Headers... practical experience?

[oredith]

OK, part II of a continuation from long ago...

My car (76' with a 73' 2.0L engine) is finally up to snuff in terms of street safe driving (all tuned up), now i'm looking for performance improvements. I've asked about WHERE to get headers before, but never about actual experiences with headers.. I got scared about putting on headers after reading an article in ..?? road&track ??.. about Integra headers.. most of them gave an improvement of 1-2 total horses.. and two even gave NEGATIVE power gain..
Please share with me some personal knowledge or experiences with headers, or even hypothesis on what adding headers would add or subtract.

Thanks in advance,

Jeff

ps. dave, if you're reading, i've read some of josh's postings on rennlist, just hoping to get some more opinions 8^)

[JP Noonan]

Well, experience wise, I've installed two differnt exhaust systems on my Lightning (351W Ford EEC-IV Speed Density FI) one "shorty" type and one "long tube". For me the smaller primary (1 5/8" I think) long tubes made more low end torque, which for my 4700lbs vehicle is a good thing. I think the shorties are more for the Mustang crowd. Then there is the equal length, and "nest of snakes" types. I dunno, I know scavenging of the cylinders helps but how much?

Here's what I say, without a ME degree, or a flow bench. A perfectly designed system is only good for a set RPM range. If you run a circle track (if you run a circle track in a 914, I will beat you) and run all day at a certian RPM then there is a perfect set of headers out there, but it will blow on the street. I think the SSI heat exchangers are a good bet with an extractor type muffler (like the Bursh) Bugs have for a long time gained power from an extractor type exhaust. If you get into four into one headers (again I'm not thermodynamics guru) and a supertrap you are looking to be at the high end of the RPM range, you will most certainly loose some low RPM torque and HP, but only gain a few at the top. In racing this is good, for street not so. If you are going to race see what the other 914's run in your class (and if they won't tell you, wear an official looking orange vest and start looking at their car, when the ask who you are just say you're a hunter that got lost ;-) )

BTW the 2.0L SSI tubes are the same diameter as the 1.7/1.8L SSI tubes. Sorry for the rambling, but you kinda asked a broad question. The SSI and Bursh made a big difference on my '75.

[djs]

I would have to agree with J. P.

I retrofitted a pair of 2.0L SS heat exchangers and a new Bursch "quiet" exhaust system onto my '75 California 2.0L (one of the more "power-starved" models based on required smog equipment of the time), thus doing away with the catalyst and the "reverse-exit" stock heat exhangers. Everthing else is stock except for electronic ignition and a K&N air filter.

The difference in tractability and performance is VERY apparent compared to the '75 as originally equipped. The peak power band seems to have moved from between 3-4000 to 4-5000 rpm. But, this doesn't mean that my car feels week off the line. Quite the contrary, if anything, it's now quicker off the line due to a general increase in power.

Also, the engine revs much quicker, owning to less back pressure (I assume) and in terms of "seat of the pants" feel, I would say that I am now making all of the rated 95hp of my engine. I can't speak for other people, but the conversion to SS exchangers and an extractor-type exhaust has done wonders for my car's "fun factor."

In my opinion, 95HP is adequate power in so small a car for most driving situations, except for highway acceleration, where I could use a little more "oomph". To address that, I plan to build a slightly more powerful 2.OL this winter with Euro pistons, balanced & blue printed engine and ported/polished heads.

To recap, if you are still running the '75 emmisions equipment and exhaust, retrofitting the earlier exhaust should make a noticeable difference. However, there is the issue of smog inspections to contend with, meaning that, to pass an undercar visual inspection, you will have to bolt the "correct" pieces back on every two years until 2003, when the '75 becomes exempt from such inspections.

[Joe Bob]

Yo, Jeff.

There is a difference in "headers" and "extractor" systems. Headers eliminate the heat exchangers (no heat!), while extractors bolt on to the heat exchangers and give a freer flow of exhaust gases.

Wait until you are exempt in 2005 before you do it. Then get the Kerry Hunter headers.

If you are just looking for an increase in power and different exhaust tone, the Bursch extracter system will help out a bit but not much.

Just my experience.

[This message has been edited by mikez (edited 09-11-1999).]

[JP Noonan]

Mike,

How loud are those Kerry Hunter headers. If they are anything like the megaphones I've heard on the track I can't see them being legal for the street. Also where is there power band?

I dunno, maybe this is more of a personal prefernce thing then I thought.

[Joe Bob]

The Kerry Hunter headers come with a tuneable Supertrapp muffler. They can be adjusted for back pressure/sound and are CA street legal.....but any cop with a DB meter or a bad mood can and will pop one on the justification that "he" is right and you need to prove him (the cop), wrong.

Ask me how I know...I've probably have had more tickets in my youth than I have had cars....and I have had over 35 cars....The Supertrapp works, just needs trial and error.

Regards

Michael
Air Cop

[DonNewton]

Mike's correct here about the noise police. However, if you've ever been on I-5 and been passed by an unmuffled (is there any other kind?) Harley, you have to wonder what the police are doing about these guys. I guess the PC police just aren't working when the hogs come out to play.

[oredith]

Thanks everyone for your input,

I think i'm going to order headers from Kerry Hunter (pending my next paycheck) and just swap the heat exchangers on in 2 years..

Noise problem?.. not a problem in LA.. i think the LA police have their hands full with car chases everyday, i doubt i'll ever get pulled over for the noise.. (you can go ahead and laugh now mike!)

I just wanted to make sure i won't be loosing power with headers like the integra guys..

Thanks again,

Jeff