andythejock01wrx

This sounds v interesting.

BTW, when Andy F used DeltaDash on my car he got within 2bhp of the Dastek RR run I had done a few weeks later. Accurate enough I reckon !

B0DSKI

iTrader: (17)

I wonder where that is

scoobysmiff

iTrader: (2)

Well this could be interesting then, i hope this manages to get sorted so we can get decent comparisons at last, once that has been done people can make their own minds up, well done Zak for accepting the challenge

Northern Nick

iTrader: (1)

I'd say it will make interesting reading .

Leg@cy

iTrader: (2)

Interesting reading.....

Adding this so i can keep track of the findings....

scoobysmiff

iTrader: (2)

Well i managed to get my ported headers, up pipe and decat fitted at the weekend, and the car really is now working very well indeed
I have noticed that the spool is earlier, i get 1 bar at 3k (completely std car with VF24 apart from headers & decat) and it now revs far better at the top end, before it didn't seem to be overly happy (although it would do it ) to rev past 7k, now it does it with an enthusiasm that was absent before. On the test run that was i had to be careful not to over rev and WOT in any gear produces some decent forward momentum from 3k onwards.
Boost has risen by .2bar and the best bit is that will be better once it's had the new turbo, injectors, FMIC and ECU fitted and mapped

I have managed to speak to Harvey and although he has not seen this thread yet due to other commitments he is keen to carry out a back to back test as proposed but agrees that the logistics could be a problem, i think it would be better to email him direct to see what can be done to enable this to happen

Northern Nick

iTrader: (1)

Did we get any further with the back to back test?

Northern Nick

iTrader: (1)

I have just recieved my Kakumei GT Spec II headers/manifold from - Flat4online.co.uk Subaru Impreza Mitsubishi Evolution EVO Walbro Fuel Pumps Injectors Intercoolers and I can only say that they look to good to be true. I cant see anything any different from what I have seen on here or to anything I have seen on the internet in relation to genuine GT Spec II headers or Tomei GT Spec headers. The onlt thing that is different is from what I can see on some picture of genuine GT Spec headers, the tight bend doesn't have a weld on it, its a true mandral bent peice of pipe, but I haven't seen a clear shot of the underside so cant be 100% if it is or not. The Kakumei headers have the same cut and join as shown previous, like the RCM, Zen, GT Spec (?)



Even came with all the gaskets ready to fit.

Ian

iTrader: (10)

just looked at my set, and they have the same weld there as well.

Ian

iTrader: (10)

woops just relised that, that is my pic lol

Northern Nick

iTrader: (1)

lol

Right, heres some pici's of the Kakumei GT Spec headers for those interested, look at the quality of the welds and the port openings, they are the best I have seen on an exhaust pipe of this price. The camara has picked up on one or two bits that are visable in normal light, just the flash of the camera has highlighted them but I'm sure even genuine GT Spec have the same minor defects.

I was that impressed when the set I bought for my car came on Tuesday, I ordered a second set on wednesday to fit to a classic and they came today.

Enough babbeling, have a look for yourselves, click on the picture to better the quality

Andy.F

Those look like the headers I normally identify as GT spec Nick, the Kakumi ones I have previously seen didn't have such tidy 'auto' welding or a cone inside the collector.

Ian

iTrader: (10)

on the last 2 pics, mine have got that same stamp at the bottom. think it must be the makers mark., and again, they look the same as the ones that i have got.

i had a scan on google etc, but can only fint top shots of the headers when i put in gt spec etc

Northern Nick

iTrader: (1)

Andy, I had a really good crack with Scott Lawson and he said they where far better than ebay sh*te (well he would) and I believed him because he also told me that the Kakumei system I bought was second to none in quality, and it was, not sure if all Kakumei exhaust are of the same quality regarding your comments. We will see how they perform in the next few months and hopefully they will do well.

DaOne,

I found the same thing when google imaging GT Spec headers, I did find 1 or 2 where you could just kinda see through the pipes to see the part where the weld should be and I couldn't see it

Ian

iTrader: (10)

also, do you get a fitting kit with these, or is it just gaskets?

Northern Nick

iTrader: (1)

There isn't a fitting kit actually no but I think all I need is 3x M10x30 flanged bolts & nuts for the headers to up-pipe and 3x M10x30 studs and nuts for the up-pipe to turbo, they will only cost about £5 for quality stainless steel ones, cant complain at that.

Should have the classic set fit by the end of next week (There going on Baz's Red Classic Andy) so should see if we get earlier spool and higher boost from them over the "ever so common" ebay one piece tubular headers and flexi up-pipe.

Will report our findings when we find them

Andy.F

They should be an improvement over the one piece ones for sure.

Maybe the ones I have seen previously were Kakumei replicas, those in the pics are the same headers that are marketed as GT spec.

Bartop

I've recently had a set of Perrin EL headers fitted and had them ceramic coated by zircotech. Excellent quality and the sound is spot on.

321t and APS up pipe fitted as well so can post some results once the mapping has been completed..

Andy.F

Interesting, the Perrin headers get good reports, are you using a later sump ?

SSCJAY

You have to have the 2.5l sti sump (has one of the corners cut off), or they do not fit. My brother has them on his car and although he misses the burble, they sound awesome at high rpm.

Bartop

Yep - have a 2.5 built engine with forged pistons, full details in my profile. I believe it's a JDM sump..

scoobysmiff

iTrader: (2)

What is the internal dia of the up pipe?

Northern Nick

iTrader: (1)

Im not sure but i'll measure it if you want me to.

It has the venturi fitted to speed exhaust gases in it to help spool but I'll check diameter later tonight and let you know.

Regards,

Ian

iTrader: (10)

turbo end has a small lip on it and it measures
51mm or 2 inch

and the header end
55mm or 2.18 inch

scoobysmiff

iTrader: (2)

i know that it has a venturi, but is that not just a bit too big for good spool characteristics, whilst top end is prob improved? just looking at the std size for comparison and it's considerably bigger.
I just want to find out the benefit from fitting these headers as opposed to ported Std ones, I have a V4 Sti and am thinking that the faster gasses from the higher rev limit may benefit from a set of these headers??? but i will be retaining 2.0ltr's so don't want to loose spool

Ian

iTrader: (10)

on my car i am running a 20g etc, putting out just over 360. alot of people on here say ported ones are a better option for 350 and less.

prob best to speak to your mapper to see what they recomend

Northern Nick

iTrader: (1)

Right, on the Kakumei GT Spec, at the 3 bolt flange the up-pipe is 57-58mm I/D and at the turbo flange the up-pipe is 52-53mm I/D. My tape measure is old so the end maybe slightly inacurate, hence 52-53mm

Hope that helps.

I'm hopefully going to see about 400hp with these fitted but as long as its drives rapidly scarely, I'll be happy.

Northern Nick

iTrader: (1)

Got the headers wrapped and fitted over the Christmas period (How long ago does that seem ) For anybody interested that are about to wrap a set of these or similar GT Spec headers I'd recommend a 50m x 50mm roll of wrap, the two longer header pipes use about 11m each to wrap from collector to head flange and the short two take about 7m each to wrap. The collector housing took about 4m to wrap and the up-pipe took 6m to wrap, thats all wrapping with a half over lay. Thats a total of 46m by my reckoning. There will be spare at the end of each run but I think its better than running short and joining halfway along. Stainless Steel Ties can be used to secure the wrap ()

Anyway, getting back to the headers, they've been on the car for nearly a month and my mate say he still cant believe the difference they've made over over the cheaper one piece ebay headers you can buy. Firstly the car feels free-er, a lot better to drive off boost feeling more responsive (Cant comment with reference to standard as the previous headers have been on for sometime). The car has also lost the harsh rough sound it had now having a smooth even burble instead of a lumpy burble if that makes sense. It hasn't effected boost levels haven't much altered much maybe only increasing 0.2 of 0.3 of a bar (which he will be coming to see you about Andy) and spool is sooner getting full boost at about 4k in third gear (TD05 16g @ 1.4bar on a '93 WRX Classic). Te fit was good also, only the top bolt on the three bolt flange was tricky to do, the rest was a doddle.

A blast on the rolling road would be interesting as 310hp 315lbs/ft was acheived with the previous headers.

I've still yet to fit them to mine but comparing standard to Kakumei GT Spec headers on my car wont be possible as the turbo will be changed at the same time alot with a few other alterations.

So I think recommending them for the classic goes without saying , I'm sure the benefits will be very similar on the newage.

harvey

iTrader: (48)

Nick: I still want to do back to back tests, my ported headers and uppipe compared with tubular headers.
I have a donor car with a VF28 but it is only 318 bhp at present but it does have my ported headers on so all that is needed is for someone to loan a set of tubular headers.
Alternatively we get another vehicle with more power already fitted with tubular headers or my ported headers and uppipe but someone would have to volunteer a vehicle.
I am happy to look after the fitting and removal of the headers and I am sure we can negotiate preferential rates for a couple of rolling road runs.
I will be missing for about a week but we could pick this up after that time or others could make their suggestions in the meantime.
I am happy my ported headers will be superior to at least 400 bhp and probably hold their own to 450 bhp.
My 95 WRX on one of my 05-06 20g is running a solid 422 bhp on V-Power and 2mls per litre NF with a Simtek.

Jay m A

iTrader: (2)

Is that with the ph1 hydraulic heads Harvey?

cheers