"Best" Exhaust Manifold for FD Single Turbo?
 

Yes, I have searched the forums before posting and of course "best" is subjective. But I didn't really find anyone who was doing comparisons. Would love to hear from people who have tried different ones or had great success with certain brands.
A few that I have found in my searches are
Turblown (seems to be pretty popular)
VinnyFab
SAS autoworks

I'll be looking to get between 400-500rwhp from my motor with a large streetport after changing the 99' twins to a single. Car is a 94' Rx7
Thank you in advance!

it might help to define that a little more. best as in fits the car, maybe with the air pump? best as in lasts a really long time? best as in has some flow advantage over another? or maybe wastegate placement/quantity?
i've never seen anyone test just the manifold, its more like best fit, cast vs not and what you can actually buy

I'd say best would meet all those criteria. You'd think that someone would have tested vband VS twin scroll. Short vs long length. There has to be a reason turblown made a longer version of their manifold. (they probably posted about it somewhere in here but i haven't been able to find it)

Pros and cons of cast vs welded ect.

you’d be better served not to follow the youboob attention harlot crowd

cast vs welded is dependent on design as much as quality of fabrication

the cast one with the long runner from the rear rotor that has the horrible bend into the turbo flange is awful imo, being cast doesn’t overcome the flow & pulse imbalance issue

sending you a pm with a web link
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I think you're confusing cars. The FC has the Turblown manifold. It actually just made 670whp on the G40-900, ~400lb-ft at ~4400rpm, 670hp at ~7500rpm, E85 fuel.


https://cimg4.ibsrv.net/gimg/www.rx7...04642f2411.jpg


On the C5 Vette, he had an old fabricated manifold and then had a new one fabricated.

You're right! I don't follow too closely, I just watched a couple videos so admittedly I got confused. That's way cool. Big numbers.

As far as I can tell, @rdahm 's FC RX7looks to have the Turblown FC3S manifold, which is different than the short one for the FD. It's visible around 16:30 in the video.

https://turbosource.com/products/tur...turbo-manifold
https://turbosource.com/collections/...turbo-manifold

The even runner lengths on the FC3S manifold look like a good idea. I suspect it might not have enough clearance against the frame rail or shock tower of the FD, hopefully someone who knows more can chime in.

when bad choices are made, then followed by changing to the correct choices, the results will always seem almost … miraculous.

the thing is, the correct choices were all well known and documented. It’s like sailing around the world to visit the port one hour away and then bragging about the journey to get there. :suspect:

yes, he stated it was an FD and I referenced the correct “awful” S-bend manifold in the previous post. Now being discussed in the 8374 thread.

ps: literally raining turbo manifolds in the FS area lately
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Yeah definitely can speak from genuine experience here. I dont like just being told the right solution i love testing it. About to release a video today on everything used on the fc to make 700. the good and bad. But whats really the key thing for exhaust manifolds is divided. you make so much more low end torque with t4 divided than v band.

There is alot of theory on runner length but imo shorter is better. I have EMAP sensors sampling at 1ms (1000 times a second) and i can see the exhaust pulses and vacuum pulses follow. you can see when they start to build and create frequencies as they crash into each other. Especially when the turbo is making juice, the pulse hits the spinning blades but a shockwave actually goes backwards too. ive noticed that can affect engines with massive overlap. AKA porting the exhaust upward and going bridge or semi pp. to the point where 15 percent of the time, fuel can be pulled straight through the intake to exhaust and never make it to the motor.

So on a stock/street port engine definitely keeping the hot parts short help with heat management and pulse strength to the turbine. I dont know the answer for massively ported engines yet.

The wild piece of this next video is actually measuring the FD stock intake manifold limits. Sure enough 700hp at 7-9000rppm its a 100hp drop. Above that i bet its worse.

https://cimg5.ibsrv.net/gimg/www.rx7...9bd885ca32.png
Ignore the circled parts, i was just showing fuelab that their single brushless pump kicks ass at this level. The top red line is EMAP. you can see the pulses and the harmonics at about 6000 rpm. Seeing the pulses strong enough to be measured by a mediocre pressure sensor certainly reinforces the turblown cast manifold benefits.

I just responded on your YouTube channel about the fuel pump.

Didn't know that Fuelab made this. I was looking at the TI kit, but will look into this one. Did you go with their 625lph or 1100lph pump? The 1100lph seems like way overkill.

Are you running all -8AN to the fuel rail or did you go -10?

Eric

Appreciate your responses Rob, but am going to challenge the last statement as being more off-the-cuff speculation than factual. The issue with most fabricated manifolds are relative to proper fabrication and welding processes along with material type. Otherwise your own 26B exhaust manifold in T321 Sch. 5 pipe (0.065” wall thickness) would be highly suspect in that regard. Which is going to see more pulse strength than most 4-port 13B engines.

I know it’s not though, which is relative to the response. Because T304 material is not really suitable for a rotary manifold, but people can get away with it using Sch. 10 thickness (0.109”) or more if it’s fabricated and welded to a high enough standard. It could still eventually have an issue given enough time dealling with thermal stress and cycling. So sure, the T347 cast manifold is good, but T321 is better still, but not generally used for casting.

Thickness helps and going lightweight has an eventual price as even using the right material has it’s limitation over time. The NA Renesis race manifold I built back in 2006 using 18 & 20 Ga. (0.049”/0.035”) T321 material was retired in 2014 due to thermal fatigue. Even Inconel 625 has an eventual life span given the thicknesses used, such as 22 or 24 Ga. wall thickness used on F1 engines.

And even assuming you can get a cast manifold for a particular chassis (RX8 REW as an example), it’s still not a guarantee of being beneficial. There’s absolutely no reason for the hard runner kink circled below to exist, in addition to the disproportionate runner length issue:

https://cimg9.ibsrv.net/gimg/www.rx7...cc89ed55d.jpeg
totally fubar casting design …


A less than optimum design is still just that whether cast or not. I get that running a youtube channel with high resource demands will require a certain level of commercialized sales merchandising though.
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That is just packaging. An 8374 is a large turbo, and with the frame rails in the way there are only a few options to make it fit.

If you want short / equal length, you need a different turbo or more likely a different chassis. That is the shortest manifold available that will fit an EFR. Up to you if you want the benefits of a super short manifold, vs a better max flowing longer manifold, that is up to you and your build goals.

Turblown has always been up-front about the limitations of the short manifold. They offer a longer manifold and recommend it for 500hp+, they know it's not a one-fits-all situation.

Artec and HKS both offer a similar manifold, because that's what fits in the available space.

no, it’s the usual lack of understanding

https://cimg2.ibsrv.net/gimg/www.rx7...35138fde7.jpeg

when making molds, 3D printing, or multi-axis CNC machining, you’re not bound to putting a predefined elbow shape on the outside of a flange, It can start the bend radius right at the flange mounting face, vary the radius, vary the shaping/contouring, add material wherever it’s needed, etc. to be completely organic to suit the requirement. The port starts at the turbine housing and the shaping and fitment to it starts there.

I still say the overall intake design is not correct either, just as I said about the original V1 version from the beginning.
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I think you should ask them, I bet they have a good reason. Like you said, they could have done many different things. Looks like they chose to have the exhaust point straight into the turbo, instead of the side of the scroll. Seems reasonable. Consider the entire package not the one piece by itself.

Dyno testing so far is confirming the intake is a better design than OEM for high hp and high rpm, so that's 0 for you, 1 for them. Backed up by quite a few separate dynos. With Elite finally going bankrupt for (hopefully) the last time, a new intake option is welcome. Pro-Jay is very much full throttle only performance.


You're always so fucking salty. I thought Jesus was your mentor, you need to follow his example and improve yourself bro.

you understand even less about that particular subject, but otherwise go back and look at the welded version and compare it to the cast one.
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What subject?

Mr2peak,
It appears to me from the construction of the cast turblown manifolds they had fabricated manifolds that they deemed worked well and put the turbo where they wanted so they went ahead and replicated them with their casting molds.

They made some improvements along thevway such as a continuous taper on their long runner ewg manifold.

You can read more of my opinions and see pics of the cast iwg manifold I am using to solve some of the issues the turblowncast short iwg manifold has here if you like-

https://www.rx7club.com/single-turbo...1118515/page6/

i wonder if that 6000rpm thing would move if the exhaust manifold changed lengths?
congrats on the 700hp

^^if anything deserves a salty answer it’s this one. Instead I’m going to say that it’s not even clear what specifically you think I’m being salty about or why it has anything to do about anything? Maybe you lived a life so full of lies that a straight up honest, sincere answer which has no intent or meaning beyond the actual words leads you to be confused or in doubt?

Otherwise, did I bare false witness against you, or steal from you, or commit adultry against you, or murder, and honestly I can’t think of anything you have in your possession or capacity that would be enviable, so what is it? Everything going on here is all just a bunch of flesh and blood nonsense any way; the here today, and gone tomorrow. And it’s just like flesh & blood to confuse the sappy feelings based love of the world rather than the true spiritual love of unconditional commitment, sacrifice, duty, and obedience where feelings and emotions get zero consideration, i.e. a servant - king relationship, where any moment can be either to live or off with your head.

Or maybe you were somehow misinformed about me regarding what is given to helping people with true needs rather than this forum garbage; the poor, the orphans, or the widows/elderly? If you think I’m salty, how about referring to people as dogs and hogs (swine), or straight up calling a woman who is begging to have her dying daughter healed a dog to her face, or grieving about how much longer will you have to put up with the whole insufferable lot of us? No, all you know is the world, you speak to it, and it hears you; but you neither know nor hear me. Just the same, you would still receive the last shirt off my back if your own need was true and greater than my own.

Otherwise, the supplier of that product has a lot saltier things said about him than anything I ever did. And that one particular reference, or the 2nd one added on, doesn’t condemn everything they offer or do even though a saltier lot than me will say otherwise. Further still, you can take one stance of it just being criticism trying to belittle someone beneath them, or you can take the stance that it’s intended to correct and improve it for the better of everyone; the glass being half full or half empty.

Just who is responsible for the stance they choose to take?
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What do you think of the new Arctek manifold? I haven't seen any dynos yet

Interesting looking. Hadn't seen that before, thanks for sharing. In terms of the length and shape of the secondary runner it doesn't look all that different than the Turblown manifold to me. Interested to hear other opinions, though.

Artec manifold is another nice option.

We dont know if EFRs fit in an FD with it, so I wasnt going to cough up the $ to find out.

I would have been interested in Artec T4 and the IWG EFR 8374. Extend the amount of gas pedal/rpms you get before the external gate cracks.

Newer revised HKS cast for FD is nice option too, though I have heard it does NOT fit EFR 8374.

I had a REALLY hard time not going Turblown long runner EWG cast. Just decided I want throttle response as a priority and shorter runners may help.

I actually spoke with the Artec team and when they released the EWG model, they were going to gift me one in exchange for a review. I asked a lot of technical questions about their manifold. After learning more, I turned down their manifold. It's similar to HKS older manifold, not equal length, not separated, WG placement wasn't ideal and it didn't have added bungs for sensors.

I still like the old Howard Coleman design.i have been asking him to make more of those as I think they make more sense.

Eric

I thought Arctek was essentially the HKS manifold, but with a fully divided wastegate runner right up to the valve face. All their literature and pics show it as fully divided, I'm surprised to hear otherwise.

Even the long runner Turblown manifold is un-equal length. And if you want an e-gate, it's twice the cost.

The FD has packaging issues with the frame rail. If you want equal length, you will have more bends. If you want a short manifold, you will have tighter bends. It's just a reality of the chassis unless you get creative with a sawzall and a welder..