The next step of my mods would be turbo and headers. This will get me to around the 400-440bhp mark....

But, I'm not sure if I will be able to afford headers before July. (which is when I'm going on holiday with my car)


What negative effects will I get from not changing the headers?? Do they limit the car to certain power level etc??



Thanks
Chris

 

In my experience, by the time you get to a turbo big enough to make low-mid 400hp, headers offer about 25hp in the midrange 15hp at the very top end, and make little or no difference to spoolup. With turbos in the mid 300hp range, expect moderate gains when on boost but about 300-400rpm later spool when compared to a set of ported standard headers.

 

So if I was going to get a FP Green, or MD321T (depending on money). I would loose some bhp mid and top end, so may struggle getting the 400 mark if I wasn't going to change headers? (yet)

 

Get the two together a bit later in the year. It is a chunk of money to do what you are doing and it will save on remapping fees doing it all in one go.

Also I would consider the extra to go for the T worthwhile

 

Cheers mate.

Did think they sort of should go hand in hand! Will ask the GF for some money....don't think she'll stretch for a T though

 

Thing is, you will always wonder about the T if you dont go that route.

I had FP Green and now MD321.

 

yeah, I fully understand what your saying mate. But I don't know if I can justify the T being double price of the FP Green really. As I think I can get a brand new Green for £800ish. And a T is in the region of £1600 isnt it

Although I do agree, the T is far superior, and I would rather it.....

 

T's come up second hand from time to time.

 

Honestly, it sounds like you need to discuss your upgrade path with someone that can tell you what to buy, in what order so you end up with the right mods to acheive your goals, and not doing some of it twice. That is the service you should expect to get from good tuners. If it's going to cost you £3000 (or instance) then start saving and perhaps buy the right bits as you go, don't be tempted to let a little money burn a hole in your pocket resulting in the wrong parts being purchased.

 

Thanks for the advice I've already bought lots of bits, like FMIC, bigger injectors etc, and the next two things are going to be headers and turbo. I know which headers I want, but aren't 100% on the turbo. I'd like the 321T, but don't know if I can justify the cost really. Unless a 2nd hand one comes along.


Thanks again

 

What is the car? What injectors have you purchased? What are you going to do ECU wise?

 

2003 STI.

Engine mods I've got so far are:
Full turbo back de-cat (inc up and down pip)
K&N CAIK
HKS FPR
ECUTek
Uprated Fuel pump
NGK PFR 7B Plugs

And to go on I have:
FMIC
750cc Injectors (flow matched) and are made by Deatsch Werks
AVCR Boost Controller

And to buy a new turbo and headers.

ECU wise I was just going to get it remapped again.



Thanks a lot for the help!!

 

It's a shame the injectors aren't a little smaller, but hey ho!

On standard turbo you can expect about 350hp with the FMIC and other bits.

For the turbo, I am asked the same question by lots of people, and it's hard to make a good suggestion as it's going to be down to your preference at the end of the day. If you go with something like an 18g you are going to have good midrange, and you could keep the OE injectors which will make it a more straightforward remap and better idle etc.

But, you don't have to buy a turbo and headers at all.

The answer depends on what you want out of it.

 

I thought the mapper could easily control the injectors? I did buy them 'too big' just to future proof them really, in case I go for bigger power.

What I want out of it.....
Really, just a bit more power. I bought the car with a RR graph showing 350bhp already, so would like a bit more, around the 400-420bhp mark. From what I've read, the MD321 series are the ones to go for, but I really don't know if I can justify the extra cost over a FP Green for example?!

 

So do you want a piece of paper with 400hp on it, or do you want a car that you're going to enjoy driving?

 

LOL YES !

Mine only managed 390 bhp (PC guesstimate) so of course I do....

Actually, what I miss is the wallop it had before being mapped (safely !).

AVCR or EVC next ?

dunx

 

Chris - picking up the phone would be a very easy option to chat through the options. It can actually save you a lot of money to talk through your objectives before you start sending.

Zen's number is: 0845 055 9366

 

I'm at work so can't phone unfortunately

I understand about the "piece of paper", but I sort of need something to aim for really. As if someone was aiming for 300bhp, they wouldn't buy a MD321T for example. So my aim is at least 400bhp, but a real nice car at the same time. I've got a few handing mods like ALK, ARB, Droplinks, Coilovers, etc, and going for Geo setup soon.
So thought about the MD321T or FP Green, as these have been tried and tested. As for headers, from what I've read, they all seem to be about the same (tubular ones).

Sorry if I come across ignorant, I don't mean to be I do admit though, I don't know half as much as you guys, and the bits I've already bought are from recommendations on here.



Thanks again.

 

Is it possible to evaluate the plus's and minus's of these turbo's as in the older type journel bearing type(18gram etc) v's the more modern ball-bearing as in the Garret hybrid's. In general the latter costs twice as much.
Is one quicker spooling than the other?
Does one hold boost better higher up the rev range?
How important is build quality, as in 'very good' v's 'exellent' when it's used mainly for the road, setting aside the cheap versions we all here about and comparing like for like useing reputable engineers?

 

My mere MD321H is well short of stressed producing 390 bhp, I'll have to go forged 2.1 to stretch it's legs... a touch more lag than the VF35, but a huge wallop as it spools up properly, whilst being very smooth too.

Dunx

 

Spot on there - I'm making 415bhp and 369lb/ft on a 321H on standard internals (although there is a splash of meth in there )

 

Hello, lunar tick, long time no hear...

LOL

dunx