GHL headers on a 930 and overboost?

[mark '87 930]

I am planning on installing GHL headers on my car tomorrow, and have read that the headers can cause overboost, is this true?

I intend on putting in the time to install them (I was guessing at 4-5 hours total), but don't want to fry my engine the minute I hit the throttle (melted pistons due to overboost is what I have read).

Thoughts?

[89turbocabmike]

Mark, this is generally a problem only with certain turbos, most commonly with the High Flow Hybrids from Imagine Auto/Ultimate. This is because they flow so much volume so quickly(which is good!) This can be cured by specing a larger wastegate pipe of the collector. If you are running a stock 3LDZ, K27-7200(stock C2 unit) or 7006 etc, this really shouldn't be an issue. It is always a good idea to go easy on the boost on your first run with the new headers just to make sure everything is working properly ie wastegate/overboost switch. What turbo and muffler are you running?

[mark '87 930]

Stock turbo (I haven't checked but I would assume the 3LDZ came with the 87's) and B&B exhaust from the turbo onwards.

I put a boost gauge on the car a few weeks ago (only for an hour or so) as a test to see what I was boosting too with the stock car and aftermarket muffler. All was good at slightly over 11lbs of boost. I will most likely put it back on once I get the headers on.

I take it from your comments I should do it and make the already existing grin on my face bigger!

[89turbocabmike]

You'll be just fine with that turbo and headers. Not to open a can of worms, but be careful removing your old heat exchangers. That is the trickiest part of the header install. Soak the exhaust nuts/studs with penetrating oil for as long as possible. You might want to do a search here and on the turbo board on rennlist just so you know what you may be up against. Headers are one of the best upgrades on a 930.

[slow&rusty]

Originally posted by 89turbocabmike
Headers are one of the best upgrades on a 930.

Well said Mike!!! I concur 101%

[mark '87 930]

Thanks guys, I started this morning (late) and am taking my time. I got 8 of the 12 nuts so far, and stopped for lunch (by lunch I mean beer). 2 of the nuts came with the stud altogether, which isn't bad as i can go out and look for the same studs, just new ones!

Thank Mike for your help and vote of confidence, it's actually going quite well. The car is surprisingly clean, so bolts are responding well to heat and liquid wrench.

[jrl]

With a goal of lowering spool-up about 500 rpm and funding to make only one change, which would be more effective, headers or K27-7200? Is it a close call? Also, is the K27 plug 'n play with the 3LDZ?

[magic930]

Depends what year your current headers are, the stock header with the J pipe flow quite well and an aftermarket muffler to remove the turbo choking catalytic convertor may be a better bet than replacing headers.

[jrl]

Right now, the car's completely stock, including converter and muffler. Pretty much, I'd hope for the easiest and cheapest way to get a few hundred rpm faster spool-up to make the car more enjoyable to drive around town.

[lukeh]

"I'd hope for the easiest and cheapest..."

Sad to say but no such thing with these cars. Especially when it come to cheapest.

[mark '87 930]

I ended up breaking one exhaust stud, so I'll have to fix that... but I have bigger problems. The oil line for the turbo tank isn't coming off, is there any special trick? I can't get the fourth exhaust (to the turbo) nut and bolt off, and if I remove the oil tank, which I have to replace anyhow, it will go much easier.

The wastegate muffler seems to be in the way as well, so I'm not sure if I remove this, it will make the oil like to the tank more accessible, but I don't know how much! I can't get it off and all of the bolts are off, so I don't know what gives. I was thinking of getting backto it in the morning since I'm done for the day

Help???

[mark '87 930]

anyone have trouble installing a header system?

Wastegate removal issues?
Drip tank oil line removal issues?

[slow&rusty]

Mark - I have been down this road so lets see if I can help you. The tank you are referring to under the turbo is the Oil Accumulator Tank this is tricky I had to fight with it...did you loosen the tank from the turbo already?

The wastegate can be removed as one piece with muffler attached, simple four bolts


[img]
then:



The corner bolt on the Turbo has to be cut off...I used a cutting wheel on a Dremel.


Hope that helps.

Yasin

[mark '87 930]

Yasin,

Your last picture shows the last remaining bolt I need to remove for the turbo, but I can't get to it with the accumulator tank in the way. I can't even get the turbo bracket off because the exhasut studs remain in the turbo. If by loosening it from the turbo, you mean that pipe clap looking thing, yes, I did loosen that.

The wastegate is unbolted (all four), but it is somehow seized in place! So I'm going to use a little persuasion...

[hobieboy]

Mark, wasn't sure if you have done this but remove the entire system as a unit, put it on a bench first. Give you waaaayyyy easier access to everything.
I ended up having to grind off one of the bolts when I did it a few years back.

[dyerkes]

Hi Mark,

I got your email, but thought I would post my reply here. The bolts on the bottomside of the turbo can be a bear to get too, and a bigger bear to get off. I'd suggest leaving the turbo bolted to the headers, just focus on removing the remaining bolts on your headers. Use plenty of penetrating oil (I use PB Blaster), and let it sit for at least 24 hours. Before attempting to loosen the nuts, pull out your torch and heat the nuts until they are red hot. If your nuts get rounded edges, I found that the nut extractor that Sears sells does a great job of gripping the nut (provided you have the space). Once you have the headers removed you'll have a little bit more room to get to the hidden bolt. With regards to your broken head studs...you'll need to get a tool such as the one referenced in this link in order to accurrately drill the broken stud out. Does anyone sell a fixture for drilling broken exhaust studs . Look for a response from Christian (A quiet boom is his logon ID ) in this thread. He makes the tool and can be reached by mail at rsr911@neo.rr.com . I've never used one of these, but I'm sure there are many others on this website who have. Are you still having an issue with removing the oil accummulator?

Good luck,
David

[mark '87 930]

Thanks for all your help, I'm planning on taking the day off tomorrow to attack this and get parts as needed.

I'll take the header off with the turbo on it and work on it from threre. I have to get that oil accumulator off first though, and that's when I quite last night.. It just wasn't budging. Which of the nuts for this line moves? The one that goies into the engine, or the one that goes into the accumulator tank? From the diagrams, best I can tell is that the oil line going to the engine is the larger nut which moves..?

[slow&rusty]

Matk - I just cannot remember my accumulator giving me that much trouble, I did this last summer. It was tricky but it came loose after a little fangling.

Nothing wrong with pulling the turbo still attached to the manifolds either - just extra weight.

Tap the WG with a hammer to get it free-up...corrosion probably has it welded to the flange.

With the GHLs in plave everything is SO much cleaner and easier to get to than the factory pieces.

Yasin

[mark '87 930]

As an update... I got the accumulator off, the nut on the tube going into the accumulator does nto move, so the other is the one to loosen. I took it off and proceeded to disconnect the heating tubes.. The wastegate is being stubburn, so they are coming off with the headers! So is the turbo for that matter.

Now the headers are hanging there and the bind is the turbo pipe that goes into the intercooler. I am going to hit it again tomorrow morning as I took the day off. I want to get this done...

Any tricks for the turbo?

[89turbocabmike]

The pipe between the turbo and intercooler just slides onto those two items and is sealed with captured o-rings. They maybe stuck alittle from being together for so long, but you should be able to work it off. You may want to remove the intercooler and that will give you extra leverage and movement to get the "up pipe loose from the turbo. I assume you've already disconnected the oil line that connects to the top of the turbo? That is more likely to cause a hang up.