39 replies to this topic

[cbstdscott]

As rational and analytical as we would like to be, those of us who persue the automotive hobby are as susceptible to the influence to fashion as teenage girls on a shopping binge in Forever 21. If you are honest I know that all of us have added a modification to our favorite car because "it looks cool" or "all the otber guys are doing it." Lurking deep in my automotive past have been questionable automotive life decisions that I am not proud of. And no, I am not going to delve into spiritual confession right now. Not withou dinner and a moviecfirst.

Back on topic: Power adders have gone through phases of fashionability. In tbe early days of Hot Rods high compression heads, open pipes and better flowing carbs were effective and communally aaccepted as ethical means of making more vroom vroom. Mysterious and slightly suspicious was an aviation adpatation, fuel I njection, which never really became embraced by the larger Hot Rod commmunity. But because big shiny blowers sticking up through the hood looked so Boss, Super Chargers really caught on with the cool crowd.

During the gas crisis of the Malaise Era, turbos were found to work well with small displacement engines and slapping a turbo oneverything from Pintos to B bodies became the rage. As the Xers inherited Mom's clapped out Civic they leaned toward adding a swirling snail to D series. But go ing turbo requires a lot more work than just bolting up some plumbing. Turbos require some fairly sophisticated engine management to live longer than a couple of exciting Saturday nights.

So if you are willing to make the commitment to building a turbo engine from scratch, it is possible to get a ton of power out of a small engine using the miracle of exhaust gasses to compress incoming air.

Me, I am not so inclined. Turbos are great but I like my connecting rods inside the engine block. And all that complicated ECU/rewiring/sensor stuff to modernize the 1st gen's engine management to safely accommodate turbo charging is beyond my level of comfort.

[cbstdscott]

But I need "Moar Powah!!"

What are my alternatives? Back in the day Mugen turned to tried and true side draft carbs, combined with a bit more displacement, a trick cam and head work to spank out about 1.5 hp per cibic inch in a full race engine. Even a milder street engine can see impressive hp numbers with side drafts eliminating the very restrictive intake manifold and tiny stock throttle body.

A set of side drafts, a twin carb manifold, the correct linkage anf fuel lines are commercially available for a price. A big price. And carbs are a terrific pain in comparision to the simple efficiency of fuel injection.

I have bored out mt stock tb, I have changed to a bigger tb and they have incrementally raised power output measurably. But still I need more. And to get more I need to overcome that tiny, choking intake manifold.

[cbstdscott]

If our cars had more modern engines we could buy a brand new intake manifold from a couple different providers. Hell, you might even have a choice of natural or polished finish. Single throttle body or individual throttle bodies, it is possible to just bolt it up. We are not so lucky.

A digression: Why not dump this old lump and put in a B series? It would be so easy to do and performance parts are plentiful.

I have a soft spot in my heart (and apparently my head) for the stock EW engine. It is old and weird (just like me) but is not a bad design. In fact the DNA of every subsequent Honda I4 engine has traces of th e EW in it. While it never had a reputation for huge power it is rugged, dependable and relatively light. Adding a B series will also put more weight over the nose of this little car. A you can count on being just about the only guy at thd track or meet going all old school.

Plus, I am very lucky to have a Mugen LSD in the EW specific tranny. So you know I am not going to give that up.

[cbstdscott]

Any way, I ned more power. To get it I want to stay Naturally Aspirated and I want to keep fuel injection. So I need a better intake manifold and thet are not commercially available. So that means I have to make my own.

A search of "make your own intake manifold" turns up lots of pages that show you how to do it. You can buy all the parts to make your own single tb intake and many sites explain how to determine runner length to tune gor max performance at a psrticular rpm. But our little cars have space restrictions under the hood and the optimum I take/runner/plenum design will be a tight fit.

And... now the fashion part comes in... just fabbing up another single tb intake just does not have the Wow! factor I am looking for. "Ho hum, common as dirt, he probably bought it on eBay" is what the great body of the clueless will say even if I design and build the Ultimate Single TB Manifold. If I am going to all this trouble I want to go Big Time. And Big Time demands a set of Velocity Stacks feeding four throttle bodies.

Remember when I said I was not going to make any confessions? Well I have a confession to make. I got my one of my first automotive woodies way back in the mid 1960's when I laid eyes upon the eight velocity stacks crowning the small block Ford Indy engine. That was so bitchin'. Tottaly unlike all the dinosaur engines roaming tbe earth back before the dawn of time.

So now you know why I want to create my own ITB setup on my CRX.

[cbstdscott]

Making your own ITB set up is not too hard... if you know what you are doing. That eliminates me. But it also will not stop me from blundering forward.

Essentially all you need is a set of motorcycle ITBs which you can get cheaply off eBay, some aluminum tubing and an old stock manifold. The junkyard yielded a manifold for my project, I scored a complete set of ITBs from a Honda CBR including the air cleaner assembly and the sleeves that attach the ITBs to the motorcycle engine for less than $100. The aluminum tubing is easy to source off the internet.

OK, there are a few small tricky bits. One of the first is to devise a way of interfacing the ITBs with a TPS that will work with the stock ECU. I was lucky enough to have a stock TPS on hand and so I have McGyver'ed a mechanical interface. Later we will delve into the vacuum lines you will need to feed from the ITBs.

So I will wrap up this portion of the Project Thread until I have some pictures to show you of my progress. next time I will show you how I am hacking. er... surgically removing bits and pieces from the stock manifold so that it sill be ready welding on the aluminum tubing.

Final thought for today: If anyone has the skills and knowledge to do this a better way please share them with me. I do not claim to have a monopoly on how to do this job. Far from that. I am blinding making some guesses, educated and otherwise.

Scott

[Hollowman]

Hey there Scott.  It has been a while since i have posted here at RPR but your project got me thinking.  I did a dual Mikuni carb set up on an 84 Corolla Coupe (AE86) with the 16vlv 1.6L that I got from AEM before they went corporate and I remember how they did the vaccum lines.  They had me tap into each runner to get the vaccum I needed for it.  They told me that I needed it this way or I wouldn't get constant vaccum for stuff like the brakes. If I remember correctly it was 4 1/8" fittings connected by tee's that stepped up to the 3/8" for the vaccum line for the brakes. That would provide the vaccum issue and you probably could use that for the vaccum advance for the distributor but if my memory also serves me right you have a re-curved dizzy.

 

You will also have to address the MAP issue as well. That is a whole other issue that I don't have an answer for. Sorry.

 

Here is an issue you will have in my opinion, fuel mixture.  Going to the individual TB set-up fuel requirements will be way different than the single TB set-up due to the increase of air entering the runners (more air + more fuel = POWAH).  You will have to address this to get them to run correctly to produce good power.  You could do this several ways: stand-alone ECU (expensive), OBD1 Civic ingition upgrade (I believe Marcus had this on his silver CRX) and ECU with a piggy back system, or just the piggy back system to control the fuel.  Cheapest way would be just getting something like the Apexi AFC and get it to work but the spark advance may fall short even with your re-curved dizzy so you won't get the maximum gains but should do a decent job with a good tune.  You are still using the good old mechanical B&M type fuel pressure regulator correct? That would give it the adjustable pressure you would need I would think.

 

But take this with a grain of salt.  I don't know everything either and by just working my brain a bit I came up with what I thought you may need to think about IMHO. I think I keep checking on your progress to see how this works out. I miss these projects. Once I get some time again. Haha

 

Shawn

[anjin]

Hi Scott
When I bought my Red g1 there was a set of motorbike carbs in the back - mikumi for a Yamaha R1000. Not Fi, but a good find. That has linked vac connections to feed into one line. I think it would be worth looking at a bike set-up for ideas on that.

And I agree with Shawn on the air fuel mixture problem. On the carbs I will need to go to jets of 18 or 20 size for the B18 if I went that way, or stay about as they are for an EW. You will need to know the itb fuel injector characteristics so you have some idea of your starting air fuel ratios.

I think you could just go for the apexi VAFC to piggyback the EW ecu and control your fuel maps that way. I've done that with success when using big cams. It worked well, reliably, and was a cheap option. Or you could play with fuel pressure and injector size.

Have fun with it. Nothing like a tinker in a new area to keep the brain active.

[cbstdscott]

Thanks for the replies. You guys touch on to issues I have been thinking about.

The ITBs I am using have a pair of vacuum "manifolds" (rubber tubing) that I can use for my vacuum needs.

The fuel mixture is an interesting challenge. The one thing I have learned is that it is easy to over estimate how much extra fuel a modification will require. I do have an adjustable fuel pressure regulator (made.by TurboRex) and a set of Integra injectors if I need them. I will start with stock fuel pressure and injectors, see what kind od readings I get from my narrow band O2 sensor and work from there.

In an ideal world I would move to a more sophisticated management system. And I may be compelled to do so. But to begin I want to see what I can do with tbe existing system.

Just an update on the progress: I am in the process of trimming the unnecessary bits of the stock manifold and I have ordered the aluminum tubing.

Scott

[cbstdscott]

Pictures

https://www.facebook...&type=1

[Hollowman]

Hey Scott. Here is a link to an RPR FS post for an EW side draft manifold.  I think this may be a good reference for your ITB project.  The setup is simple and probably be something you can emulate for your intake.

 

http://www.redpepper...showtopic=54807

 

And I came across this:

 

http://www.redpepper...torcycle carbs

 

Your original post regarding the CBR600 set-up got a bunch of responses and I read it all. So you finally are going through with it huh? I'm rooting for you!

 

Shawn

[zakats]

Leave it to Scott to make his project thread into a magazine article

It's an entertaining read thus far and I'll be following your progress, keep up the good work!

[cbstdscott]

Shawn,
.
Thanks for pulling up my old post. After years of fermentation I am crawling forward with this project.

[cbstdscott]

Zak,

Imagine that famous picture of Fry and me saying, "Not certain I know what I am doing, but proceeding any way."

At this point I have finished the easy part, assembling the parts. Once my tubing arrives I can move on to fabrication. I have no welding skills and I will have to find a welder who wants to be part of my grand experiment. This is not like welding a couple of right angles. I will start by talking to my local welder who is a story unto himself.

Dennis the local welder is colorful. He works out of a tin shack behind a chilli stand in the heart of fashionable West Los Angeles. Just steps away from the offices of movie producer/directors and hipster restaurants is a scruffy old man in dirty overalls plying his trade like a wild west blacksmith. Functionally illiterate does not prevent Dennis from being eloquently
profane. A multi tasker, he can weld while slandering anyone and anything that displeases him.

And he is a car guy. If his claims are to believed, he worked as a lot man for Carrol Shelby in the 1960's. Even if only half of his stories about wrangling 427 Cobras and Mustangs are true he has qualified as a hero to me. After his days with Shelby, Dennis worked as a handy man on the 20th Century Fox movie lot where he has hilarious tales of the foibles of film makers.

If Dennis does not want the tricky job of making square pegs fit into round holes my fall back position is to enlist the help of a welding and fabrication shop in Venice, California.

[cbstdscott]

Venice, California is a seaside community on Los Angeles' golden beach. A curious mix of millionaires mansions and dangerous gang turf, it is the embodiment of urban dynamics. Build in the 1920's as retreat from tbe city it lost its luster in the 1930's when oil was discov ered under the sand and spiraled down into a haven for bikers and junkies by the 1960's.

When Malibu bcame too mainstream for the young elites of the 70's movie world Venice became the slumming glamour spot to write screanplays and pitch movie deals. Venice's indigenous community of what are charitably referred to a "economically disadvantaged" are still not too happy are the new urban pioneers. So if you want to slouch toward street cred while maintaining an upscale lifestyle be careful that your authenticity will not be challenged at the end of a gun barrel.

Venice one of the remnants of Venice's less fashionable past are a number of warehouse spaces that are now morphing into artist studios, pretentious dining facilities and boutique shops. In the heart of the commercial portion of Venice is a welding andcfabrication shop.

[cbstdscott]

The welding and fabrication shop is not personally known to me, I have not done business with them nor even visit their shop. I only know about them because I heard the shop owner interviewed on National Public Radio. He has repowered an early 70's BMW 3.0 coupe with a home built DC electric motor and a shit load of lap top batteries. Apparently it creates so much low end torque that it creates massive burn outs that require replacing the rear axle with a Ford 9" unit from an Econoline van.

My kind of guy.

So perhaps that shop will have the skills and patience to bridge the gap between the ITBs and the remnants. Of tge stoc k manifold.

But I worry that this shop may cater to the rat rod, flat hat and tats crowd who value style over functionality. Not that I am in a position to judge others but I am more impressed with clever and efficient design and execution than achieving a crowd sourced approval for conventional wisdom.

For now, my project is on hold for the weekend as I wait for the tubing to arrive. I will pick this narrative next week.