built exhaust using some modified stock parts. headers to modified y pipe to 3.5" center pipe with 3.5" high flow cat . modified stock rear y pipe to high flow mufflers. didn't go with bigger pipes ,because I didn't think it was needed for this setup. Will have to change if renegade manifold ever comes back. can install stock starter with these headers.
second picture shows fabricated bracket for external fuel pressure regulator. don't know where other people put their fuel regulators. not much room. used hard lines.

 

Very cool ... getting close

 

As I get older I check everything multiple times, so it takes longer. yes its very close.

 

I can't tell you how much time I spend looking for something I just put down and then find it way across the room ... how did it get over there?

 

I can relate to that.

 

Same here. Usually it's cause my wife moves it while I'm in the middle of a project. Come home from work or on a day off and try to pick up where I left off and spend 2 or 3 hours looking for tool/materials to find it in a box or tub she's moved somewhere else across the house or into the garage under a pile of her empty Amazon boxes. And she wonders why I'm less willing to do any honey do's now that when we first got married.

I'm to the point where I flat out refuse to spend more time looking for a tool than it takes to do the job, especially when it's not where I put it the day before

 

mine is all self-inflicted

 

Had to take 2 steps back in order to go one step forward. had to pull heads after doing a leak down test. made a plate to block off chambers with head off. lapped valves until they were .5% to 1% leakage. Now I have a method to check valve leakage. heads are back on, leak down test results are good now. Also made plates to seal water ports with heads on, so water system could be tested for leaks without installing intake manifold. good leak down results and no water leaks. can move forward now and assemble the rest of the engine. very tempted to get a sonic tester to test intake wall thickness. but that will be for a different intake manifold. going to mock up a port out of card board or something to see how much entrance taper is needed before grinding on another intake manifold.

 

purchased a sonic tester. this is a test intake. all measurements are .000 inches.
second photo shows stock port on left and right port that is ported to 1.5" tall. ported runner flows 225 cfm with clay entrance.
third photo shows stock port side wall thickness about an inch in on port #2 where the water jacket is in between the ports.
forth photo is showing the side wall thickness port #7 where the water jacket is in between the ports.
5th photo shows top wall thickness for end port. A little thinner.
6th photo shows outside wall thickness of end ports.
last photo shows side wall thickness for port #3 and #6 entrance.
hope this helps anyone that want to port intake.

 

A little update. entrance is now 1.7 high. runners 2 and 7 taper from 1.2 to 1.1, because of water jacket.
could rise the height to 1.5". there is room for that. My instinct are telling me this manifold is done. 215cfm. did port another manifolds runner to 1.5" main runner, it flowed 225cfm. 1.5 starts getting into top plate bolt holes. would need to use sealer. most likely 225cfm is the max that I can get.

 

2 steps backwards to get one step forward. I screwed up the head bolt sealant, had seepage. leak down test on cylinders wasn't good. made a plate for testing valve leakage, lapped valve better. no more water leaks and leak down tests on cylinders are now good. this is why I test for leaks.
really like sonic tester for checking wall thickness of intake manifold.
Installed intake with 1.4x1.1 main runners with .5 rod welded on entrance, flows 215cfm. could have raised and widen the runners to 1.5 x1.125 to get to +/- 230cfm.I wasn't comfortable with making walls that thin. the truth is, the 4 inner runners are easier to get to flow than the outer 4 runner. had to make outer entrances wider and or higher to match inter runners flow numbers. May do another all-out intake manifold at some point, now that I have a better idea of the wall thicknesses. as the ports get bigger the efficiency seems to goes down.
a rough way of estimating cfm per runner size with no round rod welded to entrance and rounding and tapering entrance as much as possible. is to multiply the CSA by 126. 1.4x1.1=1.54x126=194cfm 1.5x1.125=1.6875x126=212cfm. adding rod to entrance will add about 15 cfm, depending on size of runner and location of runner. I think 230cfm is the maximum with rod welded to entrance, because there isn't any more room. I'm sure someone with more experience could get more. I'm just a guy in a garage.
I'm fine with 215 cfm. considering the stock manifold flows from 148cfm to around 160 cfm depending on runner. runners are a little rough and inconsistence size and shape. 4 different types of entrances.
seems like I have to do things multiple time. must be how I learn.

 

its alive!
of course, I missed some things. hooking up power to fan relay, tach wire not hooked up. no big deal. I'm not sure I wired the 3 wire O2 sensor correctly or if I used correct O2 sensor, wants to die once it's warned up. no fuel leaks, no water leaks, no oil leaks. needs to be timed. going to check for vacuum leaks also. just got it running.
exhaust sounds good, but way to loud for me. dynomax super turbos. fix this last.
For people that want to do max porting on stock crossfire intake manifold. used $100 sonic test to check wall thickness. wall thickness varies. 230cfm is possible if you're comfortable with some of the wall thickness being as thin as .0625. I'm not. the only way I would do it is if the 2-water jacket between 4 of the runners are welded up. that's for another day. If renegade manifold comes back, then there's no point in doing it.

 

got it timed. got it to idle by turning the balancer screws on TB's. not sure if that's the right way to do it. can check tb balance now. Need to learn how to check throttle position sensor. revs up with no hesitation. can dig out my exhaust analyzer to check fuel ratio. have enough vacuum for power brakes. Idle is good, slightly higher than stock. I'm not done messing with it yet. time to quiet down exhaust now. I'm sure a lot of people would be fine with exhaust. I could get a ticket for loud exhaust here.
I would test drive it, but I live in NW and it rains a lot this time of year. rain/snow mix right now. would just spin the wheels. Need to fix exhaust anyways.

 

Over the years, I've tried just about every muffler for the C4 looking for one that is quiet and flows.

The Super Turbo has two open tailpipes but only really flows out of one of them.
The other sits in a camber with a wall in front of it ... just adds to the noise.
You can plug that one without hurting performance.
It will reduce the sound but probably not enough for you ... maybe just for a test drive?

I failed an emission test once because the kid put the probe in the "dead end" tailpipe and there wasn't enough flow to register on the machine.
You can imagine a little arguing happened and he retested it using the other tailpipe

 

thanks, I'll try plugging one. Going to use bore scope to look inside muffler. cheap bore scope is turning out to be one of the handiest tools. If this doesn't work, I'll try putting on a resonator.

 

haven't taken off muffler to check input side, that's a unknown at this point. this is what bore scope showed. 3" input and 2- 2.5" output. loud

 

Seeing the stock type rear Y-Pipe in your earlier picture, I assumed you where talking about the old Dynomax direct fit SuperTurbo's for the C4.

That's what my pictures show.

If you are using the generic three inch center in two pipes out, whole different animal ... I can believe it's loud

Interesting to see what the inside looks like.

 

I'm guessing this is what you will find when you look in the single inlet.
They wouldn't just flow through the perforations, has to be open paths through the pipes.
It's really just four GlassPack mufflers, not really a turbo design ... if true.



The Mass flowing into the muffler has to match the Mass coming out (conservation of Mass theory).
But the hot exhaust gas is going to lose a lot of temperature going through the muffler, so the Volume (cfm) going in is more than the Volume (cfm) coming out.
If it looks like my drawing, pretty sure you can plug one of these outlets and not hurt the overall flow through the muffler ... just reduce the noise.

Be interesting to see ....

 

Yes, I used stock y pipes. did enlarge y for 3.5 pipe. front Y is 2.5" OD with a smaller pipe inside the bigger pipe at the bends. could replace bends with mandrel bend elbows. rear Y is 2.25 OD. should go with 2.5" od. didn't think my engine would produce enough hp to need bigger pipes. I did use 3.5" center pipe and a high flow cat. the plan was to check exhaust for back pressure and modify pipes if necessary. I did make some inserts for mufflers 2.5 outlets. round perf tubes with packing around them. It helped but sounds a little odd at idle. it quiets down as it revs up, weird. I couldn't find direct fit dynomax mufflers. only could find walker. I'll check exhaust back pressure and if needed, make exhaust bigger. By the way these 3"muffler flow 700 cfm, way more than needed. maybe with some Y pipe resonators and muffler inserts it will be quiet enough. learn as I go.

 

I'll try that next.