When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
From: Arizona - If you don’t know CFI, STOP proliferating the myths around it...
Originally Posted by ghoastrider1
For you guys talking times and base runs. I know this isn't the same but... my 86 has a jillion miles on it and of course the engine needs a freshen. Anyway. when I take it to the drags here in Indy, my runs are usually faster than 14.5 wirh the fastest being 14.03. New mustangs , cameros and other "new" cars, outrun me. So guys. go out there and kick some ***.
Yep, DA has a lot to do with ET as well. You are lower than me I'm sure on a days average. The closer you get to a sea level DA, the faster you get. Someday I may take the car out to CA or something and give it a whirl and see what it does. In the meantime, a DA around 2,500-3,000' puts me squarely in mid 12 to 12.7 area right now depending on launch and track prep..
Ok, switching gears slightly - re: the Renegade, if you were to retain use of the EGR, I don't see how the exhaust gas gets circulated to the runners from looking at a pic with the top removed. Is there some central port I don't see? The reason I ask... even though I've (for now) given up on the Renegade due to all the cost and quality drama, I did just pick up a complete Crossfire setup off CL locally for a good price. I'm going to attempt to port it. I recognize it won't be "flow-equivalent" to a Renegade, but I'm not interested in building a monster, just something with a bit more oomph. Anyway, all the porting pix I've seen remove the EGR hump (understandably) and cut it back to the manifold wall. If I wished to retain the EGR to retain stock appearance, would it still work ok? I suspect the reciruculated exhaust would mostly go down the nearest runners, but is that a problem and is that how the Renegade does it?
From: I tend to be leery of any guy who doesn't own a chainsaw or a handgun.
Originally Posted by cuisinartvette
Id love to see a carbed plate be made....not like i have extra $ floating around but suregot the mind going.
Any crossrams out there are too old, dont take a large port or tall valve covers. I dont care whats practical just looks awesome.
That sounds like an easy project. Are there any odd issues that I'm not considering?
I did just pick up a complete Crossfire setup off CL locally for a good price. I'm going to attempt to port it. I recognize it won't be "flow-equivalent" to a Renegade, but I'm not interested in building a monster, just something with a bit more oomph. Anyway, all the porting pix I've seen remove the EGR hump (understandably) and cut it back to the manifold wall. If I wished to retain the EGR to retain stock appearance, would it still work ok? I suspect the recirculated exhaust would mostly go down the nearest runners,
I agree with you about the EGR gasses. The "hump" is a duct to route the gasses to the central area of the manifold to distribute those gasses somewhat uniformly, and I doubt that the location of the duct does much to degrade the performance, since that's such a large plenum. Since the two throttle bodies are synchronized, there shouldn't be much "cross-flow" in the plenum.
In addition to opening the ports. the runners can be shortened to aid breathing and also to raise the rpm of the hp curve. All good!
I agree with you about the EGR gasses. The "hump" is a duct to route the gasses to the central area of the manifold to distribute those gasses somewhat uniformly, and I doubt that the location of the duct does much to degrade the performance, since that's such a large plenum. Since the two throttle bodies are synchronized, there shouldn't be much "cross-flow" in the plenum.
In addition to opening the ports. the runners can be shortened to aid breathing and also to raise the rpm of the hp curve. All good!
Thanks for the reply. Just to clarify, I was planning on removing the hump, but was wondering what would happen if I leave the external EGR stuff in place. So the system was basically still functional. Seems like all the porting examples I've seen block off the EGR port with a plate. When I look at the Renegade, I can't tell how the EGR gasses get distributed.
Re: runner shortening, any recommendations on how much to take off?
Thanks for the reply. Just to clarify, I was planning on removing the hump, but was wondering what would happen if I leave the external EGR stuff in place. So the system was basically still functional. Seems like all the porting examples I've seen block off the EGR port with a plate. When I look at the Renegade, I can't tell how the EGR gasses get distributed.
Re: runner shortening, any recommendations on how much to take off?
Here is a photo of the Renegade arrangement. You should be able to see the port where the exhaust gas enters the plenum chamber.
PS. If you shorten the runners too much you will loose bottom end torque. This may not be a problem considering the other gains you will make. Also some people will suggest drilling holes along the runners but the general consensus is that that’s a bad idea.
Last edited by GregMartin; Oct 5, 2019 at 07:52 PM.
From: Arizona - If you don’t know CFI, STOP proliferating the myths around it...
Originally Posted by GregMartin
Here is a photo of the Renegade arrangement. You should be able to see the port where the exhaust gas enters the plenum chamber.
PS. If you shorten the runners too much you will loose bottom end torque. This may not be a problem considering the other gains you will make. Also some people will suggest drilling holes along the runners but the general consensus is that that’s a bad idea.
YEP! There ya go Greg! The EGR port is inside the plenum area. We did away with the shrouded EGR that GM put into the that area for a reason. Works just fine. I'm still wondering about this HUMP thing that you guys are talking about?? Are you maybe referring to the top plate large hump? If so, that has NOTHING to do with the EGR, its the vacuum port just like the stock one. There is a LOT of modifications to that manifold that is NOT obvious to the casual observer to make it very good at what it does and was also developed by a leading world wide manifold developer, not just put together on an idea and a prayer. We did a lot of 3D modeling and flow testing with that piece as well.
Are you guys talking about the Renegade runners and shorten those? I hope not, you will destroy the manifold, so I'm assuming you are talking about a stock one?
It depends on the DA, but 106.7 to 108.7.
Last edited by Buccaneer; Oct 5, 2019 at 10:12 PM.
Thanks guys, that answers my question. Buccaneer - I think "the hump" is the same as the shrouded EGR as you referred to it - the big pile of aluminum that goes from the EGR port half way across the plenum. My question was - assuming a Renegade is the optimum solution for the manifold and it still allowed use of the EGR - how did it route the gas. I'm just going to try hacking up a stocker first ( since I have one to hack up) and if I chop the EGR shroud back all the way to the plenum wall will it still work ok. If you're suggesting it doesn't mess anything up, that's good enough for me!
And yes the intake runner shortening is relative to a stocker, not a Renegade...
From: Arizona - If you don’t know CFI, STOP proliferating the myths around it...
Originally Posted by swamp21
Thanks guys, that answers my question. Buccaneer - I think "the hump" is the same as the shrouded EGR as you referred to it - the big pile of aluminum that goes from the EGR port half way across the plenum. My question was - assuming a Renegade is the optimum solution for the manifold and it still allowed use of the EGR - how did it route the gas. I'm just going to try hacking up a stocker first ( since I have one to hack up) and if I chop the EGR shroud back all the way to the plenum wall will it still work ok. If you're suggesting it doesn't mess anything up, that's good enough for me!
And yes the intake runner shortening is relative to a stocker, not a Renegade...
Thanks,
Steve
It does matter on the EGR on a stocker. That is one of those mods we did on ours and incorporated other things to counter the stock one in development and flow testing on a bench, sorry. Hack away and see what you come up with.
It does matter on the EGR on a stocker. That is one of those mods we did on ours and incorporated other things to counter the stock one in development and flow testing on a bench, sorry. Hack away and see what you come up with.
Maybe that's why all the ported stocker pix I've seen show it with a EGR block off plate. Do most Renegade users retain the EGR or block it off? Pros & cons? NYS doesn't care about emissions on a car of this vintage (well, maybe they care, but they don't check it as part of inspection).
From: Arizona - If you don’t know CFI, STOP proliferating the myths around it...
Originally Posted by swamp21
Maybe that's why all the ported stocker pix I've seen show it with a EGR block off plate. Do most Renegade users retain the EGR or block it off? Pros & cons? NYS doesn't care about emissions on a car of this vintage (well, maybe they care, but they don't check it as part of inspection).
As far as who does what to what on the EGR, I really couldn't tell you. I do not use mine and haven't used it on two motors now. You honestly don't need it and just one more thing to go wrong and buy more parts. I made my own plate, look store bought.
Do most Renegade users retain the EGR or block it off? Pros & cons?
In theory, the pros are reduced emissions, better fuel economy, while cruising. EGR doesn't function at (or near) WOT, so it won't impact power one way or the other.
Cons; Like Buccaneer said; an item that may need fixing someday? I left mine on my car. If the valve had failed, I'd have probably eliminated it....but it never did.
Mine was full of carbon and gunk. I ordered a new one from zip and the sent me an 85 instead of an 84. Too much postage and stuffing about to sort out so I went down to my shed and made a blanking plate. I’ve had no issues.
From: Arizona - If you don’t know CFI, STOP proliferating the myths around it...
Speaking of the Renegade. There has NEVER been a top plate gasket for the Renegade...Until NOW! I finally went through the trouble of creating one that would fit correctly. I have the material now as well as of today and will try and laser cut some out tomorrow if I have time. If not, I will do that Tues. So, for anyone that may want one, the LONG wait is over and soon will be available. I would have done them today, but was up in Prescott AZ for the big annual corvette show and didn't get back until late.
I don't think I could use the gasket on mine... my air cleaner lid already beat the crap out of my underhood side with just rtv on the top plate, the extra thickness would make it worse I assume?
From: Arizona - If you don’t know CFI, STOP proliferating the myths around it...
Originally Posted by 84 4+3
I don't think I could use the gasket on mine... my air cleaner lid already beat the crap out of my underhood side with just rtv on the top plate, the extra thickness would make it worse I assume?
Really? This would be the first time I have ever heard of someone with an 84 running a Renegade that had issues of it hitting the hood with airbox.
