Alternative Port EFI IntakesThis board is for tech discussions and questions about aftermarket port EFI such as the HSR, MR, SR, BBK, FIRST, etc.
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I'm starting this thread to show how we are going to modify a Super Ram intake system for high flow and high rpm operation. This particular unit is going on a 406 motor so it will need the flow and does not need a long runner at all as he will have all the torque he needs.
The pictures are of the initial weld up areas. The intake manifold is going to get the same treatment as done in the thread by JerryWho. Basically we are going to reshape the roof entry into the head and open up the cross sectional area befitting that of a 406 motor. Initially I'm looking at a CSA of around 2.3 square inches where the runner meets the head. I will revisit PipeMax to finalize my decision.
Regarding the runners we are going to siamese them with only two inches of runner left. With the welding I will be able to make a straight cut across for maximum cross section area for the siamese portion. The runner area that is left will be opened up as much as posible. How much is yet to be determined.
Sounds like some very interesting work as I'm looking into a larger CID engine myself. Do know what kind of heads/specs that will be used? Would be interesting to see what kind of combo that has been picked out and if its a cali streetable beast!
Before and after numbers would be great. Either flow, hp or track #s. Excellent work!
__________________ '91 GTA L98
"...the current GTA carries on the idea of the first Trans Am proudly and deservedly. It's still the most mature and sophisticated ponycar.
It still has character. It still has muscle. And it's still worthy of the name." -Car Craft, 1991
My ride and mods here: http://www.cardomain.com/id/erpichon
It will be California smog legal. We have before numbers but they are not with the better exhaust system. So with the next dyno the car will have the upgraded exhuast and intake system.
The heads are modified AFR's. The cam is the XFI280. The exhaust will be by DynoDon. The motor should put down well in excess of 400rwhp.
I have one side hogged out on the mill and siamesed with 2 inches of runner left. I have shown the one side with the hole where I punched through. This is at the end of the weld area so more welding is needed.
If the owner of the runners options for some more work I fully believe we can open up what remains of the runners to 1.8". That should flow some air. Here are the before and after pictures.
Last edited by 1989GTATransAm; 07-24-2008 at 09:16 PM.
Don is correct. Also most people already own the runners and the modifications are not hard at all if you have access to a mill. It looks like modifying them will not be that hard compared to the SLP runners.
The owner has agreed to go for all the gusto on these runners. So we will be able to show what can be done and how to do it. When done I fully expect this system to flow well in excess of 300cfm.
That looks like its going to be a healthy motor. I do like your train of thought when it comes to the runners.
Question :
Are you going to port out the manifold as well? Which gasket will be used 1205 or 1206 or?? What size injectors will be used?
Ok so that was 3 questions! This kind of build will benefit from matching the mani to the head as well. This is an interesting project do keep the updates coming as they unfold.
Yes the intake manifold will be ported out. On the inlet side they will be opened up to a minimum of 1.800" to match the runners. Regarding the head side they will be opened up to somewhere around 2.3 square inches of cross sectional area. From our experience that should equate to somewhere around 320cfm of flow and still maintain the correct velocity for the motor.
We will be using a 1205 intake gasket. It has plenty of cross sectional area available to do the job. I believe the owner has 30# injectors. Maybe 36#s.
Regarding matching the intake manifold to the head is a discussion all its own. There are any number of people who subscribe to the theory that some steps left in place is good for helping to prevent reversion on a street oriented motor.
I have opened up the inlet to the Accel intake manifold to just over 1.800". This is to match the runner openings which will be at 1.800". By the way the runners are at the welders for more modifications. Pictures to follow.
Here is a picture of the intake manifold. The port on the far right is fully opened up. The one next to it is pretty close and just needs to be brought out to the final size. The two ports on the left are still in the stock configuration.
Don is correct. Also most people already own the runners and the modifications are not hard at all if you have access to a mill. It looks like modifying them will not be that hard compared to the SLP runners.
The owner has agreed to go for all the gusto on these runners. So we will be able to show what can be done and how to do it. When done I fully expect this system to flow well in excess of 300cfm.
What do you figure the area of the runners will be ?
Hi Reid. The runners are for another car. Mine has been together for awhile now. I don't expect to take it apart until early next year for the next major round of modifications.
The id of the runners will be 1.800 inches. That works out to 2.54 square inches. That will taper down to around 2.2+ square inches inside the intake manifold where it meets the head.
More Pictures. I was hoping to be able to show the new entry angle into the head and how much material has been removed. Hard to show on the two ports that are 98% finished. Middle picture.
The other two ports with the one showing the cut by the end mill gives a better idea. Far right picture. I would say there is around a 1/4" deep of aluminum removed. Maybe more. The openings are a close match to a 1205 gasket.
looks good, i remember when i ported my accel lower. i had it swallow a golf ball whole for a good 1/4 the way in before i couldnt reach anymore with the dremel
Update: The runners have been out to the machine shop and to the welder. In the pictures you can see the tubing that was welded on to extend the bolts and enable the larger boring of the runners without going outside. With the longer bolts it makes it easier to install the runners.
Also looking down the machined out runners you can see the restricted area. The area is actually a lot more restricted than it looks in the pictures because a good portion of it was machined away. From what is left it does give you a good idea. This will really enhance the flow of these runners. By the way the inside diameter is 1.800". This will allow for a decent taper down to where the intake manifold meets the head.
The modifications performed will have no effect on the EGR, fuel rails or injectors. I suspect the rate of taper will be around 2%. Hopefully this will increase the VE a smidgeon.
Between the exhaust upgrades which includes a 4" Mufflex cat back and the opened up Super Ram I believe he will be well into the 400rwhp number. His car will be capable of deep 11's.
I have been working on the runners today and decided to widen the opening into the runners. It looked to me that maybe the outside runners could be "hidden" somewhat for good airflow. So I widen the runner entrance a 1/4 inch to the outside. This opens up the airflow to the outside runner quite abit for even air distribution.
In the picture the runner entrance on the right has been widen 1/4". The one on the left is still stock. Maybe look at the bolt holes for reference. Here is the picture.
Here are some pictures of the runners. They are pretty much finished. Just some minor clean up. These babies will flow some air. Here are the pictures.
Well there is a problem with the before and after on the motor. With the previous dyno runs the motor was seriously handicapped by the single 3" cat back. The back pressure was pretty significient and obvious. He is going to have Dyno Don install a Mufflex 4" cat-back along with some other exhaust upgrades.
With the intake improvements and the exhaust upgrades there can be IMHO anywhere from a 30rwhp to a 50rwhp horsepower improvement. So it will be hard to give a percentage to either one. You can tell the intake improvements are significant compared to the stock unit. The motor will breathe a ton easier.
Well there is a problem with the before and after on the motor. With the previous dyno runs the motor was seriously handicapped by the single 3" cat back. The back pressure was pretty significient and obvious. He is going to have Dyno Don install a Mufflex 4" cat-back along with some other exhaust upgrades.
.
Ha Ha!
yeah, only made 385HP 435 TQ to the RWS thru that "bad" exhaust.
This is a California car with all of the smog equipment in place.
The exhaust is the same as the last time the car was on the dyno before the Super Ram mods. Dyno Don headers, 2 1/2 y-pipe, single cat, and 3 inch SLP cat back.
Dyno Don says with more tuning we could have got even more out of it today, however I did not feel like continuing.
Dyno Graph. The red is the previous best before the Super Ram mods.
'91 GTA L98
Here are the pictures. 
