Best intake manifold for my s4 na aux bridge?
 

Hey,

I'd like to get some people's opinions on what would be the best intake manifold setup for my FC, At the moment I have a s5 na intake manifold setup with no vdi working and my 6 port sleeves removed on an aux bridge s4 na. I've seen people say a s5 intake setup works great on Stockports but don't really do to well on bigger ports, that true? My other options could be a full s4 na intake setup and we could por it or a s4 lim portmatched to the s5 vdi manifold, i know theres a few guru's around here that can help :) Well heres the list of power mods done to the car:

-S4 NA shortblock
-Rebuild W/RA Components
-Small Streetport/Aux is bridgeported
-Removed diffusers & port
-S5 Intake manifolds
-Full RB Exhaust (header,presilencer,ypipe,mufflers)
-Cone Intake
-Haltech E6K
-Jacobs FC1000
-TII Secondaries

We did a base tune yesterday and got 144whp &108TQ, Ignition break up was all the way across the board and no vdi, 6 port sleeves removed (might have done some good or bad), we even swapped the plug wires and still got break up, any input on that? I'll have dyno sheets tommorow, Thanks alot! heres the bridge:

Personaly, I'd stick a ported s4 lower with the aux port sleeves intact and working (better idle and low end), then get the Racing Beat upper intake (s4 lower to side draft DHLA carb pattern) and bolt on a TWM DHLA style throttle body either 48 or 50mm. Then you can make a air box with the air horns in it with a flat style filter with a TII hood that closes and seals on the box. These were the plans I started to go with (aux bridge, TWM tb etc) when I when I was running N/A, but I sold it all and went turbo.

~Mike............

how much low end did you give up for all this? I would get the vdi and 6p sleeves working again, I thought you guys with a good ECU tune could hit near stock RX8 dyno levels in the 180's with no loss of low end if you good a good set of headers, exahust and intake.

whats your power curve look like? Remember, average power wins races, ask BMW.

I've seen street ported 6-ports do 185 to 190 rwhp with an IDA style intake and TB.

I'll try to get the damn dyno graphs in today, I can't find them right now! :(

-Andrew

I thought bridging only the aux ports didn't work, because of the conflicting resonance pulses in the same intake runner?

And oh man, bridge/peripheral don't give up a *thing* on the low end. It makes more. Lots more. My PP feels like King Kong even keeping it below 3k. In fact, around town, that's the only way to drive it... below 30mph you need to stuff it into 5th to keep the engine loaded enough so it doesn't buck your tooth fillings and U-joints out. It's either that or hold revs up around 3500, or push the clutch in when you're coasting.

The problem with bridge and peripheral ports isn't so much low end power as it is part throttle smoothness. I guess you've found that out. They sure are fun opened up though!

Do you have the completed pictures of yours yet?

Check the website.

The engine runs *great*, it's not using coolant (am using 18-gauge hookup wire for coolant seals), has great compression (awful housings). It just needs better carburetion. The 750 is too large (barely gets into the main metering), yet too small (have to crank the throttle plates open for it to idle). Kind of an interrelated problem. I'm getting a 450cfm carb and going to rework the throttle plates so it'll idle. :)

I didn't see any in car pitures of the engine.

What you need is EFI and a big idle air control solenoid ;)
Grant

where in socal r u

Riverside, but i found the dyno sheets, time to upload.

Ok here they are, i made them big because you can barely see the colors/lines

http://www.filefarmer.com/andrewruiz/asdf.JPG

http://www.filefarmer.com/andrewruiz/asdfg.JPG

Seems kinda pointless. I mean, you can see the engine better sitting on a pallet than in an engine bay. :)

I do have pics, including pics taken during the swap, things like: empty engine bay, new engine on hoist, many bottles of Kirin Ichiban and Guinness Stout on the roof of the car, engine in chassis, putting all the niggly crap back in, etc. They're probably never going to make it to the website since I am almost out of room as it is, and I'm always hitting bandwidth limitations too.

thats with the aux bridge?

i thought that would have made more power.

i think you may gain some useful insight if you contact the user Kahren on this board or on www.nopistons.com

i don't know him personally, but i do know that he put together a bad-ass stockport with a custom intake manifold. it would certainly be worth having a chat with him.

hope that helps.

have you tried running without the Jacobs to see if it may be part of the ignition breakup issues?

That exactly what me and my tuner were thinking, I just got my msd 8.5's in but my injectors were supposed to be back from being rebuilt but i sent it to the wrong adress so I had to repay for postage blah blah wait another week so it's going to be a while before i'm back at the dyno tuning it.

-Andrew

Edit- i'm sending kahren a pm and maybe he'll respond :) Thanks for the help!

Okay then here's one (this air filter was stolen when my car was broken into, BTW)

http://img.villagephotos.com/p/2004-...-underhood.JPG

And the first start video is in www.vosko.net/media/pj/ if you want.

One step forwards, two steps back. I need to put the doors on before I can bother with the carbs. Or the exhaust. Or the floor.

You got a couple of specs of dirt in that engine bay! ;)