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3point8 Performance
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Discussion Starter · #1 · (Edited)
A look at Hyundai's sh*t QC.

In case you don't know, my goal is to get the most from the 3.8 without shelling out big $$, but instead, to find ways to optimize what Hyundai gave us. I'm not trying to be cheap; if i just wanted to throw parts at this thing, my income would have no problem with that. What I enjoy is optimizing what other people have done. This has a nice benefit of allowing me to learn more about the platform and also to share that knowledge with you guys. A side effect is that i find ways that others can improve their own performance. So this thread is a precursor to my upcoming build thread.

I've organized another SFR event here in SoCal, so I am looking for anything and everything I can to improve my dyno numbers. At this point, I'm doing micro optimizations since I've done just about everything else. Once I have the final numbers, I'll do a full write up on my build in a consolidated post. For now, I just wanted to give you guys insight into the absolute garbage QC that hyundai produces.

Intake manifolds

You guys have seen my manifold thread i'm sure. I've been offering manifold porting for BK1 and BK2 3.8 (I do 2.0T as well) and I've seen almost 60 manifolds. This photo is of my manifold, and it's actually really clean compared to some of them i've seen.

Here are some other manifolds I've snapped pics of



BK1 manifolds are really bad. I had a BK2 manfiold not long ago with casting seams that protruded over a millimeter into the throttle body mouth. It's insane! I just recently released before/after dyno results of my stage 1 port package and all I'm doing there is cleaning up the rough castings and it made gains!

Heads - Intake ports

This is an image I took of the intake ports on my heads. This photo is the passenger side, but the driver side is no better. In a few of the ports, there was overcast that protruded into the path of the airflow. I was able to clean these up in just a few minutes with a rotary tool, so why couldn't hyundai do the same? I spent some time cleaning up the ports as the seams were pretty rough and there was some slag in a few of the ports, so I smoothed everything out. It made a noticeable difference in power on the butt dyno.

Heads - Exhaust ports



These are the exhaust ports on my heads. I took these photos using my borescope, so sorry for the bad quality. As you can see, there was not clean up done on the ports so there is a nice lip all the way around each port. In these photos you can see slag protruding into the path of the exhaust flow. Some areas were at least .25mm tall!


I spent about 20 minutes with some 100 grit sand paper and cleaned up all of the ports. Again, why couldn't hyundai do this? The walls of the port and divider were very rough, so I spent some time cleaning them up and smoothing them out. As with the intake ports, there were some ports with slag which caused bumps so I smoothed all of those out as well.

Exhaust
The exhaust manifolds were no better. They are stamped steel and get welded to the primary cat which is cast iron. The runners looked like they were cut with a band saw and had burrs on every single runner. It only took my a few minutes with a carbide bit on my rotary tool to clean them up.

The output of the cat I found on the driver side was not perfectly circular and was not a full 2.25" wide in some areas. I was able to clean it up with a large carbide bit and a die grinder. The passenger side had protrusions into the exhaust path due to 2 bolt placements. I did some measuring and cut them down a bit. This isn't necessary a QC issue, but instead a design problem.

The down pipes I found to be ridiculous as well.



The weld bead causes a reduction in the down pipe. On the one pictured here (passenger side) it's a 2mm difference. These are supposed to be 2.25" and as you can see on the digital calipers, this side was 2.17". The drive side down pipe was no better. I cleaned them up and now they're 2.25" as expected.



You might worry about the weld holding, but there is more than enough on both sides to keep it together.

In the future I plan to pull the heads and do a full port and polish and I'm betting there will be a lot of issues around the valve seats and probably slag in the coolant channels, so we'll see.

Conclusion
So, as you can see, hyundai needs to step up its game. I'm not sure if the 2.0T, sedan or new models also have these problems, but for us 3.8 guys, it's something to think about. I don't know what gains to expect from cleaning up all of these imperfections, and I have spent significant time doing so, but at least I have the satisfaction of knowing I've done so.
 
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Nice write up and good work man. I seem to recall a few years back some others that were porting & polishing the BK1 intake manifold did some flow tests and found air starvation to a couple of the cylinders - a quick cleanup of edges & smoothing out the intake plenum definitely helps bump up the power. More flow = more go.

Keep it up
 

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3point8 Performance
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Discussion Starter · #3 ·
yeah, the BK1 really shines with a ported manifold. I did one for a customer here in San Diego and he put down 306whp at the tune event. So far that's the highest numbers I've seen for a BK1 without cams.
 

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I'd add the transmission mount to the list. Pretty much everyone that has replaced it shows just how malleable it is or even downright breaking apart.
 

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My I play the Devil's Advocate here?
After 28 years in the Automotive Machine Shop industry I have had the opportunity to port many
items from various manufacturers and I have to say what I see in your pix is par for the course no
matter whose name badge it belongs to. Really have seen much worse from the big three domestics.
Just a full radius valve job (three angle valve jobs belong in the stone age ) improved flow on an
average of 10% Depending on the job, verified by my Superflow SF 600 flow bench. Some as little as
5%, some as much as 25%!!!!!!! This was just a valve job. All flow tests were conducted at 28" water.
I should add that the Full Radius Valve Job included bowl work as well.
A lot of racing classes I did work for, gasket matching and port work was prohibited.
There were some cases where the gasket match and cleanup did not flow as well as a good valve job.

Forgive me I seem to have gotten side tracked, l suppose my point was that you are doing the right
thing but all manufacturers have the same issues and anyone willing to go your route will wind up with
a better running machine. Also when you tear your heads down look into a full radius valve job, if your
machinist is not familiar with the concept find another one. Ideally your machinist will use Serdi or Sunnen
equipment or equivalent. I am willing to bet the exhaust side is horrible.....

Forgive the long post and do keep up the good work Titan, we could use more on here with your drive
and enthusiasm.

TJ
 

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shorttrack
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Titan is 100% correct , another items Hyundai overlooked is the lower manifold runners to the head port alignment ,the lower half manifold runners do not not fully line up with head's intake ports (viewed with a mini mag light or bore scope ).This can be fixed by installing rags in the ports that need cleaning up in the head with a dremel and the port that do not need cleaning up just tape those closed and carefully clean up till matched (use a long scribe to etch were clean up is needed with the lower manifold installed ).Clean very carefully as to not get trash into the intake port.
 

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Bill
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way, waay back when; a friend of mine had a brand new pinto wagon*. he swore that if he took it apart and put it back together torq'ing every bolt to engineer's spec, it would be as good as a merc. just to reinforce Mr Destine's comments. bean counters will almost always overcome the engineers.

* the wagon seemed to overcome many of the car's infamous failings.
 

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3point8 Performance
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Discussion Starter · #8 ·
My I play the Devil's Advocate here?
After 28 years in the Automotive Machine Shop industry I have had the opportunity to port many
items from various manufacturers and I have to say what I see in your pix is par for the course no
matter whose name badge it belongs to. Really have seen much worse from the big three domestics.
Just a full radius valve job (three angle valve jobs belong in the stone age ) improved flow on an
average of 10% Depending on the job, verified by my Superflow SF 600 flow bench. Some as little as
5%, some as much as 25%!!!!!!! This was just a valve job. All flow tests were conducted at 28" water.
I should add that the Full Radius Valve Job included bowl work as well.
A lot of racing classes I did work for, gasket matching and port work was prohibited.
There were some cases where the gasket match and cleanup did not flow as well as a good valve job.

Forgive me I seem to have gotten side tracked, l suppose my point was that you are doing the right
thing but all manufacturers have the same issues and anyone willing to go your route will wind up with
a better running machine. Also when you tear your heads down look into a full radius valve job, if your
machinist is not familiar with the concept find another one. Ideally your machinist will use Serdi or Sunnen
equipment or equivalent. I am willing to bet the exhaust side is horrible.....

Forgive the long post and do keep up the good work Titan, we could use more on here with your drive
and enthusiasm.

TJ
True, I've torn in to a few motors and each have their own flaws. The SRT4 doesn't suffer from burrs, but a good example is the transition from the exhaust manifold to the O2 housing, it isn't cast to exactly match, and the o2 housing to the down pipe doesn't quite match up either. Even aftermarket parts like some of the edelbrock intake manifolds need a bit of work.

I'll be doing the head porting myself since there is no one around here capable (or willing) to port heads.

It's the little things that add up and improve reliability and longevity, so worth it to me in the end (especially now that I'm done!!).

Titan is 100% correct , another items Hyundai overlooked is the lower manifold runners to the head port alignment ,the lower half manifold runners do not not fully line up with head's intake ports (viewed with a mini mag light or bore scope ).This can be fixed by installing rags in the ports that need cleaning up in the head with a dremel and the port that do not need cleaning up just tape those closed and carefully clean up till matched (use a long scribe to etch were clean up is needed with the lower manifold installed ).Clean very carefully as to not get trash into the intake port.
Thankfully mine were good enough once i cleaned up the over cast, but I wouldn't be surprised if many others suffer from misaligned ports. But, doing these tasks ourselves is what gives us the advantage.

way, waay back when; a friend of mine had a brand new pinto wagon*. he swore that if he took it apart and put it back together torq'ing every bolt to engineer's spec, it would be as good as a merc. just to reinforce Mr Destine's comments. bean counters will almost always overcome the engineers.

* the wagon seemed to overcome many of the car's infamous failings.
True, the bean counters do tend to screw things up for us enthusiasts. Then again, if they weren't there and the engineers were left unchecked, no one could afford the cars :D

In a lot of cases, just reassembling things with care can net gains. When the line workers and mechanics are slapping your car together, they don't care much about perfection. My exhaust for example, the test pipes I installed originally were not lined up with the CBE so essentially I had a self inflicted obstruction in the exhaust path. I spent some time correcting it. Like shorttrack mentioned, the lower manifold can move around, so the alignment to the intake ports on the heads can be off, so spending the time to get it as close as possible can be beneficial. Lots of little things.
 

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I rememember dealing with this stuff building up cars back in the 70's. As concerned as manufactures are about weight,power,emmissions, and mileage im suprised this is still a issue with modern manufacturing techniques. I guess the diffrence between mass market vehicles and nich market vehicles is one is built up to a standard and the other, down to a price.
 

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Titan, i like your idea though, make the car the best it can be within the origional design peramiters. No disrespect to those who choose to go all out on builds, I still love reading about them, but my personal thought is im not intrested in making my coupe into somthing it was never intended to be,just intrested in making it the best it was designed to be.
 

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shorttrack
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Titan something you might want to look at is ducting a Allstar Performance Inline Duct Blower to the underside of the upper manifold and also routed in the V of the engine.In the V-area of the block you will be cooling the lower intake manifold and injectors/fuel lines .The Datsun 280ZX had such a system because the exhaust was directly under the intake manifold ,heat shielding was not enough.50 degrees temp drop is recorded when road racers use these blowers on braking systems.I just ordered mine from summit racing $23.99 plus shipping.I will use it on a switch while stopped and keep the my water/meth switched to distilled water while running at speed ,W/M set to come on at above 3,000 RPM's.The blower would be turned off during driving but will still produce air flow to the manifold from out side of the engine bay , my left side fog light plastic fake screen I carefully cut out and replace with true screening,same as my CAI on the passenger side.There is 2 CFM's listed but may be more ,170 CFM and 240 CFM.
 
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3point8 Performance
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Discussion Starter · #12 ·
That's an interesting idea. I was considering something like that. I'm also contemplating deleting the coolant line running through the lower manifold. Glen says he thinks it's just for warm up like the TB coolant lines, but no one knows for sure and I haven't been able to find any answers. But, even if I did delete it, not sure if it would improve anything. A fan could though.
 

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shorttrack
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Titan, i like your idea though, make the car the best it can be within the origional design peramiters. No disrespect to those who choose to go all out on builds, I still love reading about them, but my personal thought is im not intrested in making my coupe into somthing it was never intended to be,just intrested in making it the best it was designed to be.
Problem is that the Gen Coupe has too many design flaws.Those flaws are caused by refined items not being implemented because of bean counters or trying to please the general population not the true general population of car nuts that can build within a budget and get these cars to really run outside of their class.It is good to work around OEM short comings and make My Gen stick it to higher end cars .>:D
 

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shorttrack
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That's an interesting idea. I was considering something like that. I'm also contemplating deleting the coolant line running through the lower manifold. Glen says he thinks it's just for warm up like the TB coolant lines, but no one knows for sure and I haven't been able to find any answers. But, even if I did delete it, not sure if it would improve anything. A fan could though.
I built Datsun L28 motors in the 1980's and the injector/manifold blower fan was the best thing around because it worked .Look it up .I should have mine end of the week and installed the week after .
 
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