Tegiwa manifold and Decat


stefanoo18

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Feb 2, 2013
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Was looking at getting a Tegiwa 4-2-1 manifold with a Tegiwa 2.5" decat too, yous think its worth the money at 400quid? and will i feel much of a difference?
Thinking it would add 15-25bhp, would that be right?

Cheers
 
Well worth it IMO. Your thoughts on gains might be a bit optimistic but it will deffo make an improvement. Even better with a remap.
 
okay cheers! forgot to say it was for a jordan civic.
Most likely get one when i get paid at the end of this month then!
 
more like 1.5 to 2.5 hp, especially if you leave it on standard map. But if nothing else it is going to sound a bit better!
 
Should be good for 7-12bhp.
We saw a 7.2bhp gain from just the manifold and that was versus a 98spec 4-1.
 
Should be good for 7-12bhp.
We saw a 7.2bhp gain from just the manifold and that was versus a 98spec 4-1.

What car was that though? Was the rest of the exhaust system standard? Standard map? I personally don't believe that exhaust mani and decat will get you that kind of gain (eg 12bhp) without other mods (intake, complete exhaust etc...) EK4 exhaust system is fairly restrictive and will therefore reduce any possible gains imho.
 
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If you got 7.2 hp gains fair play good result for just a bolt on tegiwa must be good manifold but like oifovo id beleive more if was mapped in. but thumbs up if true :nice:
 
It was on a 98spec ITR, same day back to back dynoing and it was VS a 98spec 4-1 which as you know is already an excellent header

Thanks
 
No other test has seen such high gains though has it?
Just to get a different perspective on the claim.
Haven't seen anyone gain that after fiting
 
I think tegiwa get abit of a hard time tbh.
I mean if this thread was about the toda mani they've copied then no one would be doubting the power claims,
Its exactly the same manifold but with a cheaper name stamped onit.
What do toda quote the gains to be?
 
I think tegiwa get abit of a hard time tbh.
I mean if this thread was about the toda mani they've copied then no one would be doubting the power claims,
Its exactly the same manifold but with a cheaper name stamped onit.
What do toda quote the gains to be?

I have noticed this, tegiwa always seem to get it tight on here lol!

Their manifold does look good :) the gains will be good as it is basically a toda
 
I think tegiwa get abit of a hard time tbh.
I mean if this thread was about the toda mani they've copied then no one would be doubting the power claims,
Its exactly the same manifold but with a cheaper name stamped onit.
What do toda quote the gains to be?

As high as power increases go pretty much
 
I am not bashing tegiwa in fact I would be happy to put their manifold on my car. I m just questioning the possible gains which I simply believe to be exaggerated. Maybe it has something to do with my scientific training that I am a bit sceptic like that, but they are comparing a 190 bhp car with a 160 bhp car, plus there is no mention of any other supporting mods, map etc. Anyone with elemental knowledge of how car mods work knows that mods affect each other, so the fact that they saw that kind of gain in a single car cannot be extrapolated like that to other cars, especially when nothing else is known about that car's mods. Personally I would prefer the answer along the lines of 'Possible performance gains always depend on the spec of the car in question and can therefore vary, but just to give you an example we measured a 7 hp increase after swapping a stock manifold for our own in a 98 spec dc2 which also had these supporting mods and was mapped/was completely stock otherwise or whatever. I understand that predicting any possible gains will always be very difficult, but that does not mean they should just pull a value out of thin air.
 
IT HAPPENED - FACT!
Call TDI North and ask for Paul.

This was from over two years ago.

Right - the results are IN!!! 8) 8)
We had a great day with Paul and Lou @ TDI-North - These are the people to go to if you need and work done on your car! Paul is a Magician
And at last - we have a manifold that we are happy to sell!!

The base car - PY 98spec ITR (OEM Airbox, 98spec manifold, Fujitsubo Catback, TEGIWA Decat)

We did 5 different combination runs

Base car 197.4bhp & 141.7ftlb
Base car + TEGIWA Whale***** Intake +3.4bhp & +0.6ftlb
Base car + TEGIWA Airbox +5.0bhp & +3.3ftlb
Base car + TEGIWA Manifold +7.2bhp & +0.9ftlb
Base car + TEGIWA Manifold & Airbox +10.2bhp & +2.2ftlb

The above figures are peaks - see the graphs for other area's
Remember these results are literally back to back runs with zero tuning in between. In a few weeks we will do a few more runs with Cam Gears & Hondata S300
 
Nobody is denying the test took place, it's just the statistics you're using. You say '7-12 bhp' increase. I do not see a 12bhp increase in those figures, and a Fujitsubo Catback makes the car not standard. Perhaps add an asterisk and some clarity?
 
IT HAPPENED - FACT!
Call TDI North and ask for Paul.

This was from over two years ago.

I am not disputing that at you have done the test! I believe you did and I also believe you did measure those gains, I am just stating that you can't extrapolate it like that! There are terms like sample size, sample variation etc that you are simply not addressing at all. To be able to make such claims you would have to measure the gains in tens if not hundreds of different cars and then that would give you some kind of mean value and range of possible expected gains, but basing your predictions on a single measurement of a different car is quite simply wrong, sorry! I appreciate that such testing would be very costly and to a degree unnecessary, as the manifold has proven to be very good times and times again by the numerous happy users, but that does not change the fact that your stats are completely off. Ask any statistician....
 
^ that isn't only applicatible to tegiwa though is it.
I mean look at all the parts for sale that quote such and such an improvement that is obviously complete bollocks, at least tegiwa have actually seen the gain they are advertising.
Basically what I'm saying is the tegiwa manifold has the ability to add 7+hp to a bseries engine.(which it does) so why are they in the wrong for saying so?
To say it WILL add 7+hp is wrong however
 
^ that isn't only applicatible to tegiwa though is it.
I mean look at all the parts for sale that quote such and such an improvement that is obviously complete bollocks, at least tegiwa have actually seen the gain they are advertising.
Basically what I'm saying is the tegiwa manifold has the ability to add 7+hp to a bseries engine.(which it does) so why are they in the wrong for saying so?
To say it WILL add 7+hp is wrong however

Absolutely, that applies to every company! The problem here is that they (and any other company with similar claims) don't seem to understand (or I personally believe rather pretend they don't) how the testing works. Imagine you have an unlimited budget and decide to build the ultimate B16B engine. You get ITBs, custome forged titanium pistons, anything you want. And then you put a stock manifold on it. Obviously that's going to restrict the power gains quite considerably! Then you go and put a Tegiwa/Skunk2/Toda/whatever manifold on it and WOW! You have just gained 15hp!!!!! That's amazing what a single thing that we changed can do, isn't it! Everyone should now run and buy one! This is obviously far stretched an example and not even close to what Tegiwa did, from the info provided the only mod done to the car was an aftermarket cat back. But how do you know it was not the combination of the two that gave those gains? Maybe the catback on its own only gives 2hp, the manifold also gives 2hp but them two combined give 9! This is something that's called confounding factor, and it is vital in any kind of testing that these are tightly controlled (although it is usually almost impossible to eliminate them completely!) As you said, it is not at all just Tegiwa, in fact most big companies use these 'pseudostatistics' on a daily basis to fool general public into shopping in their store or buying their toothpaste/washing powder etc....
 
I do see what your saying and you are right.
But to find 10's or 100's of perfectly stock cars with owners willing to do these tests is virtually impossible. So tegiwa have done the best they can do by getting a stockish car and testing it. Obviously they are going to claim the maximum figure because they want to sell them, and of they did test it like you say then the price would be through the roof.

This is no doubt why they copied the toda, 1. Everyone loves toda parts 2. Toda no doubt tested there mani a fair bit more than tegiwa.
So this is obvious choice for them to make a copy so that people can get toda-type gains for cheap. If they did all the testing they would have to market same price as a toda one to cover costs.
 
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