Swagger93

I'd like to start this post by saying I am incredibly frustrated with the exhaust system on my car between the engine and the turbo. These parts have been nothing short of nightmarish for me, and it is starting to bother me to the point of selling my car. I want to avoid this. However, I was under the car today and found more cracking.

The issue is, like I posted on Carsurvey, that in addition to pricey parts that I'd expect to be replacing, the crossover and header network continue to crack, crack, and crack some more! First it was the wastegate inlet pipe (I have two piece, btw), which we welded and has so far held. Next, it was a leak that developed next to the engine on the number three cylinder, which I have ignored because it seals once the car has warmed up. Next, the crossover pipe cracked, and it was a delightful crack, and is on showcase below. We welded this as well, though only to keep my car on the road, I would ordinarily have just ditched this pipe. I began to drive and enjoy my car some more, when another crack developed at the bottom of the headers, on one of the flanges by the crossover. Then, finally, and this is what made me put the car away prematurely for the year, was the crack that developed on the crossover pipe where it meets the wastegate inlet pipe. WHEN WILL THIS END?!?!?!?!?!?!?!?!?!?!?!?!

I am ready to ditch all these pipes for either a good used stock set or something customized. I saw some neat stainless header/crossover combinations for sale online, but they are going for exorbitant prices running into the 1900 dollar range. I am a college student with a lot of resources, know-how, and ability to fab stuff barring anything that needs intensive welding, but this is driving me crazy.

In any case, I'm pulling the engine in the next few weeks. Will replacing the headers with good stock used ones be just spinning my wheels? It seems the biggest challenge is making headers that don't crack and that produce the torque of the stock ones. My friend just purchased a fairly complex header pipe for his miata new for 100 dollars. It's not great, but with a little more welding and machining it will be ready to go.

Anyone selling crossover, headers, or inlet pipes?

95Juan

do you have the bellowed type headers? i dont see anywhere in the post any mention of that, but that seems to help by about 200%.

Sam Lin

You need to inspect your exhaust, frame, and engine. Something is wrong with your car causing severe misalignment. I've not had a single crack on a car over 200k miles.

Sam

Ski

Broadfoot Racing and SFR I think are the only ones manufacturing and selling complete systems at the momemnt. Do NOT forget your checkbook or VISA card.

Swagger93

Could aging motor mounts be at fault? I have two new ones ready when the engine is to be reinstalled.

The post turbo exhaust looks great, the car is accident free.

The headers are the bellowed.

daniel951

Danno was actually going to help me come up with a design for headers but lately i haven't had time to start the process. I know i could give people pretty good deals on the products since my buddy owns a machine shop. The reason why i thought about doing this is because i can't see myself paying those kind of prices for headers when i see the f-body guys getting theirs for around 300-400 bucks

evil 944t

I think once you sit down and realize your material costs and the amount of time that goes into it, You will be surprised how much it costs to build headers.

There are alot more F-body guys than 944/951 cars out there.

I'm building a set to move the turbo to the passenger side on my track car, it's not cheap. When I'm done, I'm going to build a setup for my street car. It will be kind of similar to stock but in a way, very different.

samluke

Are you sure you don't have an engine vibration problem? If the balance shafts are not timed properly, you can experience a lot of vibration related problems. The bottom balance shaft can easily be set up 180 degrees off, and it will still look right. If you have a vibration problem then you will continue to have problems, untill its fixed

Swagger93

The balance shafts are definitely timed properly, I've mistimed them once on my '88 16 valve and because of that experience (mirrors falling off, the whole works) I'll never mis-time those again. I just did a re-tension and check the b-shaft marks, and it's all set. Besides, I'd have no teeth with how much time I spend in the 4k+ rpm range.

To tell you the truth, and knowing how unknowing the last (and original) owner was, the motor mounts may have never been replaced. Even though the car only has 85k, they would already be up for a second replacement at this age. Lots o' vibration at idle, but the engine isn't moving all over the place when revving like it has in my motor-mounts-are-completely-collapsed FWD cars (and wrecked the exhaust).

Crazy Eddie

I havent seen a crack like that EVER ! That is nuts. As others have stated there has to be a reason and I really don't think is just a ****ty design otherwise it would have happenend to others. They, the headers, from time to time crack, but is less than often.
Your car has low milidge and its a 88, so its really weird. I feel the same way, about the cost of these exhaust systems, as far as the high cost ... But I also think that a 400 dollar 10 inch down pipe is equally nuts !!!
There are a # of decent haeders offered from time to time but I would only buy a used set from someone you know & trust...
Good luck
Regards
Ed

brad-cam

I vote for engine mounts as well. When they slowly deteriorate, they collapse, putting enormous stresses on the exhaust system, primarily at the crossover-wastegate junction. This stress on the crossover pipe leads to all sorts of issues. I had motor mounts that had collapsed 1/2". It was very hard to tell other than measuring them against spec. My headers cracked all to hell. New mounts and a good set of used headers and I was good to go.

So... don't put any more money into the exhaust system until the motor mounts are replaced.

special tool

Swagger - what turbocharger, boost level and chips do you run on this 951?

Swagger93

Car is totally stock, K26/6.

It's an '86, not an '88- FYI.

95Juan

could having crazy monkeys standing on the engine and moving around make it a little bit misaligned? hahahahahhaa

Mike S

Is the turbo mounting bolt tight? The one that anchors the mounting plate to the back of the motor near the down pipe?