Group Buy: 3x8 Throttle Body Mod + Plenum Mod

We're talking about $2000 and 30 hp, so a 13% hp increase, thats 255 $/%. a pretty good return so I think it's on track with the point of where the thread is going...although that may be out the top of the budget

So, back to the question, do you know if the carbs themselves fit under the stock hood (no stack, no air cleaner) and if so by how much?

Are you manifold as short as they can possibly be?

I know it's probably best to have a couple more inches of room, but if the install is possible, I'm guessing there are a few people who would be interested in losing the CIS in favor of carbs if the price is right.

...which just made me think, a holley carb is about $250, I'm not sure how hard it would be to make the manifold for it though....I'd guess at least $1000, maybe $1500 so it might not be a much cheaper in the end. But it would fit, add 20-30hp, and you can get it from Jegs

 

Thanks Mark.

So for $52 you could gain about 5HP (Again your estimates)
OR
For $600 you could gain about 4HP (Again your estimate) and you don't have to risk a possible problem.

GEE I don't know which one to choose

Paul

 

Paul,

I love your hood. Do you have any other pictures of it you're willing to post?

 

Or a TBI system from a domestic, like a C4 vette or Fbody. I thought about it, but with that much fabrication there's better looking ways, not to mention runner design nightmares.

 

With re-jetting a carb or the CIS system you risk damaging the cat(s) or setting your car on fire if the cat(s) aren't happy about the extra fuel. If the cat(s) been removed, then the only down-side is fuel milage will drop about 10%. But it is 5 hp and certainly worht considering

 

Would not the O2 sensor set back the fuel distributor if the the mixture was increased in the K jet system?

 

I don't think it would be too hard to do a decent looking set-up.

Holley also makes a programable TBI setup that could be put on, but it's $825 instead of $250 for a carb.

Another option that would probably work is to buy the TBI set-up and puit it on the stock manifold in place of the stock TB. Now you have EFI for $825 plus about $100-$200 to make the adapter plate. That's about 94 $/% and one of the best options to date I think.

http://store.summitracing.com/partdetail.asp?autofilter=1&part=HLY%2D502%

 

I guess it would sure try, but that can be adjusted too. Some later systems CIS sytems use a throttle switch to disable the electronic O2 stuff under acceleration and rich trhe mixture…the link Paul posted says 85 or 86 I think. That stuff could be added I guess.

 

This MOD is only for non O2 sensor equipped Kjet systems (Ferrari 308 1980 thru 1983) which is what Steve has.

Edit: Just realized Steve's car is a 85 so Houston we have a problem.

 

Anyone that is looking for performance gains and is still running cats need look no further for a simple solution to gain some HP: RIP THOSE THINGS OFF!

Steve is running no cats so this is a no brainer for him and CHEAP $52.00

 

Steve,

Small problem: the mod is for non 02 equipped CIS (80 to 83 Ferrari's) and you have an 85 CIS system with 02 sensor. I am not sure how to make an end run around the sensor which will try and correct what change you make.

Sorry about this as I thought yours was an 83.

Paul

Thanks for comment on Deck Lid

 

Is the intake manifold/plenum appropriate for a wet flow? I'd be concerned that the fuel will drop out before it got to the intake port if you mounted it where the existing thottlebody is located.

 

You know, these figures being tossed around, I really dont understand why it would cost 3 to 6 times as much as a Jap car to bore out that throttle body. My son can find them all day long for his Mazda for under a 100 bucks. And they are ALL one offs, made from the body you send them. One site explained how to DIY. Its not rocket science. The hardest part is getting the throttle plate symetrical and to fit tight in the bore so the car idles right.

I dont think a TBI attached to the plenum is a good idea, seems kind of crude, and I would expect poor mixture equality between cylinders.

I don't understand why camshafts and valve timing isnt being discussed here in deeper detail. It seems that bumping the intake cam advanced to open at more like 25 degrees, and retarding the exhaust to open a bit later would make a difference. How much I wouldnt know, but using the Mazda as an example, its stock valve timing was about the same, and we bumped the cams around and it ran a lot different. Much harder pull in the low end. That 16 degree opening on the intake is purely for emissions, nothing else. I know reversion problems have been discussed, but I would be curious to see what happens when its pushed to the edge of that area.

 

I think you can get the same effect on the electronic CIS by simply adjusting the lambda. It’s fastest on the dyno with an A/F meter, but a nice hill and a looking for light tan plugs will get you to the same place.

 

Don't let Frank Parker read this. Cat removal gives him fits beyond belief.

 

If that gives him a fit
Send him a photo of my car and he will have a stroke

 

I think it would be ok. The manifold isn’t ideal for that, but honestly engines run just fine with up-draft carbs, this is way better than that. The real problem is wasting fuel, particularly when the engine is cold, and slightly uneven mixture, and both of those are only emissions problems really.

Along these lines, I guess you could throw a nice side-draft Weber on it too.

Or do a nice cross-ram set-up with 4 side-draft webers or even mikunis, that would fit under the hood, not cost too much (particularly if you get use motorcycle carbs), and look pretty cool…at least I think so.

You can get down draft mukunis too from late 80s, early 90s fzr1000 that would work great and cost about $200 for 8, plus $500-$1000 to make the intake. Pretty simple, relatively cheap, very streetable, and 20-30 hp gain – about 141 $/%

 

It's in the manual, it's like 2 degrees different on the exhaust if I recall. I re-timed my cams to match the euro spec, and it did widen the torque curve slightly, no increase in any number, just a bit wider power.

 

The biggest timing difference comes in the Marellei boxes as the US Version had retarded the ignition at idle so as to burn off as much fuel as they could in the exhaust ports.
Emission testing back then was done at idle.

If you own a US spec car and water temp climbs at idle just rev it above 1400 rpm's and the ignition retard drops out and the car will cool down.

 

Yes, the US ignition timing is just bizarre. I progammed the Euro maps into my ECU.

 

Here's one for $200 that might even bolt-on by the look of it.
http://store.summitracing.com/partdetail.asp?autofilter=1&part=BBK%

or if you prefer 75mm, same $200
http://store.summitracing.com/partdetail.asp?autofilter=1&part=BBK%

 

I click on your links and get Wheels, has the thread changed again?

Try this:
www.summitracing.com

Then use this part # EDL-3811 (70mm) $289 or EDL-3812 (75mm) $291
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sorry, Stupid summit makes it really hard to link to there stuff.

To to:
http://summitracing.com/

the part numbers are BBK-1700, and BBK-1701
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