builder and 2 different shops and everyone thought it was lifter tick. After the tick started I noticed my compression was slowly but surely going down in cylinder 4.

All of my other cylinders compression were at 180 across the board and cylinder 4 was at 100.

Upon removal of the head I was able to tell that the top piston ring was half gone.

As for how the HTA30r performed I couldn't be happier. When the compression was good it was fully spooled by about 4300rpms.

I'm most likely going to run some 8:5:1 compression JE's.

-Mike, did yours come with any coatings?

[mike-2ptzero]

Yeah it ran great for the first 500 or so miles until I noticed I ticking noise that I thought was just lifter tick. I took it to my engine builder and 2 different shops and everyone thought it was lifter tick. After the tick started I noticed my compression was slowly but surely going down in cylinder 4.

All of my other cylinders compression were at 180 across the board and cylinder 4 was at 100.

Upon removal of the head I was able to tell that the top piston ring was half gone.

As for how the HTA30r performed I couldn't be happier. When the compression was good it was fully spooled by about 4300rpms.

I'm most likely going to run some 8:5:1 compression JE's.

-Mike, did yours come with any coatings?

No they didn't come coated and I didn't have them coated either.

[A4Rob]

I have the MAHLE pistons 8:5:1. Haven't installed them yet. Ill let you know

[Don Supreme]

Mike, why don't you warn him about the ring issue with the JEs?

[1NaudiA4]

Sean- Are you still going to go with the Mahle 9:0:1's?

[onemoremile]

Coatings are there for a reason. You could get by without them but I could get through day without pants too. Doesn't mean it is a great idea.

The skirt coatings reduce friction, heat and wear of both the skirt and the cylinder wall. Score the wall and the rings suffer. Piston top coatings help keep the piston from overheating but also limit the amount of heat transferred to the oil from the piston squirters. The underside coating helps transfer heat to the oil and helps shed the oil more easily.

The only coating that is remotely debatable is the piston tops. Some feel that it could lead to detonation or undue combustion chamber temps. In the real world that isn't a problem. Endurance race engines often have the piston tops and head side of the combustion chamber coated, often the face of the exhaust valve is also coated. They get the same power and better mileage which can mean a lap or two more between pitstops. On a street driven turbo car these coatings mean that more of the heat is sent to the turbo which can help lower boost threshold and increase spool rate.

[1NaudiA4]

Very interesting information on the coatings.

Correct me if I'm wrong but the Mahles come with the skirts coated?

[pac1085]

Another option is Wiseco. Not as many people run them, though. My Wiseco's look like nice pistons, the machine shop even commented on that. A friend has been running the same pistons in his 2.0 stroker for a little while now, and they are holding up. He's not making that much power yet though. I went with the ceramic coated dome and permanent anti-friction coating on the skirts. At over $700 they were not cheap though.

[mike-2ptzero]

Mike, why don't you warn him about the ring issue with the JEs?

Well any rings used can fail when the tune is bad or if the EGT's are much higher then they should be. It just seems they tend to fail a little quicker when these problems are there, but it does seem to be a "user" issue. If it was a huge problem the company JE wouldn't be nearly as big as they are.

[1NaudiA4]

Mike- What happened when your rings broke?

You just don't hear of rings breaking on the B5's to often. I definitely didn't feel any detonation so the only cause I could really put on the ring breaking is high EGT's or overheating. My AFR was between 11.5-11.7 at WOT. I really wish 034 put a output for knock sensors and EGT.

I'm for sure going to be getting EGT gauge now though.

[1NaudiA4]

Another option is Wiseco. Not as many people run them, though. My Wiseco's look like nice pistons, the machine shop even commented on that. A friend has been running the same pistons in his 2.0 stroker for a little while now, and they are holding up. He's not making that much power yet though. I went with the ceramic coated dome and permanent anti-friction coating on the skirts. At over $700 they were not cheap though.

The Mahle 8:5:1 pistons go for $659 from Bob and oh most $800 from 034!!

So I can basically get custom wiseco pistons fully coated for the price of the Mahles.

How much extra the coating run you and how much extra time to have them coated?

[creechsa4]

i run 9:1 82mm je pistons. you have to warm them up more than stockies in the am to get them to seal correctly. i remember the piston clearance to block was like .004 to .008. kind of loose compared to a stock piston clearance. i guess the je's expand a lot. not sure cleara nce on other brands, i've only used je's in all my vw/audi builds. i also run their je's gapless rings, they seal up great. I used to use total seal rings, but the je's rings are cheaper and work just as great imho...

[mike-2ptzero]

Mike- What happened when your rings broke?

You just don't hear of rings breaking on the B5's to often. I definitely didn't feel any detonation so the only cause I could really put on the ring breaking is high EGT's or overheating. My AFR was between 11.5-11.7 at WOT. I really wish 034 put a output for knock sensors and EGT.

I'm for sure going to be getting EGT gauge now though.

Only rings that I had break were the OEM ones on my stock rings, but that was after 85k miles and drag racing every weekend for 1.5 years.

My JE rings failed by losing tension causing me to lose compression in all 4 cylinders.


yeah a knock sensor would be nice. I have been running an EGT gauge for a long time but this month I bought the LMA3 to add onto my LM-1 wide band, this will allow me to log ETG, BOOST(only 2 bar though), injector duty, G force and RPM. I also went with the bluetooth option, this way I no longer need to connect the cable to view the LM-1 on my lap top or down load the files.

[t1demont1]

im selling a set of JEs 82mm with a 9.25CR for 600. Brand new in box. lmk ;)

[Don Supreme]

Sean- Are you still going to go with the Mahle 9:0:1's?

Yup and yes they have a light coating on the side..


Are you going to drill your exhaust mani for the egt probe?

Also, what did your timing advance look like? I assume you tuned it yourself?

[Don Supreme]

im selling a set of JEs 82mm with a 9.25CR for 600. Brand new in box. lmk ;)

I wish they came in under 9.25 off the shelf.

[t1demont1]

word, im getting rid of them cause I decided to go 2.0

[mike-2ptzero]

I wish they came in under 9.25 off the shelf.

Does 034 keep them in stock? Because they are listed at 8.5:1 on their site.

[1NaudiA4]

I actually already have a bung on my downpipe about 6" down from the turbo.

Heres a screen shot of my Ignition timing. It says its in demo mode because I unplugged it so I could hook up my laptop to the internet.

[djwimbo]

Mahle Motorsports are great but stock AEB pistons are nearly as good. The stock Mahle forged AEB pistons are good for more than that HTA30r will make. Nice turbo choice too.

What he said.
Stock pistons are made by Mahle, or are at least a Mahle design.
The pistons I pulled out of a customer's AWM were Mahle's, and coated. I believe most of the 1.8T pistons are made by Mahle and are pretty stout for stock pistons. The problem arises when you want to go to a larger displacement. As far as a personal recommendation, I can't give you one b/c I haven't built a 1.8T engine for performance.

We used a set of Mahle pistons in the LS1(same coating and metallurgy) we put in the Vette, and we were really happy with them. My only complaint is that between the 8 pistons we received there was almost 6 grams variance between them. I expected a matched set, or at least a set that was +/- 1 gram.

FWIW if I were to build a "1.8T" 058/06A engine I'd probably go with a set of Mahle's. I know a lot of people have had great success with the Weisco and JE though. Weisco made a mean set of custom pistons for my buddies turbo Capri, for a really good price. He ran a decent amount of power through that engine before the car itself couldn't handle it.

[Don Supreme]

I actually already have a bung on my downpipe about 6" down from the turbo.

Heres a screen shot of my Ignition timing. It says its in demo mode because I unplugged it so I could hook up my laptop to the internet.

So I must be reading this completely wrong or something, but it looks like this to me

@ 22 psi(or 157 Kpa) you are adding an additional timing advance of 5 degrees to your already SUPER SUPER SUPER DUPER high timing of 28 for a total of 33 degrees advance @ 6000 RPM?

I must be reading that wrong because I am surprised it didn't blow up the first time you went WOT! ahha

[mike-2ptzero]

I actually already have a bung on my downpipe about 6" down from the turbo.

Heres a screen shot of my Ignition timing. It says its in demo mode because I unplugged it so I could hook up my laptop to the internet.

You need to punch those into a spread sheet so you can have a 2D adv timing map. This is what I do so I can look at it when making changes to the timing.

So I must be reading this completely wrong or something, but it looks like this to me

@ 22 psi(or 157 Kpa) you are adding an additional timing advance of 5 degrees to your already SUPER SUPER SUPER DUPER high timing of 28 for a total of 33 degrees advance @ 6000 RPM?

I must be reading that wrong because I am surprised it didn't blow up the first time you went WOT! ahha

YOu are reading it wrong. Have to remember the KPA scale also include vacuum, so 22psi would be a bit higher up. To give you an idea, 32psi for me is right around 320-330 kpa. This means his 157kpa equals 15.7psi and 22psi would be closer to 2200.

So this means the ecu is pulling around 5-6 degs from that 33 degs, that would put him right around 27-28 degs at 6k.


On my timing map I am running 25 degs at 157 KPA and 6000 rpm, 33 degs at 8300 rpm.

[1NaudiA4]

So I must be reading this completely wrong or something, but it looks like this to me

@ 22 psi(or 157 Kpa) you are adding an additional timing advance of 5 degrees to your already SUPER SUPER SUPER DUPER high timing of 28 for a total of 33 degrees advance @ 6000 RPM?

I must be reading that wrong because I am surprised it didn't blow up the first time you went WOT! ahha

It really isn't that high. As a comparison heres a map from a gt3071r AEB

[Don Supreme]

You need to punch those into a spread sheet so you can have a 2D adv timing map. This is what I do so I can look at it when making changes to the timing.





YOu are reading it wrong. Have to remember the KPA scale also include vacuum, so 22psi would be a bit higher up. To give you an idea, 32psi for me is right around 320-330 kpa. This means his 157kpa equals 15.7psi and 22psi would be closer to 2200.

So this means the ecu is pulling around 5-6 degs from that 33 degs, that would put him right around 27-28 degs at 6k.

actually I think 256Kpa = a little over 22 psi, which would still have him @ 20 degrees advance @ 6K RPM? (Still too much for pump gas)

[Don Supreme]

The 3071 map looks a lot safer

Using same assumptions above:
~ 22.5 psi @ 6K = 15.5 degrees ( fairly safe. )

[mike-2ptzero]

The 3071 map looks a lot safer

Using same assumptions above:
~ 22.5 psi @ 6K = 15.5 degrees ( fairly safe. )

The first picture might be the demo readings not his actual maps. He should have snapped the picture while still connected to the stand alone, then unplugged to hook up to the internet.


Added, no those are his readings. Just opened up the software on my lap top and the demo just shows 1's in all the boxes.

[Don Supreme]

On my timing map I am running 25 degs at 157 KPA and 6000 rpm, 33 degs at 8300 rpm.

tuned for 104, or did you bump those numbers for 110?

[AudiA4_20T]

me and Jake (ssayarc317 or however u spell it) have been running Wiseco 9:1 CR 83mm pistons for awhile. They held up fine even to my blown headgasket and his tuning issues.

[1NaudiA4]

Definetely going to hop on a dyno this time and get the tuning/timing perfect.

[mike-2ptzero]

tuned for 104, or did you bump those numbers for 110?

That was tuned on 110 on the dyno.

[Wizard-of-OD]

JE's are pretty good pistons.I have sold over 200 sets between the Audi & VW community (and counting) and I wouldnt sell a product if I didnt believe in it.

The Mahle's are also amazing but getting custom bores & CR's is a PITA.Anything over 82mm...you are looking @ JE's.
I would go coated skirts and FRS option