Latest Project - Headers

[911nut]

Another observation.
You may consider dropping the height of the box approximately one inch so that there's room to install onto the long studs used for thick flanges. As prototyped, there would be no room to work spacers onto long studs.

[RarlyL8]

This "design" is very preliminary to see what the obstacles would be working with a real header rather than just on paper. What I will do next is remove the Cheerios exchanger, replicate it in poster board and install it on the exchanger on my car. That is where the final design tweeks will be done. I'll then take the header off my car, install the prototype exchanger and re-install the assembly on the car which will expose any installation issues.
I'm sure it won't be as easy as headers alone but I'll make it as painless as possible.

[jonesb930]

Brian,

Will you be using 321 or 304 Cheerios boxes?

Bill

[RarlyL8]

Ha, that's a good question. 321 is overkill for a heat exchanger but I'll have to take a look at bulk cost for flat stock as that is what we make the muffler bodies out of.

[JFairman]

The heat exchanger boxes probably don't have to be as tall and as close to the exhaust port flanges as that cardboard mockup is but boxes that big will definately make serious interior heat even in northern Alaska during January.

Too bad the most attractive part of the headers is completely covered up with that heat exchanger box design.

Also if you use 12mm wrench size copper locking exhaust nuts on the exhaust port studs then a long offset 12mm box end wrench should get at them from the sides easily.
You can also take a Sears or other inexpensive 12mm long handle box end wrench and heat it red hot and put a bend in so you can get the box end in there from the sides and tighten/loosen them.

I have a couple bent handle 12mm box end wrenches, and a 12mm Sears offset box wrench that I use for removeing/replaceing my B&B headers with heat, along with the pos B&B wrench with a welded on chinese 12mm box end on the end that bends easily when using it.

[RarlyL8]

Funny you mention that Jay, I stopped in my hardware supplier today and had him price me 8mm copper clad nuts as an option to include with each set of headers. A 12 or 13mm box end gets in there pretty easy.

I agree that I hate to cover these headers up but they are under the car anyway so rarely seen.

The Cheerios heat exchangers represent the max area I can cover up. The final product will be a compromise and a lot of area will be lost. I have some ideas on how to increase surface area inside the exchanger so they can be reduced in size. I'll be back on it this weekend.

[maximo]

i order mine next month ! remember

regards Max

[911nut]

Originally Posted by RarlyL8

A 12 or 13mm box end gets in there pretty easy.

No, it won't.
I've got 993 h/e's on my car. On the unit with the flipped flanges (r/h side) it's almost impossible to swing any kind of wrench on the rearmost stud. That's why if I ever take it off, I will not re-install it.
My advice is to make every effort to make those heat exchangers easy to get a wrench on. The best way to insure that is to be able to use a normal socket and a long extension in a straight shot.

[RarlyL8]

These aren't 993 exchangers. I designed the headers to install easy and they are identical on both banks. My plan is to retain that design I worked so hard at and not ruin it by blocking with heat exchangers. Not an easy task I admit ...

[mb911]

Originally Posted by RarlyL8

Ha, that's a good question. 321 is overkill for a heat exchanger but I'll have to take a look at bulk cost for flat stock as that is what we make the muffler bodies out of.

321 sheet and 304 sheet is about the same prices so it would be up to you

[RarlyL8]

Same price means 321. Good deal.

[WERK I]

WinRice made a nice observation I wasn't aware of until I reread this entire thread. These headers are equal length all the way up to the turbo flange. Nice!! Way to go Brian.

Plus the obligatory bump.

[zaidigonzo]

sent you an email Brian. Need a set of the headers to go with your exhaust I got earlier. Seems my 25 year old system is cracked and heater box had a hole in it. .....


such a steep slope.......

[RarlyL8]

The long awaited dyno run is now in the books and it looks like the homework has paid off.

The results have surpassed my expectations. There is more torque everywhere. The car drives like a 3.2 Carrera off boost and you can see it on the graph. (Graph is Headers vs Euro J-Pipe)

The dyno did not have a way to record boost so you have to take my word that it stayed the same. We watched it close on the VDO clock gage. I can add boost recording to my LM-1 and will do that later. Even if we do see a slight boost increase it has nothing to do with what you see on this graph pre-boost.

Important Note - I am going a little lean now with my rebuilt non-adjustable test mule WUR. AFR's went from mid-11s with the J-pipe to low to mid 12's with the headers.

[kenikh]

Wow. Wow. That's for real.

[JBL930]

So everything the same, turbo, boost level, airbox, cams etc.. Things like aircon, air injection blah blah... The ONLY thing being different being the headers? If so that is staggering! Genuinely amazed! Top stuff

[JFairman]

Originally Posted by JBL930

So everything the same, turbo, boost level, airbox, cams etc.. Things like aircon, air injection blah blah... The ONLY thing being different being the headers? If so that is staggering! Genuinely amazed! Top stuff

One litle thing is different according to the graph, it was 10 degrees cooler out but that wouldn't make much difference... maybe 1 or 2 horsepower if the intercooler wasn't heat soaked.

WUR's can make a difference.
If you put an adjustable one on there that has boost control pressure set lower than the one on there now not only does the control plunger raise a little higher in the fuel head uncovering more of the metering slits so more fuel gets injected, also the air flow metering plate opens a little farther at the same time so the turbo has an easier time sucking in air.. and it does, building a little more boost in the process.

[JBL930]

You can see the fueling is better, i guess the extra power is using the excess, but as Brian said it's getting lean at 5.5k.
It would have been great if the runs could have been done litterally back to back, no margin for error then.
Some timed 60-130 runs would also really show the difference. Even 30-90mph would be something to look at

[RarlyL8]

If you have been following my long winded thread you know I gave the engine a tune-up when it was out. New plugs, plug wires, rotor, cap and checked the fuel injector pattern.
I don't know how much power that would add but I'm still very happy.
My engine uses a K27-7200 turbocharger and SC cams. Heads are stock, boost is stock 0.75bar and intercooler is oversized 1/2 bay. No A/C. All runs are done in 4th gear using a 915 tranny.
I have dynoed my mule engine multiple times in all kinds of weather using the same dyno and find the power is +/- 5HP variation. We get the car on the machine with the oil temps right at 180* and do 2 quick pulls so there is little time for heat soak. I have found that sever heat soak can cause a 25HP loss in HP and a 500rpm additional turbo lag. That is HUGE. The second pull is always ~3HP lower than the first. We only did one pull today. I don't like mid-12's for AFR so did not wish to do another. Time to put on the adjustable WUR.


All things considered I think it is fair to say that these headers have added 25 ft/lb of torque and 30HP. The difference in driveability is wonderful. I have Carrera-like off boost manners and still get the hard hit at 3000rpm. This should be especially helpful to those running the K27-7006 or K27HF turbochargers.

[JFairman]

Thats really good because the general consensus is B&B headers only give around 5 to maybe 8 horsepower more than the stock euro exhaust and 1986 -'89 USA exhaust on a CIS motor, while weighing less.