Custom Intake- How much can the stock ECU handle?

[Challenger]

Well Ive been doing research for my turbo build this summer and am starting to consider experimenting with the stock turbo manifold, or making my own from the stock flange. My question is how much can you modify the stock manifold without loosing power. From what Ive read doesnt matter if the new manifold flows better, with an adequate ecu you wont see an improvement. How much have you all been able to modify your intakes or run completely custom manifolds with the stock ecu.

 

This will be going on a f54 p90 turbo motor stock efi, stock turbo, ~12 psi, intercooled and custom downpipe if that helps.

 

Thanks

[Challenger]

 

http://forums.hybridz.org/showthread.php?t=132014

 

This is kind of what I was considering. Would using the stock runners slightly bored out with a plenum like MONZTERS work with the stock turbo ecu? Would it work but not be worth the minute gains?

 

I was also looking into Justin Olsons flanges. Maybe using his flange and similar runner and plenum dimensions so it remains closer to the stock but with flow gains. (custom manifold)

 

Thanks

[MONZTER]

Here are some more pics of the work in progress.

 

The engine is a stock 240z bottom end that revs very quickly to 8000, With 10.5 Compression ratio and a MSA 2003 cam it made 210hp at the rear wheels. I sent the plenum to Rebello when he was doing the port work on my turbo head. He tested it and said it should flow enough for 450hp with the GT30 I was planning on using. Dave said he has seen NA cars with heavily ported stock plenums like this making 300 + HP.

 

If you compared the stock insides to what I was able to remove below, I don’t see how it could not help

 

BTW I also changed the flange to a 6 bolt set-up for the earlier heads as well as injector bosses in the runners. You can also see how the TB flange has been angled to help flow into the number 1 runner as well as provide a straight shot to the core support for straight 3" tubing.

 

Jeff

 

 

 

 

[Challenger]

Thanks for the pictures and the pm. Really looks nice!

 

But would there be a possibility of this working with the stock ecu? Im sure you could get alot of benefit out of it with a standalone as you are doing, but would It be worth all the time and effort to make something similar and use with the stock fuel injection?

 

Thanks

[Challenger]

 

Well started working on mine. Was able to get about 10 bosses shaved off and I still have around 8 more to go.... Snapped a picture of the inside, to my shock it was quite clean, other than all the little dimples from the screw holes. If I have time tomorrow Im going to go ahead and shave off the other bosses, and maybe try to cut off the egr port. Anyone know of a good way to fill in large holes? Like the one at the back of the manifold in the picture. Ill hopefully get most of the holes welded up before I cut the manifold open. (how...)

[MONZTER]

The part you cant see is the problem. Mine had casting bumps right in the middle bottom of the runners where they attach to the plenum. Once you cut it in half and can see down the runners, you should be able to see how you can open up the runners to make a difference. I think the plenum is not really the problem, but the size of the runners.

[Challenger]

 

 

 

I got all the other bongs off and smoothed most of the plenum. But Im ending up with some large holes. Can this be welded up? Also there was a port on the middle right runner, from the inside I can only see a hole for where the sensor screwed in so I still need to carefully grind it down smooth. Also need to do some porting for my 60mm tb, but Ill do that once I get the plenum apart.

[Tony D]

Lumiweld and a propane torch...

Or heliarc, yeah they can be welded.

 

The bumps at the inlet of the runners are a frustration! I think this is where the EGR is introduced on some manifolds, but on my P82, I didn't have EGR, but STILL had the same bumps (just without holes in them!)

 

Probably says a lot about 'common runner cores for casting all manifolds' than anything else!

[Challenger]

Thanks Tony, I had seen some alumiloy commercials on TV, Ill have to look into it. Seems pretty easy.

 

Specifically for MONZTER, but anybody else that has ported the stock runners, what was the interior dimensions? From what I can feel and see from inside the plenum there arent any bumps and it is pretty smooth. So the only improvements I could make are opening them up alittle.

 

Also Monzter what did you use to cut open your manifold?

[MONZTER]

Hi Derek,

Mine was like Tony D said. It was a non egr manifold, but still had the bumps right in the inlet of the runners from the plenum, just no holes in them.

 

As far as my mods I did, I opened the up a bunch by removing the casting bumps mentioned above. I then blended the runners into the plenum making the entry as smooth as possible. I opened up the runners the max possible but not fully concentric. What I did was make the runners as straight as possible to the port as I could. This means the runner are much thinner on the inside of the bend radius, imagine the shape looks the same from the outside, but a straighter line for the inside. Makes sence??

 

I used a 14" band saw to cut mine up. Put it on the table and cut it open.

 

I TIG welded it back together.

[Challenger]

Yeah makes sense. Thanks. Did you use the ~6 inch long carbide bits to get to the middle of the runner?

 

Im hoping to try and use the band saw at my high school to cut it open, and then Ill try to get some alumalloy or similar to patch the holes.

 

Got a few more questions.. You mentioned rotating the Tb opening. Do you think its worth the hassle to do? I really dont have access to many tools other then an angle grinder and a heavy duty dremel. Would I see much improvement over the stock position? (with 60mm 240sx Tb pictured)?

 

Wish I had a tig welder.

 

Thanks

[MONZTER]

I dont use the 6" long bits. I buy standard length and then use an extension. This way I have both lengths for the price of one. This is what the bit looks like. It is clog free for aluminum. I would also use cutting wax to help keep it from clogging.

 

 

I rotated the TB, but it was a lot of work filling in the radius to get it to flow into the first runner. If you dont have a tig, and dont know how to build aluminum up with a tig, I would say dont do it.

[Challenger]

 

Well I used a cop saw to cut the bisecting lines (first pictures), and then attached metal stripping to give me a strait line to cut it with a dremel. Got the bottom cut nicely then went to do the top and only got a few mm down, ran out of cutting wheels. Had to finish it with a bare hack saw blade.

 

When I got it apart I was amazed to see it wasnt the rough... no casting bumps at the base of the runners or anything. The only thing I will be able to do is straiten the ports like MONZTER said.

 

Im going to get it sandblasted tomorrow at school, and will then be able to see what Im working with...

 

Now I have to do homework. Hopefully Ill be able to work on this over the weekend.

 

Thanks for all the help.

[Challenger]

Runner 1

Runner 2

Runner 3

Runner 4

Runner 5

Runner 6

Inside Plenum

 

Like I stated earlier, Im not sure where I should remove material to make this flow better. Other then removing the bumps on the inside of the plenum, filling in the egr ports, and porting the tb opening for my 60mm, and filling/smoothing opening on runner 4 Im not sure what would provide the best improvement.

 

From the pictures of MONZTER's plenum it seems that you have shaved down some of the material the seperates each runner. Should I look at doing that?

 

Ive also looked at rotating the Tb just slightly outwards. I think it wouldnt be to much work while the plenum is apart to do this. It looks like it would really help runners 1 and 2.

 

Thanks

[Challenger]

More pictures..

 

Vertical butterfly- Seems to funnel more air into the first 3 runners under lower throttle. Would this help?

 

Horizontal (stock)

[col]

I'm no expert but I would think the stock arrangement would be best.

Even at half throttle you will be affecting which runner gets air , if you twist the butterfly.

[Mayolives]

Derek,

This is a very interesting thread. You are doing a nice job with showing the procedure of improving flow of the basic intake design. Please show us some pictures of the Lumiweld results. Keep up the good work. Your posts are excellent examples of why Hybridz is the "tits."

[Challenger]

Havent been able to do any of the welding yet and probably wont get to it for the next few weeks. Im moving into finals weeks so I should be doing homework instead of being on HBZ.... But Ill get some pictures once I start working on it.

 

Also anyone been able to do porting with a dremel? I dont have an air compressor or tools so I cant get the bit MONZTER told me about.

 

BTW, you get those fender vents mounted yet?

[Challenger]

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=150254640559&ssPageName=MERC_VIC_RCRX_Pr4_PcY_BIN_IT&refitem=150252259875&itemcount=4&refwidgetloc=closed_view_item&usedrule1=CrossSell_LogicX&refwidgettype=cross_promot_widget&_trksid=p284.m183&_trkparms=algo%3DCRX%26its%3DS%252BI%26itu%3DUCI%252BSI%26otn%3D4

 

Went ahead and got some welding rod. Hopefully Ill get it soon so I can experiment with it. Ill be sure to keep this updated.

[Challenger]

http://www.chickys.com/ultrafuse.html

 

Heres some more info on the stuff.