Possibility to make 500whp without having to do bottom end. b6/b7 s4

Theoretically it’s possible, but it would also probably grenade your BHF shortly after that. Stage 1 is already maxed out at the safest level possible. That’s why any more power than that, it requires a built bottom paired with their hd heads. I personally wouldn’t risk it just for a little more power. Risk to reward ratio is not in your favor.

What do you think would cause it to blow though? The valves?

Here is where all the walls fall down. We have a great motor but only to a point. The JHM kits make about 450whp and are good for a solid 11.x pass very close to what you would see out of the much more potent RS4.

But here is where things fall apart. The issue with our motor isnt actually the rods. Its the pistons. The pistons if pushed too hard will expand at a faster rate then the cylinders. This is one of the major reasons behind doing piggies as it helps remove cylinder heat faster. So the pistons expand too quick and then the get trapped in the cylinder and bam the rods snap at the neck where they are the weakest.

You can just replace the piston but the rods have a serious neck down at the wrist pin and that makes them weak. So its pointless to change the pistons and not the rods or not the rods and not the pistons. You can change both of them but that will also depend on how good your cylinder walls are as if you make too much power you will just push the walls out. Thats why JHM has to go through all the hassle of trying to put in cylinder wall support even with the sleeves

http://audirevolution.net/forum/index.php?topic=2270

This guy did his own built motor with JE pistons and Payter rods. Haven’t seen him post in forever though.

Now what do I do if the JHM tune doesn’t get rid of the CEL? I think I’ve seen one person still have a CEL after piggies and tune but I can’t seem to find that thread again.

What CEL do you have? The JHM tune does not delete the rear O2, so if it’s actually bad you will get a CEL.

Exactly. The JHM tune will help let the car know it should expect extra air flow for no cats but if you have a damaged or bad 02 it will give you a code. To say it differently if you have bad equiptment you will get a code if you just have a free flowing exhaust you wont have an issue

Oh okay thanks, I’m just trying to figure out if it ever happens when I get it done. It will be on the shop taking off my DP and putting them back on if they damage it to get a code?

SO I’m getting my piggies done tomorrow at a shop, whats the time I should expect for the removal of my DP and gutting and install again? Also, what should I expect when I get my car back besides a CEL? Increased power? Or does that only come after a tune?

Torque response
“Harder pull” from the V8
Throaty metallic V8 noise
Smiles…lots of smiles.

Add in JhM91/93 and you’ll wonder why it didn’t come like this straight from factory :laughing:

I read that a lot haha but I’ve always thought i needed a tune for the car to learn what I did to it. I for sure am getting a 91 JHM tune in a few weeks not right after piggies so hopefully that will be okay but I plan to fill up 94 even with the 91 tune but have the 91 just in case because I know it will adapt. Whats the shop time for to get it done? I don’t wanna pay an outrageous time on it. My B7 is also auto so I know it will take longer than a manual S4

For someone to remove and gut the pre-cats, no more than an hour per pipe; entire job should be no more than 6hrs, at least three hours minimum. It shouldn’t take a qualified shop 6hrs to do…

I gutted my main and pre-cats in about two hours for both but that’s because I took my time then add in about 3hrs to reinstall/mount. I’m pretty anal/OCD about things so i generally double the time a shop can do things.

Awesome thanks! I saw a bunch of DIY and I woulda done it myself by taking them off would be the hard part, gutting looks hella easy. Hopefully this shop doesn’t take 6 hrs lol It took me 2 weeks to get in so they must be good… Their shop rate is $110/hr thats gnna be over 600 if it takes them 6hrs haha

I’ve got cracked downpipes causing a leak… Awesome… Now I have to either go aftermarket or find stock ones to gut them myself. Should I look at aftermarket options? Or stick with stock ones? I found a set local for $350 he said he took them off at 70,000Km so its still pretty new.

My gutted piggies are coming within the coming week but I don’t know how pressed you are on time; see if he’ll take it for $250.

Those are OEM DPs or are they aftermarket?

Idk how bad the crack is because the shop didn’t show me but what could be the cause of the cracked downpipes? Also, the DPs he has are manual and I have a tip so they won’t fit… It looks like I have to wait for a set of stock tip DPs and risk whatever happening with this crack OR order aftermarket ones right away. What after market ones are available thats relatively a good price thats also 2.5"?

JHM? Can’t justify 1200 US which comes out to like 1400 CDN for downpipes before shipping
Milltek? 860 was the cheapest I found for them before shipping as well.

Any other brands I’m missing that could work? I searched AZ but nothing.

Be careful with millteks…I had 2.5" milltek DPs and for whatever retarded reason, they necked down to 2.25"…of course you can cut the tip off and weld on 2.5" connectors.

Another solid choice would be trexturk DPs if you can find them. I don’t know if he’ll still make them but you can always send him a PM via Audizine (I don’t know if he’s registered here).

Then there’s the classifieds for used FI DPs; I saw a set here a while back but don’t know if it’s been sold or not.

If their necked down to 2.25 there really is no point of them… I read somewhere recently that he stopped making them. So i’m almost SOL unless I dish out some money. Any other options?

I think I might have just bought the set on the classifieds you’re referring to.

I hit up trexturk on instagram back in March and he said he would still make downpipes then, so unless something has changed since March you might be in luck

Whoops my bad, I misread. I did not buy the FI DPs on the classifieds, I bought the catback. Someday I will be able to edit my posts…