carace

I must agree with Mike O. I went through the same thing he has except I had no scraping problems. I continued to use that setup(my car is a Passat) until I changed my exhaust layout when I upgraded to the APR stage III. I would not recommend TAP to anyone that was other than a bitter enemy.

Žob

Not mine, but someone else....

Hi all,

need some help scoping out cause, ideas, costs, options to fix re a '92 UrS4
motor meltdown...

This concerns the moto/speedvision cup '92 S4 purchased from TAP (1st big
mistake was trusting TAP). The car arrived from Florida, with supposedly
"fresh rebuilt 440-HP" engine*. However, right off the truck, it was
blue-smoking some, was missing lots of high-HP parts, such as the RS2
injectors and MAF. Replaced the stock injectors and MAF with RS2 units,
fixed multiple intermittent-faulty sensors, tightened a finger-loose knock
sensor, finally got it running OK. Did a leakdown test re smoke, but test
was OK. Suspected hybrid turbo oil seal leak at this point. Decided to run
the car despite
variable amounts of blue smoke that appeared for a few minutes at some but
not all startups.

Argghhhh!!

At PIR event, don't know the cause, but a valve head broke off, and bounced
around at high velocity, in #2 cylinder.

- The cylinder wall is scratched a little but easily salvageble with honing
etc. there is no wear-lip at top of cylinder at all.
- The piston is badly eroded and 1/3" holed, thus metal bits distributed
throughout engine
- The head chamber is chewed up and eroded pretty bad. Either get a new
head, or do major welding to add material back + machining salvage job?
- looks like oil/melted-aluminum slurry went through the hot side of the
T4-K27 turbo, but blades may be OK, needs more looking into, at least
cleaning.

Situation: After about 20 minutes of the Audi PIR event track session, car
had completed a nice strong pull up to neighborhood of but not beyond 7000
rpms, pulling hard and smooth_right _through to the braking point about
115mph (definitely below rev-limiter), lifted off gas for PIR turn #1, onto
brakes hard down to 50mph or so, went to blip gas for downshift, surprised
by hardly any/no engine rpm response. coasted through PIR's chicane, felt
like motor was in "limp mode", then there was a sudden 100 yard plume of
dense blue smoke out tailpipe. turned off ignition and coasted onto grass
behind flag station. No fluid leaks or smoke at that point. (With full-face
helmet on and noisy race car sound level, never did hear any mechanical
distress sounds.) Note: always used 104 octane unleaded fuel. Topped off
with synthetic oil, good oil pressure.

I suspect that the valve train was somehow weak, or very race-used before
it arrived, or put together wrong perhaps, and cumulative stress somehow
caused the valve failure at a fairly random moment. Usually this kind of
valve failure is caused by a severe over-rev +_immediate-failure at the
exact moment that over-rev occurs. Absolutely not the situation here, so its
a bit mystifying as to the _exact cause. (Also not a lean fuel/detonation
piston-punch-thu) Would like to figure out cause.

Clark@turbo5.com

COST on that Cat is $650 bucks.. Thats just for the Cat. That cat is a 3.5 inch 3WAY race cat that is used in europe. Then add the Stainless pipe and labor to tig weld that together. There is a bend so it must be mandrel bent. Then the unit is polished. Add Gaskets.. Beleive me.. We do not make much on that item.

Look.. I agree that $840 is alot for a cat and down pipe. But, It is the best Piece available at any price for your car. It flows more that ANY other system and does NOT throw codes. We import those cats from Europe. They are used in racing and are rated for 650hp each. I tested about 5 Cats before finding one that did not throw codes. Most aftermarket cats are garbage in my opinion. They have slow fire off time and throw codes if mixture is not perfect. Its one thing to get a cat to not throw codes around town. Its another on a 500 mile trip through the mountains and the desert. I found a unit that would not throw a single code for weeks of normal driving. After an hour of highway it would toss codes left and right. You get what you pay for.

Clark<ul><li><a href="http://www.turbo5.com">http://www.turbo5.com</a</li></ul>

Leszek

Specifically:
1) Does the downpipe have a flex piece like the stock one and most aftermarket do.
2) For people with an aftermarket downpipe (such as the ones who bought the borla exhaust) do you offer just the cat?

xr4tic

It is a very nice piece, but I personally can't justify the cost per HP gain, especially when I can make my own for much cheaper.
Plus, I've already heard a couple of people say they have had no problems with other cats.
Maybe the older ECUs are less sensitive?

Even mounting the stock cat further downstream would provide an improvement due to the turbulent exhaust (it spirals) coming out of the turbo, giving it time to smooth out.

xr4tic

Thanks, looks like I have my christmas break project now

jbrhino

Gentlemen your input is sincerely appreciated, thank you

Rich L.

I was on the straight approaching the chicane when the "plume of dense blue smoke" was dispensed just ahead. Quite a cloud. It was sad to see it go home on a flatbed.

Rich

carace

I will second that. Even that piece of junk that TAP sells with thier kit never caused a DTC on my car.

Clark@turbo5.com

The Turbo5 Cat/down pipe just replaces the stock cat. It bolts to the turbo and then to a Borla or other down pipe.

Clark<ul><li><a href="http://www.turbo5.com">http://www.turbo5.com</a</li></ul>