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View Full Version : Intake manifold? B20?



FyreDaug
10-03-2005, 09:16 AM
Ive got a a20a1 with full exhaust, custom short ram, dual ignition coil, vacuum removal and high gap plugs with more than the max stock advancement.

Considering an intake manifold, dont really feel like porting stuff, I kind of lack a dremel aswell.

What does it take to mod the b20 manifold on there? And does it still work good with a carb? I'm not going through all the work of converting to FI, just minor bolt ons here and there until the car blows itself up. So I'm not too worried about things done the proper way.


Actually, you know what... I'm gonna go take a picture of my engine bay right now, and you can give me suggestions keeping it on the ghetto side (as the rest of the car is). Sweet. (will edit)

A20A1
10-03-2005, 01:31 PM
JDM B20?

That is EFI, EFI manifolds don't work with carbs cause they aren't built to flow fuel, you'll get fuel hung up in the runners.

FyreDaug
10-03-2005, 01:58 PM
Besides custom what else we got? Anything that'll fit? Or should I just port the crap outta it (worth it against a custom one?)

All pics located: http://www.3geez.com/showthread.php?goto=newpost&t=46802 (site was down before)

A20A1
10-03-2005, 07:15 PM
Well for a down draft you can make a custom one or port the stock manifold.

I can sell you mine down the road some time.

rjudgey
10-04-2005, 08:39 AM
Nothing that you will do will change it that much unless you know about physics and airflow. I would just get a weber carb adapter and find a secondhand weber from somewhere either a 32/36 or better would be 38/38 DGAS.
If you had someone who can weld ally then get a new inlet manifold madeup and then as CKE suggested use Bike carbs.
I'm eventually going down that route but with racing bike carbs as their even bigger!! At the moment still using Webers and maybe even ITB's with the B20A as i've got a friend with a spare Omex aftermarket ECU all i need is the ITB's which are few hundred $ injectors and fuel rail.
The stock inlet manifold is bad designed for reducing power and giving low end torque no matter what you do to it it will still be bad at flowing air and fuel even with a 4 barrel mod.
And if you do decide to mod the stock one, don't make the ports bigger just concentrate on rounding off edges and cleaning up the surface finish so that theirs no cast marks, but theirs not much you can do, port it out bigger will make it run worse especially with a stock carb.

phrenology
10-04-2005, 09:13 AM
Besides custom what else we got? Anything that'll fit? Or should I just port the crap outta it (worth it against a custom one?)

All pics located: http://www.3geez.com/showthread.php?goto=newpost&t=46802 (site was down before)

FyreDaug If you are just trying to get it running without the headache of all the FI mods and you want to chuck the emissions controls, you can put a Holley DGV 32/36 on the stock manifold with little modification observe:

http://img.photobucket.com/albums/v106/phrenology/P9030013.jpg

I ported and polished the stock manifold myself like rjudgey said, just a little Dremel on the casting marks to smooth it out, then I sand blasted the finish on the manifold. My friend drilled and retapped the holes to mount the carb and we put a small spacer plate in there.

FyreDaug
10-04-2005, 10:20 AM
Is the carb really gonna be worth it? They arent that expensive on ebay, just wondering if the gains I get are gonna be worth it when all I am doing is switching the carb. That weber seems to be a popular upgrade, but Im still skeptical

phrenology
10-04-2005, 11:00 AM
Is the carb really gonna be worth it? They arent that expensive on ebay, just wondering if the gains I get are gonna be worth it when all I am doing is switching the carb. That weber seems to be a popular upgrade, but Im still skeptical

If you are looking for a power carb upgrade than do a DCOE set up but it will cost you. A used pair will be like $300-$400 plus a hundred in jets and parts to get em' matched then another $250 for the manifold unless you machine one yourself. Don't forget air horns and filters! Linkage too!

Or go with the Weber 38/38 downdraft on the stock manifold but I'm not sure how much you will have to modify it.

FyreDaug
10-04-2005, 03:06 PM
Thats what I'm thinking, why bother with a single 32/36? Will it do anything?

A20A1
10-04-2005, 11:00 PM
psst. 4bbl :)


j/k

rjudgey
10-07-2005, 09:31 AM
Phrenology what exhaust header is that in that picture??

gfrg88
10-07-2005, 09:55 AM
i think its an S&S 4-1 header

rjudgey
10-10-2005, 08:07 AM
no can't be has a join half way down with a flange must be a 4-2-1 probably just a pacesetter with cermakrome coating or if he's luck enough a DC sports stainless steel.

A20A1
10-10-2005, 09:50 AM
DC usually has their "DC" name on a plate tac welded to one of the primary tubes near the exhaust port. Plus stainless would have changed color with use.

And the shine of the metal makes it look coated instead of Stainless.