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Discussion Starter · #1 ·
Anyone have the Gruppe-S manifold? If so are you impressed? Where were the power gains? Dyno charts?

Thanks in advance

Joe
 

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Sorry don't have it, but *Bump* for the good question ;)

I read that GOD had positive results from the gt spec headers if I recall correctly.

I wounder how it compares to the grupps-s type ?
 

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In my opinion, not even a new manifold will make your car fast joe :tongue: :wiggles:
 

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I have one on order, but won't receive it for the next week or two... Even so, I am not even sure if I'm gonna install the thing this year.... REALLY busy with school and stuff, and it is hard to find time to go for tuning as well :(

From what I have read though, it is almost identical to the GT spec, so they must have pretty similar power gains.... i.e... loss in low end, gain in top end..
 

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According to gruppe-s' dyno chart (http://www.gruppe-s.com/) the gains from the manifold were 13 hp and nearly 20 flb at the wheels, all of it above 3,000 RPMs. There looks to be a little power loss below 2,500. They claim those gains were on an otherwise stock car, so it is likely that bigger gains are likely with further mods. And let's face it $400 is cheap for those gains, especially if you've already done the big stuff.

Zero Sports header was tested at nearly 25 hp increase in Japan's Hyper Rev magazine. However, at a cost of $1,600 they are a costly alternative.
 

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Right - I think the point here is that Headers on the boxer engine have been given a bum rap by many tuners (TXS et al) and the only one who offers a qualified approval is Dan/God for the insanely expensive MaximWorks piece ($1600). And even he says to spend money elsewhere, first.

So we are seeking out independent verification on it, from end users. Before/after dynos would be good, before/after quarter miles would be better :) Sometimes vendors lie, sometimes dynos mis-represent.

For a turbo car, headers would seem like an obvious point of improvement, but it begs the question of why so many tuners are against them ?

There's anecdotal evidence about the E-Street (?) 9 sec WRX with practically the entire engine replaced/rebeuilt but merely a port-matched OEM header.
 

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Discussion Starter · #8 ·
Well I have a stage 4 plus with a VF-23 and I thought it might give me a little more top end. I dont think $500 is too much to pay for 15 hp and 20 ft lbs at the wheels either.... plus Ill have it ceramic coated and probably pick up a little more.

And I think it says those dyno numbers are with turbo back with a single cat and an up-pipe - which sounds more reasonable to me.

My main concern is fitment - so Id be thankful to hear how they went in from those of you who are installing.

thanks again,

Joe
 

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WRX_Wagon said:

There's anecdotal evidence about the E-Street (?) 9 sec WRX with practically the entire engine replaced/rebeuilt but merely a port-matched OEM header.
What you need to remember about headers is that although they add power up top, they also introduce some lag into your system... This is most likely why ESX don't use one... Their turbo is most likely already big enough with monster lag that they don't want even more lag being introduced into the system by headers...

Also, SOA has a great deal of say as to what goes onto the car, and what doesn't... If ESX had it their way, their car would be stripped without an interior, but SOA wouldn't allow them to do so....

Just because the established names are not doing something does not mean anything....

We all now know about the power gains that can be had from WI/AI.... Does ESX run such a system on their car??? Nope! Vishnu? Nope! TurboXS? Nope!
 

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i have the gruppe-s headers with jet-hot 2000 coating and wrap and spray. no noticable loss down low...no noticable added lag (keep in mind, i have the STi)...but it kicks much harder when boost kicks in.

installation was a breeze. i had a slight leak when the engine was cold, so i bought the dyno engineering gaskets, and redid the whole thing in 5 hours (took off everything from the block to the midpipe and back together again). its kinda fun too...but thats just me.

however, i think the STi ECU is too smart for its own good and has pulled timing since the initial installation of the header...so it doesnt feel like it kicks as hard as it did at first. UTEC should fix that... :)
 

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Discussion Starter · #12 ·
Well since I have a VF23 and a relatively small intercooler (STI top mount) I really dont have much lag - so Id be willing to trade the minimal amount for the extra top end.


happasaiyan,

1. Be careful about those wrap products. Ive see them catch fire and its really not pretty. Plus they dry out in a few thousand miles and crumble into pieces. And since youre already ceramic coated its probably not making a difference anyway.

2. When you had the leak - had you reused the old gaskets or gotten new OEM ones?


Joe
 

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yeah ive heard about some stories about the wrap...but did theirs have the spray on top? supposedly that keeps the bad stuff out...and i put on 4 coatings to make sure of that. haha. if they do dry out and crumble, ill just take those things off...wouldnt really bother me.

when i had the leak, i got new oem ones. it was kind of weird...i just got some fluttering the first couple times i floored the car after it warmed up. after that it stopped...so i just figured i would replace all the gaskets with those thick ones that supposedly dont leak....and so far, they dont.

and ps- clear out your pm box!! i lost my message to you :confused1
 

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What about the sound difference, i love the boxer sound but i want some headers not only for the cosmetics but the performance but i dont really want to change the throaty sound. I hear equal length are worse for the sound aspects and that non equal length preserve the sound better Can anyone give me an idea of the best header for the job
 

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equal length header = smooth exhaust note, like honda, but deeper.

non-equal length header (gruppe-s) = sounds like you have more aggressive cams. LUMPY!! :D i love it.
 

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Discussion Starter · #16 ·
See equal length headers are useful because the give whats called "chasing effect" to the exhaust gases. This is when the gas leaving through one pipe in the manifold causes a vacuume in the collector, which then sucks the gases exiting from the next cylinder out faster. But they dont do much for turbocharged cars from what I understand. And yeah I would hate to loose that bad ass sound that identifies the car as a Subaru.

As far as the wrap goes - this particular car was a 647whp Supra - so Im sure that if there was spray available the owner bought it. It was that Thermotech stuff. Im not saying that it dosent work - im sure it does what its supposed to.


This is the key - you have your headers coated. If the place was good itll be coated inside and out. If not tell me and Ill tell you where you can have it done for about $150. The purpose of coating or wrap is that you assume that heat passes through the metal quickly - so when you put a barrier on the outside - it keeps it from leaving the exhaust gases. Its not the header you want hot really - its the gases. And youre not going to keep any more heat in than you already have with your coating. So why take the risk?

And im sorry about the message box - its clear now.

thanks,

Joe
 

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the idea was to keep hot air in so it travels faster so spoolup is improved...but also to keep underhood temps down with the wrap.

btw, the jethot 2000 coating is an inside and out coating that protects up to 2400*. my egts have never been above 1550, and only sit at 1200-1300 while cruising at 80 on the expressway...so i dont think i should have a problem with that coating. maybe i will take the wrap off...but then again, that means i would have to take everything off....for a 3rd time :(
 

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NJSubieTech said:

This is the key - you have your headers coated. If the place was good itll be coated inside and out. If not tell me and Ill tell you where you can have it done for about $150. The purpose of coating or wrap is that you assume that heat passes through the metal quickly - so when you put a barrier on the outside - it keeps it from leaving the exhaust gases. Its not the header you want hot really - its the gases. And youre not going to keep any more heat in than you already have with your coating.
So if I follow you, getting the coating inside is to keep the heat of exhaust in, velocity up, etc, getting it coated outside is most likely for cosmetics (or, it can't be avoided in the process of coating the inside). If the coating on the inside is doing its job, there shouldn't be much for the outer coating to do.

This sounds like it should become its own thread ---

what about getting the turbo coated, as what deadbolt offers ?
http://www.deadboltspeed.com/ceramic.htm


Lower underhood temps == good, but what is the effect of "locking" all that heat inside the turbo ?
 

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bump for my good buddy Joe - long time no chat. I can't wait to ride in your car now that your have your UTEC. :D

chris
 
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