von

S5 N/A (non-turbo) with a bridge port.

Will a stand alone give all the benifits to a junior bridgeport??? I really dont want to go carb. I want to remain as legal as possible (looking at least)

I want all the manifolds intact except I will swap the S5 VDI with the S4 one for better top end.

Evil Aviator

If you are really sneaky, you can disguise the standalone, much like street racers disguise a nitrous system. You can use a stock AFM for visual effect, gutting it if you like. With the BP, you will probably want to cut the intake manifold open with a band saw, gut the internals, and then weld it back together. You can hide the welds as a "polished" manifold if you take some time with it.

I don't see how you could possibly convert to a carb and fool anybody over the age of 10, lol. Anyway, the standalone will work better, especially since you can change from a smog map to a performance map in a matter of seconds, while retuning the carb would take a long time. Also, the standalone will allow for much better control of ignition timing, and the standalone ignition leads are much more stealth than a dizzy, ignition box, etc., that you would use with a carb.

Some people have been getting better results with the S5 manifold. I have not tried working with one, so I'm not sure what is done to it, but you may be able to search this forum for ideas. Regardless, do NOT use the S4 TPS with a standalone if you can help it. The S5 TPS is much better.

von

Oh good thanks. My concern for the benifits was mainly for horsspower but Im asking because it seems like those damn S5 S curve manifolds would be so restrictive for a bridge port. But you say thats not so.

About the middle manifold on the S4 I was only talking about converting it and nothing else like the TB or whatever so yes I will keep S5 TPS intact. Hm after a bit of searching a year ago on this forum it seems as if poeple got more top end with the middle S4 manifolds because they are straight and dont have the twists like the VDI S5 one does. It makes sense. You dont put tons of twists in your exaust do you? The VDI I think was for a better torque curve not top end or at least once your beyond stock anyways.

One more thing EVIL? when im not racing the bridge port say on the weekends and I drive with a cat and muffler do you think the sound would be quite enoughf to drive to work? See my last GXL listed without the engine work had a straight through RB exaust with just a muffler at the end and cops never ticketed me here in sd. It wasnt loud as everyone says theres is. My billet muffler rocked. Anyways thanks.

White_FC

One thing your forgetting is inlet runner length and how when you change the port timming you should ultimatly change the length/design of the inlet tract.

Here is an interesting read with some very knowledgable people who have experience running a brideport with stock manifolds

von

lots of confusing. Its good info but nobody tells me whats the best for a brige. They talk about hondas,PP rotories,S2000's and 787's V8's but nobody comes to a conclusion so far. STill reading. Hmm

Whats ITR...What IR Velocity stacks, Plenum I thought was stock manifolds but they talk about aftermarket or something. Then they talk about other vocab I dont know about.

von

wow finally finished and still no usefull information. What a waste. Nobody mentions what setup is best for a bridge port. I mean looks like the VDI does NOT like bridgeports according to 1 guy but ok then swap the VDI with the S4 Straight runners and port them??? No usefull info at all.

So im still stuck.

Evil Aviator

I don't suppose it ever occured to you that you would be better off having an experienced mechanic set up your engine? I don't mean to be a jerk, but there is only so much information you can get off the internet, and at the end of the day you may be more knowledgeable, but you are still not a skilled rotary engine mechanic. A bridgeport engine is a very advanced undertaking.

NZConvertible

I'm with Evil. No offence, but some of the questions you asked are EFI 101. If you want this done now you should probably go talk to an experienced rotary workshop about what you want. Otherwise you need to do a lot more research, and not rely only on the internet for it.

Personally I'd never bother with stock manifolds on a bridgeport. An aftermarket IDA or DCOE TB set-up is far better suited to the high airflows. If that's going to present legal problems then you should seriously consider turbos as the practical way to get the power you want.

von

Hm if I talk to a shop I might get biased opinions on whats best. But I will do that. Carb makes sense for high flow but the physics of everything and how it works is so much different. All I wanted to know is what will make more top end power Carb or EFI ? But its such a hard question im guessing because out of 600000 poeple on the forum nobody has ever had both setups optimized for power on lets say the same 2nd gen car. 2500 posts was good enoughf to get me this far and even rebuild my own engine but aparently asking what setup makes more power is just one of those odd ball questions that will forever go unansewered. Thanks for all the links thou lots of good info.

NZConvertible

No it doesn't.

White_FC

Outright power will _NOT_ be effected by either setup, at all, however, EFI is an _infinatly_ better idea.

Evil Aviator

You are missing the point. The process is to tell the shop what you want, and then they build it for you. It is their responsibility to meet your stated demands, assuming that they agree to the terms. Outright power is made by good mechanics and engine tuners, not by some newbie rigging together various parts and pieces. If you want outright power, drop your car off at Mandeville Auto Tech, and then show up a few weeks later with a big check and pick up your new car.

Everything else being equal, the venturi of a carb creates a restriction, while EFI does not. Advantage - EFI. However, if a given tuner knows more about carbs, then that is the way to go.

White_FC

Yes ok, we can get into that area of it.. But then you could just move upto a larger carb...

hehe, my point was basically it's not so much wether you use a carb, EFI or even mechanical injection, all of which could safely produce the same good outright power.

But i'm sure you already knew that, so I'll stop nick picking about details, chances are they have already been lost in most peoples own clouded vision of reality.

Anyway, to the original poster, if you seriously wan't a bridgeport, don't both with the stock manifolds or computer, not worth it.
Mazdaspeed7 (over at nopistons.com) only just had just a (to me at least) mild auxillary bridgeport engine, and that would not even run corectly with the stock manifold/computer. So i'm not sure what you were planning but i'm sure if it was a bridgeport it wouldn't be more mild than his.

But hey, if you wanna prove us wrong, by all means go ahead with it, more power to you.

-Nathan

von

oh no ive gone cross eyed...Venturas, stock ecu's and larger carbs OH MY!!!

See thats what im talking about. What makes sense (carbs) for high flow is now a restriction...If I had a stand alone I wouldnt know any aftermarket manifolds to buy infact with all my searching I dont think I ever saw one to begin with. I already know what im gona do know so its all good you guys helped alot...

Im going to get a stand alone and port the hell out of mmy stock manifolds then swap the VDI manifold with a ported S4...This way I think I solved everybodies problem on why not to use them...This solves all the probs like restrictive venturies, Fuzzy carb ignition, VDI restriction exc exc...Plus I read that long runner length doesent mean less power. So that S curve of S5 manifolds should be ok with a bridge because of physics, pulse waves, negative waves, positive waves and **** that I dont know about so its all good.

NZConvertible

The point Evil was making is that for a given throttle size, a carb flows less than an EFI TB because of the additional restriction of the venturi.
There have been lots of threads about aftermarket EFI individual throttle body set-ups, mainly IDA-style TB's that mount on Weber IDA manifolds. 1987RX7Guy started a thread recently with pics showing the beginning of his installation, and I've posted pics and links to suppliers before.
Yeah it does actually. Long runners improve low-rpm performance at the expense of high-rpm performance; short runners improve high-rpm performance at the expense of low-rpm performance. That's why manufacturers use variable length intake systems, including the S5's VDI system.

nitroracer

iTrader: (5)

see what you guys dont understand .is that i have not yet seen a shop that can do that kinda work for what he wants. in sd they all do turbod 7s. and there are a few to no lil shops around here.. on the other hand theres those porto ricans. that know there **** around here. and will be willing to build a motor for you Von.
on the other hand about the confusen with intake manifolds. i have a friends that has a CNC machine. he will be down to make a intake manifold for you so that you can run the stock tb and standalone..
Von if you have any questions, give me a Bling...
happy rotoring...

von

oh look whos got the hookup. Well ok smarty pants didnt think you were an n/a guy. Hm I can build my own motor but as far as tuning and what manifolds to buy that I guess the purto ricans can do but I thought they were moving?

Evil Aviator

http://www.tripointengineering.com/

White_FC

What do you mean? I know plenty of shops that specialise in getting power out of N/A brideport engines?? some are even cracking the 300hp mark without cutting into the rotor housing at all...

Then again, I'm nowhere near Von, so theres no point in saying who...

But I can still talk about the type of inlet manifolds they use and i'll give you the big tip, they are not long, far from it, nor are they nearly as skinny as even a honed out stock one.

von

haha ya there are alot. Tri point engineering few hundred miles up north then thiers rx7.com ofcourse in texas. Im not stuck on finding a shop anyways I do pretty much anything myself. I do know one shop that I deal with for the little stuff.

White FC...Please give me a link to any FCs running 300hp on a bridge. And thanks for the tip. Links ???Thanks guys.

White_FC

Read this, all of it.

von

Oh ok so thats the setup thats making so much power. Damn 300 with just a BP 13b. Wow

Well looks like im back at square one because I cannot afford 5000 bucks for that manifold setup. But then again I think I will be happy with 240rwp with a carb or usuing stock manifold and bridge. Doesent matter to me anymore. Looks like anything more than 240rwp past 9500 rpms will cost exponentially more in other related parts to sustain those hiegher numbers. Thanks.

NZConvertible

Only a very extreme carb'd BP will reach 240rwhp, and it'll be almost unusable on the street. And you won't get even close to that much power with the stock manifolds.

If you want a 240rwhp road car, get a turbo.

von

what I do with it as far as street driving or daily driver is none of anybodies concern. I simply said I will be happy with 240rwp. If streetport carbs can get over 200rwp I dont see why I bridge cant? Do you ??? Show me somewere were it says I cant. The links I read say they all have.

NZConvertible

What's with the attitude? Do you want advice or not? If this is a racecar, rell us. If it's not, I'm advising you that a bridgeport with that much power will be almost useless as an weekend street car, let alone a daily driver.
Make up your mind. It is 240rwhp or 200? There's a big difference.