https://www.rx7club.com/showthread.php?t=395735

I was amazed at how nicely everything was when i took it off the car. No issues with any welds. No leaks around any welds. The divider in the runners held up beautifully and didn't errode any.

I'll put up more detailed pictures of it tomorrow once i get more batteries for my camera.

That is straight off the car...no prettying it up at all. a good glass bead and polish...it'd be shinny as new.

john

 

Looks pretty good - did you have to modify it at all before using it originally??

 

I added the Tial wastegate flange and had the flanges flattened.

I didn't have to re-drill the turbo stud holes, but needed to open up the turbo holes a bit. they weren't perfectly aligned.

john

 

is that the s s autochrome piece?

 

Looking good

 

yes, ss autochrome.

I didn't get a chance to get more pics tonight....

john

 

teeter - what do you mean the manifold has been "fixed" ?

also how many miles on it? was it daily driven on? any track time? and when did you purchase it?

thanks

 

Fixed: I cut off the hks wastegate flange that is what everyone complains about not being aligned...and I had a tial flange Tig welded on. I also had the flanges flattened...ground flat. I drilled out the holes in the turbo housing to get it to fit on the manifold because the studs were angled out due to the warped flange. When I took the turbo off...the studs are straight up and down now that the thing is fully heat cycled...while being bolted down. So, I am going to flatten the flanges again before I sell it to just make sure its good for the next owner.

I didn't reinforce the welds...my 30 year veteran welder said they were fine and dumping more metal on them wouldn't make them any stronger.

Yes, it was daily driven for 10k miles in the last year. A few long trips...lots of back country roads...never tracked...but I'm not exactly a "gentle" driver...but it was only running 9 psi and I never went past that because I never upgraded the injectors...stock injectors are good for about 300 hp...so thats all I pushed through the engine...but the EGTs won't be TOO much higher with higher boost and the pressure might go up 10-15 psi...but its pretty minor...unless you start running race gas and pushing 25+ psi...then the inefficencies of the rotary will make the EGTs climb like crazy...and anything short of 321 or cast manifold will not hold long term...imho.

I bought it in Jan 2004.

John

 

where are all the haters now?

 

I've been saying this the entire time...I haven't seen any evidence that they crack...just lots of forum parots saying they do. Mine is fine as well. Just about every person spouting on and on about how poor the quality is and how it will break in 2 seconds hasn't even seen one in person...and those that have, never actually used them

 

yah...no kidding...

so why am I having such a hard time selling the kit for REALLY reasonable pricing...

The turbo is perfect daily driver turbo...imho...T04s with .84 hot side, 360 degree thrust bearing, water cooled, v-band.
The wastegate is the BEST...tial 46mm and is tied back in.
good manifold and decent downpipe
heat blanket...greddy pullies

the works for 1800. This is equivalent to a lot of 3500 dollar kits...for half the cost...

John

 

Its not all about egt's. Its also about BTU's which is the amount or volume of heat. BTU's (heat not temperature) go up dramatically with power. Start pushing 450-500rwhp thru it and you'll wish it was made of THICK 304ss or some 321ss.

300hp doesnt generate much heat

 

but if the exhaust gas velocity and mass increases dramatically as you increase power...thus it will carry away a lot more heat. the exhaust doesn't stick around to transfer the additional BTU generated by more fuel being burt to the manifold...

the EGTs are 1600-1800 on a good tune whether you're running 300hp or 400hp...and yes there is more exhaust flow and thus more BTUs...but the exhaust flow is proportionally faster...so the time its in the manifold goes down...thus heat transfer to the manifold is relatively constant.

Those fluid flow and heat transfer classes in my chemical engineering degree just keep coming in handy

john

 

Thats like saying your cooling system doesnt transfer more heat at 6000rpms as it does with 1000rpms, I guess there is no point in having much higher flow at wot than at idle. There is a limit at some point because as the heated item gets hotter and hotter and becomes closer and closer to the temperature of the media the btu transfer will slow down. Thats not going to be the case in this situation.

Another example would be like saying if you wave a huge 2500 degree torch back and forth up and down your exhaust manifold it wont transfer more btu's than a small tiny 2500 degree soldering torch. Its just not happening like that man.

Whats going to happen is that the lager combustion with the higher btu's will transfer more btu's into the manifold much faster. You stop on the gas for 15 seconds and the higher hp car will transfer more btu's into the manifold at a much faster rate than the lower hp car. If you kept your foot on the gas indefinatly they might both eventually reach the same btu transfer level however the smaller hp engine will take much longer to get to that level. When your only running wot for short periods of time this makes a BIG difference.

Sure a lot of btu's get carried out of the exhaust, but a LOT of it gets ratained in the turbo manifold which is why the material of a dp isnt as important as a turbo manifold.

What school did you go too?

Stephen

 

i think i have pics somewhere of my ebay manifold, it was the OBX manny, and had the normal square holed t4 flange, not the half crescent holes. anyway mine was almost cracked in half. two large cracks going almost all the way around one of the runners. i have a picture of it next to the OBX plaque that says "high quality exhaust parts" or something. i'm glad you had good luck with yours. i've got the HKS cast manifold now and i love it.

 

UW

the coolant system is a completely different system. It is no where near saturated with heat...and gas flow heat transfer and liquid heat transfer are completely different animals.

Your torch example is not applicable either. Apple and oranges from the gas to solid heat transfer of a high speed gas flow through an exhaust manifold.

the exhaust manifold will be very close to the temp(relatively consistent) of the exhaust gases going through it minus how fast it can radiate heat to the outside world(consistent based on the temp of the manifold).

If you took an external temp reading on a exhaust manifold making 300 hp...and one making 400 hp...the temp difference is going to be in the 100-200 degree range. Not signifigant. I'm not saying it won't be hotter at all...but its not going to be like 1000 degrees for 300 hp and like 2000 degrees for 400 hp.

Look at it this way...if your theory made sense...a top fuel dragsters headers would melt instantly...because they make TONS of hp. They don't because the gases coming out of them reach a plateu and then the gases are flowing through so fast that they don't have the time to transfer more heat.

the temp of the exhaust coming out of a 300hp and 400hp tail pipe...much different. Thats where all your heat is going. If you think it all gets transfered to the exhaust manifold...then the tail pipe exhaust temp would be the same at 300 as 400.

Do you have a car with an EGT guage? I do...

john

 

Still here.

Amazingly, that is not the same manifold I saw.
There's more than one SS turbo manifold available from these idiots.


-Ted

 

well, thats the one that i have!

 

I had one that cracked, right near the turbo-manifold flange, where the runners split. I also bought the FC one and it is NICE, honestly it is heavy and thick as ****. Also whatever metal they use ate up some top of the line drill bits very quickly.

 

REted is correct, there actually are more than one of these manifolds. I've had all 3. There's the OBX which has a 3 part runner and a 2 part runner and actually has OBX stamped on it. There are also 2 different ones from ssautochrome that look the same but one weighs a noticable amount more and obviously has thicker flanges. They are about 50% thicker than the other. I can't say about the gauge of the wall but it did seem thicker too.

 

More pics on the forsale link.

you got any idea how heavy the "good" one was? I could weigh this one...it feels pretty dang heavy to me...

John

 

.

 

i want to see someone seriously abuse one of these... aka take the car on a road course and do a 20min session... see if it cracks. If it doesnt... well i still wont buy one but it shows that they are kinda strong. Has anyone cut one of the tubes in half and mesure the wall thickness and also cut thru one of the welds and look at the penatration? By the looks of it it's probally like 14ga 304ss aka it's not made to take a turbo sitting on top of it. If it's at least 10sch 304 then it's "ok" but still not as thick as i'd make it.

Point is, good manifolds have alot more to them then looking nice and working for 10k, report back at 50k, and i'll bet it's cracked. If you want a good manifold, i'd reccomend 40sch 304ss or even better 321ss with all the welds backpurged. Then i'd trust it forever

 

You mean you don't back-purge ALL SS (TIG) welding?



-Ted

 

I find it strange that you get on here and bragg about how well you manifold perfed running 9lbs?? at 300hp. Those are barely over stock numbers. Crank up the boost to 16, put down 400 and do a tracking session and report back.