all are very similar.None have a turbo supplied with them. LOL sure thier makers will probably say thiers is better.
I do like Nitro Danns Twismount dump pipe. I love the Kraken Cast Iron Manifpold I do know the manifold of the Bofi & Kraken are identical in designs except 1 is Stainless Steel the other is cast Iron.
If Nitro Danns was around 3 weeks ago I would have had a serious decision. Kraken is a cast iron manifopld. But nitro Dan has the twistmound. I like both. But ive gone for the Kraken.
discuss, thoughts, opinions. please refrain from soiling anyone name or work here. I know we have freedom of expression but please do it somewhere else.
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I like Dann's DP, I don't understand the reasoning behind the divorced dump but I'm sure it's valid. What I like is how direct the dump is with very few bends. I always like Dann's work.
I like the Kraken because it's cast, super strong and quite cheap for what it is. This guy is really putting in work right now, he has manifolds for different generations of MX-5, different mounts, different turbos, creates downpipes for them (some with a cast elbow even), and will fab a whole exhaust in 3" if you like. I think he even does full IC kits for NAs.
The Bofi seems like they're asking too much IMO. It's the most expensive and it doesn't even exist yet, it's untested.
I think the divorced dump pipe its aimed at better response?
at least we now know we still have Nitro Danns fabrication skills available. I wonder if they could talk about a cold air box for the NA.....in aluminum.....so i can polish it.
Well done mate! Did you go the older higher mount Kraken or the new lower mount one?.
The new lower mount one I believe requires the housing where the radiator hose connects to be modified but I think it’s a better idea with a straighter dump pipe, always pros and cons and the guys are working hard on a quality product with no failures so far that I have heard.
I think I’ll be going Danns when the time comes just because he has given me advice in the past and been great help so I would like to support him, as far as workmanship the welds on the washer bottle I got from him are just drool worthy.
I think Danns twistmount will handle all the abuse I can throw at it.
The pros for me is Locally made. I like the look. I like the design. I can connect it to the hole in my firewall a little easier than the other options due to turbo placement.
In saying this if Dann stops supplying I’ll also go the Kraken.
Very excited for you mate, this will get interesting.
I believe it's about exhaust flow. The gasses more easily exit the turbo due to a more direct path with reduced turns. A top mount has to take an almost 90* bend straight down, then another bend back to get under the car. The low mounted twist mount is much straighter.
How much of a difference it makes, and if its really noticeable I'm not sure.
(I wrote a huge post that would have bored most people and deleted it and wrote this)
Comparing common manifold styles there are clear compromises made.
The compromises which are often chosen are based on marketability rather than theory or testing. In terms of manifolds the most common popular design seen is the equal length long tube manifold, either high mount or low mount. This design is particularly popular among casual enthusiasts because everyones favourite serious race machines use this design. Dedicated competition racecars have a few things in common with one another but not in common with the typical turbocharged mx5.
If you want maximum performance across a narrow powerband such as in everyones favourite dedicated racecars, you use a big turbo, and with a big turbo you get a narrow performance window, so you have a close ratio gearbox and you make design choices which help to further concentrate the powerband at the top end. You use big diameter runners, and you build the manifold like a set of headers, long, tuned equal length and this can be done really nicely. Take this F1 car engine for example.
Now compare it to a similar design contorted to fit inside an MX5 engine bay:
Another consideration is that the exhaust ports are angled upwards and yet the manifold above immediately bends very sharply downward.
You just cannot fit a long tube equal length manifold in an MX5 engine bay using typical racecar design, so even if we were using a big enough turbo and camshafts, sequential gearbox etc our longtube manifold will have compromises in the form of many bends, reducing efficiency, unlike our F1 example above. In a longtube MX5 manifold you have 90* turns immediately after the exhaust enters the manifold and a total amount of turns exceeding one degrees, with 4-5 feet of tube. The exhaust ports are angled up, and many of these manifolds immediately bend sharply down, its not well thought out design. Additionally, the large surface area of such a big manifold means a lot of heat energy is radiated out from it heating the engine bay and reducing energy which we want to use to spool the turbo, typically meaning later response at low rpm. A Twistmount uses 3 feet of tube and less than half as many bends, and the runners come out of the engine matching the exhaust port angle for much better gas flow.
The twistmount also gives an extremely straight downpipe path meaning better flow for both power and response, and overall packaging is much nicer and easier to deal with.
So basically the twistmount is designed specifically to get the results MX5 owners need for performance and many popular designs are made based on what is popular on dedicated racecars. Most turbocharged performance cars have turbochargers which take a little while to come onto boost, sharply ramp up onto boost, and then taper off flat at the top end. Take this SR20 dyno for example, You can see the turbo building up, the dyno chart starts off looking like a skateboard ramp as it winds up onto boost:
Then watch this MX5 dyno using a twistmount.
This comparison is extremely fair, the SR20 is 2L uses a very well respected long tube manifold by 6Boost, and has a garrett GTX2863r tuned by a very reputable local tuner. The MX5 is 1.8L, uses a Twistmount and has a slightly larger GTX2867r, which should mean less response, but notice the way the MX5 performs as the run starts with silky smooth power and absolutely no skateboard ramp at all climaxing at over 450whp.
Curious as to what solutions are required with the water pump neck. I believe most turbos will get in the way.....for the Kracken version at least the neck needs to be shortened.
are there ready made solutions for this or do I need to get it shortened at a welding shop?
sure thier makers will probably say thiers is better.
