Civic VX: Headers vs stock exhaust

[Joe1234]

Originally Posted by Ryland

I'm on my 2nd Civic VX and have owned a hand full of other super fuel efficient Honda's..

The only Honda that is supposed to to get better fuel economy than the VX (according to the EPA) is the insight and some special version of the ever-so-ugly CRX. The insight costs way too much to be worth it and the CRX is just too damn ugly. that leaves the VX as the best option IMO. Is there another, more fuel efficient Honda that I'm forgetting?

[CigaR007]

Originally Posted by Joe1234

I just bought another VX instead. Now I just need to put the clear coat on the old one, put thicker oil in the tranny, and sell it for what I paid for it.

Best of luck on both fronts then !

[mcrews]

Originally Posted by Bow

Wow, nice personal attack...

Obviously, you know everything about the Honda Civic VX...

You probably also know that the first choice for home-brewing Honda Civic Turbo systems on the cheap is to get a VX Exhaust manifold.

I'm sure that is do to its highly restrictive flow properties.

If you want to read something, I'm sure the Honda guys know a thing or 2 about Hondas.

How To Turbo: LOOK HERE FIRST - HondaClub.com - Online forum for Honda and Acura owners

If you are lucky and/or good, some stock header sections can be made to mate with a turbo (the D16 manifold from the Civic VX is one such manifold). The key thing here is if you are cheap and buy a pre-built manifold, buy one that is made of cast iron. Tubular manifolds look cool and offer more power, but are prone to failure. The tubular manifolds that are not failure prone are very expensive (they are worth the price of admission. On some engines a properly designed and built tubular manifold can be wroth 30 hp!). Iron is heavy and ugly but does not break and is also quite cheap.

But I digress, you obviously know everything there is about I4 engines and designs, you drive a 340hp/333 ft/lb 4.5L V8, 3800 lb, fuel sipping ecno car.

yeah, hommie Yeah, I got a nice bonestock V8 that will light up your world like the 4th of july with the VDC switched turned off. And yeah all my mph runs are with the A/C set at 72 degree. And it has 245,000 miles

this isn't a 'size' contest so keep your shorts on.

But the forum is 'wrench smart, drive smarter'. Not drive an eco box because I feel guilty.
******************************************
well at least I'm consistant!!!!!
First you tell us that there is no difference. (stupid)
AND if you had just read the whole thread you would havebeen at least smart enough to NOT say theres no difference.
THEN, you come back with you (watch me google this and show him) post that infact the header IS different because the turbo boys wantit so desperately.
THEN you make up the reason why!!!!!!!!!!

THank gosh ryland is here to keep you a little bit accountable for the rash of bs you have dumped on this thread.

So yeah...take it personal.....by all means.



and finally, you can tell alot about a poster if you look at the ratio of posts to thank yous in the avitar section....
just sayin.

[mcrews]

Originally Posted by Joe1234

The only Honda that is supposed to to get better fuel economy than the VX (according to the EPA) is the insight and some special version of the ever-so-ugly CRX. The insight costs way too much to be worth it and the CRX is just too damn ugly. that leaves the VX as the best option IMO. Is there another, more fuel efficient Honda that I'm forgetting?

I always had a soft spot for the first gen CRX.....they handled like a slot car and had power to wieght ratio like a ferrari

[re-evaluating]

Originally Posted by Joe1234

The only Honda that is supposed to to get better fuel economy than the VX (according to the EPA) is the insight and some special version of the ever-so-ugly CRX. The insight costs way too much to be worth it and the CRX is just too damn ugly. that leaves the VX as the best option IMO. Is there another, more fuel efficient Honda that I'm forgetting?

I realize the OP has bought another car and this information no longer matters to them but since I am dealing with this exact situation I thought I would add some thoughts to an already good thread.

First of all I am building one of those ever-so-ugly CRX's as we speak. Ok it isn't the best looking car in the world but I think I have driven worse and if I can get 50-60-70 mpg I can live with it. LOL.

I used to work at Summit Racing for several year some time ago so I have a little bit of training or insight to what works and what doesn't work and why in the performance arena. I currently own a mid 9 second 140 mph (1/4 mile) V6 Buick. I certainly don't claim to know everything but have learned a few things in the 35 years I have been playing with cars.

My car is a 90 CRX Si that I am have an HF drive train in and one big concern I have is the exhaust. My car too was mutilated in all directions by some 16 year old. I have 3 of the HF or VX manifolds on hand but don't have a good converter which would improve heating of the 02 sensor and other factors as engineered.

Currently on the car is a set of these junk 4-2-1 headers with the O2 in one cylinder pipe. I don't have the exact diameter of the tubes but something larger than 1 inch and a primary length of about 10 inches. This header is much better suited to a 7000 rpm 200 HP engine than my 62 HP @ 3000 rpm engine HF engine.

They will make more overall HP gain at 7000 RPM up than stock manifold but that comes at the expense of a lot of torque at lower RPM which is what you need with the final drive in HF 2.95 or VX 3.25. I think there are gains to be made over the stock manifold with a small diameter, long primary tube header, but the stock would be a much better choice than these ebay crap.

I believe the large tube header will hurt fuel mileage because of the reduction in torque and will require a heavier foot to get up to and maintain speed at 2000 rpm. The only possible benefit I could see is if the wider throttle position reducing vacuum drag could possibly offset this but I find that highly unlikely but open minded.
I plan on removing the header from mine once I get some of the other bugs worked out of my build. Once I get the car running to my satisfaction I plan to build a set of small tube headers to replace them unless I decide to turbocharge it.

Just my thoughts on the subject.
Dave

[mcrews]

wow.... take notes......a comprehensive, well thought out and relevant post on the topic.

no guessing. no 4cylinder truck engine stories, no different versions......validates his background.......

how refreshing.

[mcrews]

dave, met joe and ryland!!!!

you boys can start a little club!!!

[Bow]

Originally Posted by mcrews

and finally, you can tell alot about a poster if you look at the ratio of posts to thank yous in the avitar section....
just sayin.

Yup, you sure can.....


You are right, I know nothing....

I'll go back to saving gas with my truck, and reducing my carbon footprint with my E85 converted 240sx....

Have a nice day

[Ryland]

Originally Posted by Joe1234

Is there another, more fuel efficient Honda that I'm forgetting?

I've also owned a first gen 1985 CRX HF, it had a lot of interesting bits about it to help squeeze that extra few MPG out, like an aluminum air cleaner housing to keep the weight down, 12lb steel wheels, a single piece exhaust from the oil pan to the tip of the muffler (over 9 feet long!) and in 1986 that same car would have had aluminum rear brake drums.

I also owned a 1983 Civic DX hatch back that I installed a Civic FE hatch back transmission in, I only owned it for a year and still had a lot of work to do getting it running better but was getting mileage in the mid 40's, the Civic FE was supposed to get mileage in the mid 50's with it's 1.3L engine and later body styles got in the upper 50's low 60's if I remember correctly.

Then yesterday I borrowed my parents Honda N600, no EPA numbers on that, but depending on how you drive it your mileage can range from 40mpg up to 70mpg, theirs needs a tune up and has a gas leak so it's getting mid to upper 40's right now.

An Insight is next on my list of cars to get, unless I just skip driving gas cars all together and find a good way to heat an electric car in the winter.

[Joe1234]

Originally Posted by Ryland

An Insight is next on my list of cars to get, unless I just skip driving gas cars all together and find a good way to heat an electric car in the winter.

insights are too expensive IMO. Here's what I mean by that (mathmatically): Take your old car/truck MPG, the cost of gas and your new car's MPG and you can figure out how far you have to drive your new, more FE car to for it to pay for itself. The formula can be graphed out like this:

f(x) = -( old cost per mile - new cost per mile ) x + price of new car

In my case: -($3.50/18MPG-$3.50/45MPG)x + $2,500

If you graph that and find the X intercept, or solve for X, you get about 21,552 miles. That's how many miles you'd have to drive the new FE car to make it pay for itself in fuel savings. The miles you'd have to drive would be super high for a more expensive car like the insight or if your previous car was already pretty good on gas.