Difficulty to install/replace downpipe?
 

I'm seriously thinking about replacing the downpipe and testpipe with turbo tim's 3" units. How difficult is it to replace the downpipe?

Any opinions as to which should be done first. Test pipe and downpipe or cat back? I'm leaning towards the test pipe and downpipe as that will yield the largest gain by far..

The car has the stock k26/8 with the only mods listed below.

thanks,
Adrial

Do the testpipe and it is one of the few easy mods on our cars.

3.0" T304SS mandrel bent catbypass pipe - performance downtube and a set of Chips tuned to no cats are always the 1st horsepower modifications for any 944Turbo anywhere in the world. performance for the next millenium

uhh, but how difficult is it to replace the downpipe? :)
Also, what kind of gains should I expect from upgrading from the stock downpipe to turbo tim's 3" downpipe? Mods listed below. By gains, I mean HP gains, reduction in turbo lag and reduction in full boost RPM.

thanks,
Adrial

To replace the downpipe you will have to remove the turbo which means removing the intake manifold. Tim should be able to advise you on what each of the sections will do and what order he would recommend if you are not replacing the entire exhaust.

Geoff,

You are thinking of the crossover pipe, the cat pipe comes off easy, 3 nuts at the turbo extension pipe,2 at the wastegate and 4 at the catback you get to all of them from under the car. Easy unless they are rusted. :)

Dave Floyd, I think what we mean by Downpipe you mean by "turbo extension pipe" :)

...still undecided on the downpipe...SFR didn't know what the benefits would be with a stock K26/8...I'm leaning towards just the 3" test pipe and 3" catback...
$500 test pipe from fabspeed (vs $550 SFR)
and $400 cat back from SFR (x-mas special)

--Adrial

Ok I get it, if you are going all the way to the Turbo then yes the intake must come off.

The test pipe and cat back is a easy change.

If you want to replace the turbo, then yes, you'll have to take off the turbo. It's a sod to get off the pipe without removing the turbo (can't get at at least on of the bolts)

It took me 1 1/2 days to get the turbo off and replace it!!! There are so many other bits you have to take off to get the room to access all of the bolts.

But hey, It should take out the restriction in the system nicely, and if your car's layed up over the winter months, then you'll have plenty of time to do it!

pikey, so your vote would be to replace the stock downpipe with SFR's 3" downpipe?

I would love to go for the SFR downpipe. Unfortunately I changed my turbo about a week before they released it, and so I now have no desire to take the thing off again.....

Read the blurb on SFR's website, and have a look at the pictures. As it says, there's not a lot of point in upgrading the rest of the pipe, when the restriction will still be there (the bottleneck effect).

Certainly when I go for my exhaust upgrade, I might have built up enough strength to have another go at getting the turbo out again!

I know that when I was asking on here about getting the turbo out, there wer a couple of opinions as to whether or not the downpipe needed to be removed, so I suppose the revers also applies here. My suggestion would be to take the thing out. Its tight in there!

I have recently ordered the entire SFR 3" exhaust from the turbo (downpipe) back as well as a new Stage 2 turbo. I am going with a testpipe and no Cat. I hope to have the order soon and will probably install it after New Years. I would be happy to post the results of my mod once they are installed. The car is an 86 Turbo with chips, otherwise stock engine. I need to go out and do some timed runs so I will have before and after numbers to compare.

Adrial,

RE: Easy of install??? It's actually VERY easy to install a test pipe and exhaust. The down pipe is all part of the test pipe and as someone else stated, it's only three bolts that hold in the downpipe.

A couple tips to make the job MUCH easier:

First- The key to getting the three bolts on and off the down pipe is to get *at least* a 12 inch extension for your socket. The longer the better. (This is probably the most important preperation to doing the job quickly and easily.) It should only take you about 45 mins for the entire removal and re-installation. After that, when the time comes to get your car smogged, you can likely do it in 20 to 30 mins.

Second, a little trick you may (or may not) know is to use preferrably, some masking tape (or electrical tape if you don't have the masking) on the socket to hold the nut and washers for the downpipe in place when putting things back together. Depending on the depth of your socket, you may want to put a little piece of wadded up tape inside the socket to keep the nut from falling inside, then take another piece and wrap it around the outside of the socket with only a JUST ENOUGH around the washer to hold it in place. Otherwise the tape could get stuch in between the washer and flange on the downpipe causing problems on the tightening.

Lastly: You will likely get some new gaskets with the new test pipe. (Ask when ordering to be sure you do, if not you could have a headache when you realize the ones on the car are either shot or wont fit properly.)

I made the mistake of thinking the OEM gaskets were better.... not so. (with the exception of the "doughnut" ring that goes around the wastegate bypass to test pipe. I would get a new one from the dealer before you attempt the install.)

As for the other gaskets, I got two flat "metalic pressed cardboard like" gaskets, one for the down pipe and the other for the cat-back to exhaust. Believe it or not, even though they look cheaper, the actually work much better than the OEM gaskets... I learned this the hard way and had to re-do the whole job with the gaskets that were suupplied with the test pipe.

Be sure to tighten EVERYTHING REAL TIGHT! then go back again in a week or so and retighten everything all over again.

Other than that, you should have no problems. Good luck and enjoy.

Use a good amount of anit-sieze!

Many people forget, and busting off a bolt is no fun!

It seems that there are some here that may not realise there are 3 seperate sections of pipe from the turbo to the exhaust tip...?

Or am I mis-reading the original question?