What is the best header/heater box setup to run with a 3.4l engine?

[89911]

I have used SSI's on my 3.4 for the past 3 years and I'm looking to go to headers. The last dyno had my car running 265hp and I was told be Steve Wong that my biggest restriction was most likely the exhaust. I really like how the SSI's are made and I am looking for a similar product that doesn't look like a cobbled mess from a high school shop project. I really do need heat for the spring and fall around here. Any recommendations?

[Steve@Rennsport]

There is no question that the 1.5" SSI's, while VERY well made, are just too small for best performance on a 3.4 litre engine. HP gets sacrificed for low-end torque with that setup.

We've had excellent success with a proprietary header/heat exchanger made for us that uses 1 5/8" tubing and retains factory header flange spacing to allow any OEM-type muffler to be used. Not cheap, but it works very well.

[Dennis Kalma]

Steve, we've had this conversation before, but I would really like to delve in to what would be necessary to build SSI's with one size larger pipes. I am at the front end of my build, it will be a street car and the torque/horsepower trade off is something that I am at peace with, but....

I have SSI's on my '75, they are beautiful, give me very good heat (essential here in the far north) and fit immaculately. When I dig around inside a bit, it seems like there is room to put 1/8 inch larger pipe sizes in there, albeit with a bit of a dent/change to the outside shroud....

In the case of your custom headers, are they in the same league as the SSI's in terms of quality, fit and finish? What would be necessary to get them there?

....and just a warning, I am actually anal retentive and proud of it....

Dennis

[Steve@Rennsport]

Originally Posted by Dennis Kalma

Steve, we've had this conversation before, but I would really like to delve in to what would be necessary to build SSI's with one size larger pipes. I am at the front end of my build, it will be a street car and the torque/horsepower trade off is something that I am at peace with, but....

I have SSI's on my '75, they are beautiful, give me very good heat (essential here in the far north) and fit immaculately. When I dig around inside a bit, it seems like there is room to put 1/8 inch larger pipe sizes in there, albeit with a bit of a dent/change to the outside shroud....

In the case of your custom headers, are they in the same league as the SSI's in terms of quality, fit and finish? What would be necessary to get them there?

....and just a warning, I am actually anal retentive and proud of it....

Dennis

Dennis:

As far as I'm concerned, there is not an exhaust on the aftermarket that is as well made as the SSI heat exchangers. IMHO, nothing else comes close.

That said, they do not make anything larger and John Daniel (the owner) told me many times that he has no plans to make larger ones due to the costs involved with tooling with that type of manufacture.

With that in mind, we have a 304 SS heat exchanger made for us with factory flange spacing to accept any OEM-type muffler. Its a good product that resolves the issue of engine performance on these 3.4-3.6 engines but its not as well done as the SSI's. I would tell you that these work very well and have been trouble free on a LOT of track cars, to date.

If the SSI's are your benchmark of QC for such things, I think you would be disappointed but there simply are no other such alternatives aside from headers, which of course do not offer heat/defrost capability. Some folks have used 993 HE's but that takes a good deal of fabrication and those primary tubes are rather short.

If you need further information, please e-mail me directly.

[89911]

Thanks Steve. The good part about SSI's is they retain there resale to help offset the cost.

[Dennis Kalma]

How much horsepower does a set of SSI's give away? I know there is no absolute answer, but in my case I am looking more for a solid, high performance touring sort of car, strong midrange and good high end (don't want to be embarrassed by any ricers or similar) but don't care if I give away 10 hp peak....

Dennis

[dzls rok]

how about ghl? i've heard alot of good things about them for vw/audi's, but not sure about them for porsche.

[Steve@Rennsport]

Originally Posted by Dennis Kalma

How much horsepower does a set of SSI's give away? I know there is no absolute answer, but in my case I am looking more for a solid, high performance touring sort of car, strong midrange and good high end (don't want to be embarrassed by any ricers or similar) but don't care if I give away 10 hp peak....

Dennis

The amount of power that is lost by using small primary exhausts such as SSI's depends on many factors: displacement, camshafts profiles, RPM range, compression, etc.

Undersized components will enhance low & mid-range torque and the crossover between small and correctly sized piping varies with engine size and RPM range. I would need all the details about your engine to tell you anything useful.

[89911]

Originally Posted by Steve@Rennsport

The amount of power that is lost by using small primary exhausts such as SSI's depends on many factors: displacement, camshafts profiles, RPM range, compression, etc.

Undersized components will enhance low & mid-range torque and the crossover between small and correctly sized piping varies with engine size and RPM range. I would need all the details about your engine to tell you anything useful.

I'll give you my car as an example Steve. I have a Motronic system with a Steve W chip and raised redline, Extrudehoned intakes, Bored throttle body, polished intake and exhaust ports, 20/21 cam, 3.4 Mahle high compression P/C's, twin plugged using a 964 distributer and Andial signal splitter, and other various hardware and improved valve springs. All this being dumped into SSI's. I thing maybe I've reached my own answer! What do you think headers would provide?

[mhunter]

I have 1971 911T 2.2 stock with an ansa exhaust. I never use my heater in my car since it always has that funny exhaust smell or is it rust. So I was thinking of putting some headers on. Do you think headers would give me more HP than SSI's?

thanks

[Jeff Alton]

I had SSI's on my 964 cammed 3.2. I sold them and went with 1 5/8 B&B headers with heat for my 3.4. I like the design of the B&B and the collectors but getting a suitable muffler has been an issue. I tossed the heavy droning B&B muffler and went with a custom M&K which is brutaly loud. It will be going and I will either fab up a flowmaster or dynomax to replace it.

I would use George's headers if I did not need heat to defrost the windscreen.

For reference the motor is a 3.4 with 10.5 CR, Mod S cams, twin plug, ITB's etc.....

After talking with Steve and John (camgrinder) about my build, 1 5/8's seemed to be the size to go with, but B&B may not have been the best choice.....

Cheers

[RWebb]

Originally Posted by mhunter

I have 1971 911T 2.2 stock with an ansa exhaust. I never use my heater in my car since it always has that funny exhaust smell or is it rust. So I was thinking of putting some headers on. Do you think headers would give me more HP than SSI's?

thanks

- No - the SSIs _ARE_ headers - they just have heater boxes wrapped around them. Headers would save you a bit of wt. in the rear if you never ever need heat.

You should throw the ansa at a passing Fcar (maybe Wayne's old 308) and get a real muffler. That might solve the odor issue. If it doesn't, then check out your stock exchanger tubes -- you may have an exhaust leak and they can be very dangerous - CO gives no warning at all before you die.

[mb911]

Originally Posted by Jeff Alton

I had SSI's on my 964 cammed 3.2. I sold them and went with 1 5/8 B&B headers with heat for my 3.4. I like the design of the B&B and the collectors but getting a suitable muffler has been an issue. I tossed the heavy droning B&B muffler and went with a custom M&K which is brutaly loud. It will be going and I will either fab up a flowmaster or dynomax to replace it.

I would use George's headers if I did not need heat to defrost the windscreen.

For reference the motor is a 3.4 with 10.5 CR, Mod S cams, twin plug, ITB's etc.....

After talking with Steve and John (camgrinder) about my build, 1 5/8's seemed to be the size to go with, but B&B may not have been the best choice.....

Cheers

Again wish that proto type muffler did not exist. must be one of the worst products ever