Sorry this is a little lengthy. I am long winded. Great info though so please read it and try it!

This is my way of improving airflow taken to the next level. Those factory secondary injectors are in a horrible location as we all know. They block airflow and make it very turbulent. This may have been done to help fuel atomization but at about 4K rpm where these come on we don't need help from turbulence. I had a welder friend fill these holes in for me. It only took him a few minutes and he did it for free! The inside of the runners is now ground out smooth so there is no more restriction. I did do the manifold porting like dre2000 has posted but I revised the shape a little and blended farther down. I port everything including the plenum/dynamic chamber. Not bad stock but could be better. I physically cut the plenum in half vertically and hollow the whole thing out to one giant plenum. It is then welded back together and the outside ground smooth and sandblasted so no one can tell. SHHHH!!! Airflow through the secondary runners was pretty good stock since it was a straight shot through. The primaries however had some problems. Since there is one big chamber now there is a much smoother distribution of airflow through the plenum. Much better to the primaries. Since airflow is so good through this open space flow is not affected to the secondaries. It still flows as good as it did when they were straight through. Look closely and you'll see where my secondaty fuel injectors are mounted. Really easy to do this with only a few dollars in parts from a hardware store. Fuel fires straight down the upper runner at high rpm's and since there are no actuator rods in the way airflow is increased again. The stock secondary fuel rail is slightly modified. The holes for the injectors is tapped with 1/4" pipe tap (have fun finding this!) and brass barbs are screwed in. Fuel line is run from here directly to the injectors and secured with hose clamps. Works great and no leaks. The injectors are held down with a flat piece of bar stock (not pictured) which is screwed into the lower manifold. The plenum and the lower manifold are polished inside completely. Almost looks extrude honed. I can't reach some of the middle piece to polish internally but I did get about 75% of it. While my plenum was out I modified the intake to accept a 75mm Mustang tb. Huge airflow. If you do the math it is actually the same throttle plate area as the 3 combined blades of the stock tb but it still flows better due to less turbulence. Idle is now controlled using a T-II bac valve since this is where the adjustment screw is on them. I have adapted the factory tps to work with the new tb.

Intake makes a nice sucking sound now. A little like my Honda but with the added benefit of being able to move faster! Throttle response is super quick. Car revs faster and pulls harder everywhere.

I can do the fuel injector mod on any '86-'91 n/a intake manifold. Takes about a day to complete.

I can do the plenum mod on any '84-'85 GSL-SE, '86-'91 turbo and n/a plenum. Working on a T-II one right now for BDC. Less turbulence internally. Air distribution is much more uniform. The plenum retunes the intake as well but I'll let you guys figure out how

Here are a couple of low quality pics. I'll post more as I do more work on them.

 

Picure loading problems bear with me I'm working on it!

 

Hopefully this will work. All my pics seem too big. This is the best pic anyways. This is still an under construction picture so it is missing a couple of things.

 

Don't mind the mess in some spots its not done yet!

 

Here's another view. Look really closely and you'll see I adapted the S5 upper to an S4 lower. No problems with egr passages when changing over.

 

WOW!!

How much would you charge for this on a 88 T2 manifolds?

 

I have a couple of T-II manifolds lying around that I could modify. What exactly do you want done to it? Do you want to keep the stock throttlebody or are you going aftermarket? I can hollow out the plenum and port and polish the entire intake manifold internally and still retain the stock tb if you need it. I haven't tried to relocate the injectors on the T-II manifolds yet. It will require aftermarket injector bungs but should be pretty easy. To just hollow out a plenum I can do it for about $150 plus shipping. Since I already have a couple I will just ship the new one out when I get the old one. Pretty cheap I think especially for the amount of work involved. That price is to only do the plenum mod. Duplicating my n/a setup would be about $400 and require a little time.

 

This application seems feasible. To bad you don't have dyno run results on the before and after. Or do you?

 

Just a dyno after would be great, that looks awesome, gives me some ideas

 

what aftermarket throttle bodies are availible? links would be nice

 

Wow.... nothing holding down the injectors, or the lines that run 40 psi through them.

Not possible on a TII manifold either... Turbo getting in the way and all.

I'd like to see if there are even any gains from this mod. The fuel injectors were never designed for direct injection like that...

 

Looks to me like he custom fit an aftermarket Mustang TB.

Other than that, BDC sells ported ones, and RP (rx7.com) sells bored ones.

Neither are worth the money, as the stock TB is hardly a restriction.

 

Not that im supporting this mod, but he did mention the hold downs for the injectors he made where not in the pictures...
I assume he's got some L-shaped peices to hold each one down...

The stang TB would be nice on a turbo application, just becuase it would be eaiser to connect aftermarket IC piping to it-

 

Actually there is a bar holding down the injectors and clamps on the lines. They just aren't in that picture.

The fuel injectors were never designed for injection like that? Uh...go look at your primaries. If I wanted to I could adapt them to fit the oil injector holes straight on the rotor housings themselves and they would work great. The gains are very nice above 4K rpm. There are no more of those actuator rods in the way that everyone foolishly and mistakenly leave in place when they 'wire open' the 6 port system. You gain nothing without removing them! Since my upper ports are permanently radiused fuel fires straight down the runner and into the engine. At that high of an rpm it doesn't matter where the injector is (to a point). The main reason it works better like this is because air (and fuel) flow easier through the lower side ports than the upper. This is due to the tighter turn radius in the lower manifold. Because of this less fuel is injected into the engine near the end of the intake cycle before the port closes. I took care of that. Also the inside of my middle manifold no longer has those airflow disturbing injector bumps.

Location does pose a problem for forced induction cars but as you can see this is not one of those. Not everyone is aaroncake! I am going to find a way around that though. One problem at a time.

Yes I did use a Mustang tb. 75mm unit from Summit Racing, uh.. or was it Jegs? No matter you get the idea. The stock tb is very good. All 3 plates together combine to equal what would be a 75mm round unit. The stock one doesn't quite flow as much though (very close when ported). Break out the manometer you'll see. I almost did use the stock one though but I really wanted the effect! BDC does great porting. I was at his place last weekend and saw a couple. A larger bored out tb is pointless especially if you still have a stock ecu/afm. Can take the tb porting one step farther though by using button head screws on the plates and thinning the shafts. Modifying the secondary plates to open with the primary (also opens them farther!) is a great idea.

The T-II manifolds I'm working on at this time are using a different secondary location. They are moved to above the plenum chamber firing horizontally towards the passenger side of the car. You can not use the stock intercooler location though. If you are willing to do this then you probably aren't anyways. The hard part is grinding out the factory secondary injector mounts from the T-II lower. PITA but I have a bit that can reach.

My setup is installed on my streetported 1st gen GSL-SE. Should work the same if not a little better on a 2nd gen. since all this is going through my really small air flow meter until I get a standalone ecu. Oh yeah my afm is ported too but I'm sure someone will tell me that there will be no gains from it so I won't post how to do those.

 

i read about a guy who built a y pipe and put two afms on the car, only 1 is hooked up to the ecu....

mike

 

I wonder how he made that work? hmmmm.....

 

I must say, I realy like the idea of moving the injectors. Those bumps realy suck. We need some dyno results of before and after. If these things will make anouther 10+rwhp, I buy a setup for shure! Keep us upto date, and some more pictures of the way you secured the injectors would be great. Later, CJ

 

Are you going ot make this like the intake porting thread? A few more pictures (like of the inside of the dynamic chamber) would be REALLLLY appreciated.

I've never seen anything close to this done before, but it looks awesome and I'd love to try it out! My friend Levi is about to get a S4 w/o 5/6th, so I'd think this setup would be awesome for him. THX

 

Rotarygod being that ive known you for a good month i really hate you man....here i am sitting pretty thinking wow i had a nice stock s5 setup and you go and do this.....you are the man no doubt

 

No joke. After seeing this, I can PROMISE you, I've spent over an hour looking at that setup.

The injectors wouldn't be hard to do at all, it's the dynamic chamber, and the Mustang TB.

I'll probably do the TB and Dynamic Chamber on mine, if I can figure out how to. But, I want to keep my low-end torque, so the 5/6th ports are staying.

My friend Levi however, will probably want to do it all. But we can start out w/ the secondairy re-location first. Shouldn't take long to do at all. Owning a Welder, Cutting torch, Etc. is GREAT. I just can't figure how he cut the Dynamic Chamber in half...???

 

Could you do me a favor sometime in the near future, and measure the baffle of the TB? I've got incidious ideas.

 

this looks great.. why did u decide to put the S5 upper intake instead of the S4.. the S4 is better after porting... will the mustang TB fit fine on a S4 compare to a S5?

 

It should fit the same. TB's are the same, so I'd imagine the Dynamic Chambers are the same.

I'm sitting here, sketching dynamic chambers (easily made) and coming up with ideas.

Take a S4 intake, fill the injector holes. Take the secondairy fuel rail, cut it, and extend it so the injectors will fit in, and be able to be put into where they are (eliminate the need to tap the rail) Make a plate to mount the fuel rails where they need to be (boes across the place where the ACV used to be. Custom Dynamic Chamber, and AWESOME. Only problem is exhaust heat... but, heat-wrap the manifold, and fuel-rail, make a heat sheild and problem solved.

Hehehe, this is such an origional idea... CONGRATS ROTARYGOD!!! You've inspired me!!!

 

Why and how did you remove the ACV?? Im not familar with what it actually controls.

Is removing the 5/6 ports really going to kill low end torque that much?? I would like to do this setup so I can remove my airpump, ACV, and the 5/6 ports w/actuators.

 

I will take pictures of the inside of a dynamic chamber before and after this week. I am about to do a T-II so I'll shoot it then.

I thought about using the S4 manifold but I've never had an S5 one before so I thought I would play with it to see what I can do. I've done an S4. They work great when done. An S4 was the first one I did a few years back that relocated the injectors. Thats how I know it works. Rotary airplane guys like to do this injector mod too! It is really popular among them and they hold their engines at 6K rpm while flying.

You guys don't need the Mustang tb to get the performance. The stock works fine. The mustang one flows slightly (very slightly) better than stock but I just wanted to be original. Easier to make an intake pipe to match with it too. I did make the factory tps fit and work on it. The S5 tps is slightly different so I don't know how well I could adapt that one.

If you guys try this make sure you know a very good TIG welder. My welder works on welding jet engine turbine blades so he is very good and quick. Have fun cutting the dynamic chamber open! DO NOT USE A CUTTING TORCH!!! It took a little while to figure out an easy way but then it just hit me. 5 minutes and I can get a clean cut. Its all about the right tools. I can do an entire intake mod (everything mentioned here) in one full day! This includes welding it back together and cleaning it up!

Dynamic chambers are not the same. The S5 flows the best. The upper throttle plates feed their own intake runner exclusively. No open plenum area for them. The lower single plate opens to a rough plenum chamber and feeds the primary runners. This is where the problem lies. The GSL-SE, S4, T-II dynamic chambers all resemble each other internally. I've even internally modded a 3rd gen manifold although I don't recommend it. That one flows as good as it can in its stock form.

I have seen the fuel rail moved down before but I wanted simplicity and ease of installation. It just looks damn cool this way too! You should see it with braided lines.

The ACV was removed because I object to the Texas emissions laws. You can still pass without it if you know what you are doing. Got one to pass once with no cat! It did have a Haltech though. The ACV holes were filled in with plastic steel epoxy. The pictures show them before I trimmed and sanded it down.

Low end torque is noticably decreased when you disable the auxillary ports. If you put a header on after you do this you will find that you gained it all back. Of course if you keep the ports working and use a header you will have a hard time keeping the wheels planted at lower rpms.

I'll get a picture up of how I did the fuel rail. Hell I may as well show you guys how I ported the afm although I know someone here will flame me for it.

I do need dyno results but I can't afford to keep going everytime I make a change to something. I'd be there everyday. My goal is to break 200 rwhp w/o the aid of nitrous or forced induction. I've seen 195 hit and that was with less mods than I have. My primary intake port runners are slightly smaller though since I have a GSL-SE. I wish I would have used the exhaust sleeves!

You guys are killing me with questions!