21 WHP after Manifold an Throttlebody Upgrade

Well, I'm reading the preludepower.com forums from time to time and I have come across this:

http://www.preludepower.com/phpBB2/v...ghlight=21+whp

The guy poster his intake manifold and Throttlebody. He also added a spacer and got +21 WHP out of his B20A5

I know that the A20A and B20A5 have a similar really restrictive intake manifold. The JDM Accord B20A has the same intake as the A20A.

We really never got any dyno numbers out of intake upgrades on early Honda Engines but I think this is quite good news. I'm sure that similar or better numbers can be acheived on your A20A/B20A in you upgrade to a newer B series manifold and throttlebody!!

I just thought I'd share

I plan to upgrade mine over the winter if i get her going before hand so i can verify gains on a turbo charged b20a if i get to hit the dyno soon. The good news is i found a dyno really close to my girlfriends house so i plan to hit them up if i get the break in completed.

i think one of my friends is buying some stuff off of that Too Fast guy. that is quite a nice gain

Can anyone tell me the purpose for the spacer? and anybody has do it to the a20 engine?

The spacer is to add a bit of velocity to the air.

Increases plenum volume

Yeah I think you're right Mike :D

Are you guys sure the spacer helps? We had a big discussion about it on AIM a while back and it seems the general consensus was that it wasn't really going to help our engines because of they way the intake is setup(Multiport).

Please explain more about the spacer. Where exactly does it go; between the TB and the manifold? And if it is just to increase the plenum volume, wouldn't the 1" spacer have provided better results?

Yeah I was the one talking about the TB Spacer on AIM a long time ago. I put it on and man I can't tell a difference other than a funny sound that sounds like a blow off valve everytime I shift while WOT. I didnt get better gas mileage like it said either. I have an H23A1 motor and I'm sure my intake manifold and head could use some better flow. Basically all stock honda stuff could use better flowing parts. I would like to upgrade my intake manifold on my h23 prelude but I don't want to get OBX stuff and I will probably either get a JDM H22 VTEC with LSD 5 speed or just convert to VTEC using USDM parts.

-Mike

I just thought I would add my results from my experience with my TB spacer. Basically our discussion before came down to this. Carb and TBI are the only types of motors that can really benefit from the spacers.

I dunno how a spacer would really help on a MPI setup because the fuel is not mixed until the end of the manifold, but i know it does help on carbs because the spacer helps with fuel atomization, but on mpi wouldn't see it helping much if at all...I think the power gains he was getting was just the different manifold and tb...Plenum volume shouldn't matter much either because once the pressure is decreased from the valves opening, the air still has to flow through the tb and thats gonna be the same rate spacer or not...But thats just from what i know, I could be wrong, but it just seems logical to me

Yeah, that was kinda my thinking too. I could see maybe it acting like an extension to the runners so as to provide the same effect of having longer runners, but if it is before the secondary butterfly valves, would it have that effect?

geez, that's pretty damn efficient!

Quote:

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Originally Posted by 88accordhb

geez, that's pretty damn efficient!

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I'm not really sure how that helped or what you were even reffering to.

Thanks Mike for the extra input. I wasn't exactly clear on why it wasn't going to help. But unless someone else has different input I guess we can eliminate that spacer as the cause of any of that extra hp.

Quote:

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Originally Posted by HostileJava

But unless someone else has different input I guess we can eliminate that spacer as the cause of any of that extra hp.

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Unless you're staying carbed :D.

The spacer DOES help. It's been dyno tested so...

Quote:

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I got here about 11:30am this morning and we imediatly started, getting my car right on the dyno for some baseline number

115hp @ 6100 rpm and 109 tq @ 6150rpm

here is waht everyone waited for, stock plus a 60mm Tb

122hp @ 6200rpm and 115 tq @ 6200 rpm

more results to come with some graphs later... back to work

ok, took the tb off and just added the 1/2" & 3/4" spacer with no real gain, less than 1 hp and no tq at all. So i tried the 60mm TB plus each spacer here ya go:

60mm tb + 1/2 spacer

123 hp @ 6200rpm and 118 tq @ 6250rpm (+1 hp)

60mm tb + 3\4" spacer

125 hp @ 6250rpm and 120 tq @ 6300 rpm (+3 hp)

60mm tb + 3/4" spacer + intake

136hp @ 6300rpm and 127 tq @ 6275rpm!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

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You see, the 3/4 inch spacer will give 3 WHP and 5 lb of torque if mated with the 60 mm tb.... Not bad for a part so eazy to replace.

Quote:

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Originally Posted by carotman

The spacer DOES help. It's been dyno tested so...

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I didn't read the whole thread, but did he dyno with and without the spacer and see a difference? Is there intake setup for FI the same as ours?

yes it's really similar. The TB has the same size and the intake uses a IAB bypass valve.

Note that the intake was just ported. He didn't change the intake at all.

Did he test the spacers with the stock tb?


Increase plenum volume would slow the air more... building pressure right? But then it's usually before the TB where this would help.

Intake could be responsibe for straightening out the air more.. or effecting the negative or positive pressure... as compared to having the TB open to the atmosphere. Cause there are intake pulses just like exhaust pulses...

I'm not too keen on all the dynamics though.

Also I wonder if it was a heat spacer?

Those Phenolic stuff should help drop intake temp slightly... so will the CAI.

i have a carb accord i know older muscle cars use them below the carb is that where the spacers go i dont really know much about them but if it gives that much power boost then ill give it a try

For carb applications yes alboy. For FI applications it goes right after the Throttle body and right before the intake manifold.

so what type of spacer should i get then i looked on ebay for some and theres a lot to choose from which one would fit on our cars :sadwave:

how much power do you think our engines will get with a spacer

There isn't a company that makes them for our cars. I have one on my 94 prelude si. The spacer I have on my carbed accord was custom made.

how hard is it to make a custom spacer i was wondering maybe could you buy one and modifly it to fit somehow

you'll need a dremel and drill and a blank phenolic plate... I'm not sure if it will splinter... or if the shavings are dangerous to breathe in or not.

Thing is our carb already has a spacer... but it also has a coolant hole that feeds coolant thru the base of the carb... so you might want to try disabling the coolant flow to the carb from both ends.

I think the coolant idea thru that plate is to keep the carb from icing. Most of the older carbed hondas I have had carb iced at some point. Usually in the mid 30's on a damp morning like on your way to work.errrr dont miss those days. I had alot of 79,80 Accords.

wp

I haven't iced my carb once since I've had my accord. I got it in 2000 too.

You should make a how to on the spacer for carb and efi people.