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Modified l28et manifold


wax

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Thanks for that

I didnt do a measure. I more looked at it and decided what i thought it was close to

For the end one its not real an exact sicence but it looks close to 4 litres

I ended up using 4mm plate for the sides. Yes my plan is to try and keep the orginal throttle at all costs. if i cant do that then i will go for drive by wire so there is nothing hanging from the engine

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Nothing more to report so far

I have been busy getting my block hot tanked and getting that ready for the rebuild.

My main thing now is just getting it welded up and then sand blastered

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You had mentioned getting it sandblasted for a textured/rough look. I wanted something similar on a manifold I had planned to use on my turbo engine last summer. I partially shaved the intake and then took it to a sandblaster. I found that the sandblasting did not give much of the textured look I was looking for. If you sandblast the entire intake you will definitely see the difference between the original casting texture, sanded spots, your aluminum plate, etc. (as I did) The best thing to do it just get it all to a similar texture by hand sanding then maybe sandblast.

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yeah your right,

If you have a look at the manifold you can see where i have already started to do that with a catdrige wheel.

When its all welded up i will go over the whole thing and get that smooth finish on it. Then go and blast it then.

We have a sand blaster down the road from me i think he uses gravel as a medium ( haha) ,it should make for a nice rough finish like i am after.

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"Black Magic" the black slag/aluminum oxide blasting grit makes for a pretty agressive finish. Monitor blasting pressure and distance and you can get quite a range of finishes. You can even overwhelm the stock as-cast and massage it. Afterwords, you might consider shotpeening at a lower pressure to 'knock over the high sharp edges' from the more agressive media for a more muted satin look.

 

Rough becomes hard to keep clean, so maybe straight shotpeening to texture everything so it's somewhat 'wipeable'...

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I Bolted my intake manifold up to just make sure the clearance would be right

Its going to come through just perfect.

When i unbolted the carbs and threw them over my shoulder there was so much more room.

Will actually be easy to work on this thing with out those pesky old fuel hit and miss parts on it

No comments about the engine bay please , i know its a mess and i will get onto it after i have the parts all made up. I just done want to do it up and then have to work on it and scatch it all up

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About an inch out from the shorter section. Just waiting for the throttle body to turn up so i can put it on there and start to weld the manifold all up.

Then its the fuel rail and regulator and its close to finished.

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Equal length will help off boost response and.........make more power at low rpms which has the side effect of causing the engine to output more exhaust velocity which has the side effect of reducing boost lag.

 

Driveability makes driving more fun and much less like a chore.

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Yeah i agree with you. I just have seen some people disagree with it or think its not worth the hassle. To me its no hassle. Just finshed the merge collectors will go and pick some more pipe up today, with luck i may have the manifold close to finished next week.

 

 

I'm normally one to disagree with it but only on road race cars where I have plenty of A/B comparison experience.

 

Off boost response in road race environment is pretty much a non-issue since most engines never come down in rpms outside of where they make good power.

 

Another down side to longer runners is more piping that will be getting red/white hot under long pulls which means more surface area with which to radiate heat under the hood. (really only an issue when under boost and you're moving anyway so airflow helps).

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I'm normally one to disagree with it but only on road race cars where I have plenty of A/B comparison experience.

 

Off boost response in road race environment is pretty much a non-issue since most engines never come down in rpms outside of where they make good power.

 

Another down side to longer runners is more piping that will be getting red/white hot under long pulls which means more surface area with which to radiate heat under the hood. (really only an issue when under boost and you're moving anyway so airflow helps).

 

So then why did almost all old pre turbo ban F-1 cars as well as newer design cars use long tube equal length headers? High RPM, High Power, is it F-1 vs Road race?

 

http://gurneyflap.com/engine.html

 

http://gurneyflap.com/hondav6turbo.html

 

http://gurneyflap.com/bmwturbof1engine.html

 

 

 

 

 

2ndpart4.jpg

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LOL...........Monzter......I was thinking about that setup in the back of my mind when I posted that and wondering if the m12/13 would show up on this thread.

 

It seems the designers at that time also did not agree with each other and you can see both schools of thought in the engines from other teams of that same time frame.

 

Neither school of thought is "wrong".

 

On the Tag Porsche formula one engine pic below, the tubes might be close to equal length (kind of hard not to be with turbo centrally located) but they surely aren't long or "tuned" like the BMW ones in that the tubes are easily half as long as the bmw tubes and I'm positive that the rev limits are similar between the BMW engine and it's competitor engines shown below.

 

This is exactly what I was referencing when I made that statement about short length tubes.

 

DSCN4175b.jpg

 

The Renault turbo formula one engine.

 

DSC03763.jpg

 

The honda turbo formula one engine.

 

DSC03984.jpg

 

I can't find a good pic of the honda header but, from what you can see here, this header is even less ornate than the others.

 

I'm normally one to disagree with it but only on road race cars where I have plenty of A/B comparison experience.

 

 

The part "but only on road race cars where I have plenty A/B comparison experience" refereneces IMSA GTO cars since I did state "where I have plenty of A/B comparision experience".

 

The experience referenced was this porsche 935 in 1986-1988.

 

Here's a cool history on the car.

 

http://www.911handbook.com/articles/article_pwgarretson935.html

 

Funny thing about that car......I was at a u-pull junkyard in daytona 17 years after the last time I saw the car and the cell rang with somebody on the other end asking questions on that car and the later 944gtr which was purchased by the same buyer.

 

I could hear sports cars racing at daytona speedway a few miles away and immediately realized that the reward of free entry into a cool event (rennsport II) hung in the balance of my next few words.

 

I said "I can much better answer your questions in person..........if you can get me in." "I'm only 10 minutes away".

 

20 minutes later, I was answering questions on the 935 and this GTO 944GTR.

 

The mad scientist looking gesturing guy is Dave Clemm or "Mr. Fabcar".

 

His concentration is total and nothing kept him from being sidetracked.

 

I just stayed out his way.

 

944gtr1.jpg

 

The 944GTR used the long tube philosophy while the 935 used horrible looking pipes that made big power.

 

An hour later, I was kneeling and sighting down the side of a very dented up old 356 coupe and saw a pair of legs in my peripheral vision come up and said to whoever it was (without looking) "man, did this thing just come out of a barn?" as I stood and turned to address the person standing there.

 

He said "A chicken coop!.....It came out of a chicken coop!"

 

It was Seinfeld and I almost couldn't control myself from laughing because he said it just like he would on his show when making a point.

 

I snapped a pic as he got into the car next to it which is porsche branded car #1.

 

The dented car next to it also has a roof rack with a spare tire on it.

 

jerry.jpg

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I honestly don't know what is better now.

 

The 944GTR has the long tubes.

 

It made 600hp out of 2.5 liters in 1987 for hours on end though IMSA was already working toward sanctioning out turbo cars at that point.

 

Al Holbert's death put an end to anything more than privateer development.

 

944gtr3.jpg

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The Pre Ban F1 Turbo Cars were making 1500 to 1785hp (that anybody knew) from 1.5 Liters.

 

Which was Benneton F1 back in the early 80's? BMW? You know the lead engineer for that team is a member here...right?

 

Muahahahahaha!

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Yes, I believe benetton still had bmw power when Teo Fabi drove that beast in 1986.

 

I remember seeing him get the lead of a F1 race for the first time and the engine grenading half a lap later.

 

Early 80s was Nelson Piquet in a BMW powered car but can't remember if it was a Brabham or tyrrell.

 

The f1 guys should have seen it coming when this car came out in 1977 with an earlier version of that powerplant.

 

bmw320t78.jpg

 

It's for sale.

 

http://www.johnstarkeycars.com/pages/for_sale/BMW320T.html

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  • 4 months later...

I enjoyed reading this thread today and was wondering if there was any updates on this? I am looking for a good intake match for my ported p90 head. I will do some calculations to see what flow numbers I need tp make the HP level I am aiming for. I am a newb when it comes to putting flow numbers, cam lift and exhaust flow numbers together to see what makes sense.

 

I am thinking right now, ported 75 non egr intake will be my best bet. My setup is a 3.0 short block and a very well prepped p90 head.

 

Thanks for any updates.

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