So what can be done next... Hawkeye WRX
 

Hi everyone

I've had my car for well over a year now and touch wood (of it getting stolen and recovered) it's never missed a beat.

I've done the usual mods to it, including:

Miltek 3" system
VF34 turbo
Ecutek
Coilovers (SuperStreets)
Brembo upgrade
OZ Ultraleggra wheels
STI spoiler
Front splitter
etc etc

Car is running a safe and stable 350bhp/400ft.lb.
Not to appear greedy or anything, I do feel like the top end is lacking. I have done the odd track day and the turbo soon seems to run out of grunt (though it does spool up very low). I'm running 1.5 bar at present.

I'm very conscious of the internals going on me, but realistically what could be done next? Would it be a forged build, would it be a front mount ... looking for suggestions with pros and cons please.

Not sure what people have done with the WRX's beyond 350bhp - anyone :idea::)

Cheeeeeeers

Lee

Ive done very similar and have been planing the same thing,

Although I believe the following:

To go higher, need to put a 6 speed and related clutch into it...

Then can look at internals e.g pistons.

Miltek Sports cat/decat?

Walbro, FMIC and Bigger turbo.

Adam

Bez blew his up...

No - LOL

dunx

P.S. A quick hone some pistons and rods, uprated oil pump and yet another turbo and you're good to go for 500 bhp if you fit a six speed

done a few with 18g or 20g on.

gearbox won't thank you so 6speed ideal route.

Simon

1.5 bar may be stressing the wrx 2.5 engine a bit, might be worth looking at forged internals anyway just for longevity

A fmic is a great idea if taking on track, I would also consider fitting an oil catch can as the breathers on the heads chuck out quite a lot and that will be going into the intake and reducing the effective octane of the fuel (and possibly causing det).

You are very close to the limit of the engine / box but there are lots of little things that can be done to improve the cooling of the air flow into the engine which without adding much power individually they will help and they will especially help engine safety.

A forged build is definitely a good plan if you are thinking of around 400bhp or at least budget for one when needed...

Gearbox will be fine if you are reasonably gentle with it.

Aside from that changing turbo would need to be to a 321T or similar so as to make a worthwhile difference but would def need forged build then.

Lee has already had the box out...

dunx

Got a good PM last night, apparently API do a drive in drive out for £2,5k for 6 speed upgrade ...

Plus clutch ?

Cynical dunx

P.S. Given your track use you'd be better off with a DCCD box ?

Some drivers are harder than others on the box. Generally the box on your car is good to 400/400 driven sensibly and that is beyond the ability of your current engine which is close to where they will break ringlands.
If you have no plans to go forged fit a set of ported headers with matched uppipe and that will give you a noticable benefit and make the engine more efficient. Your TMIC is approaching the limit of what is sensible so if you are going any further or want to improve what you already have you need an efficient FMIC.
Going internal you need forged pistons and if you want to go beyond 430-450 bhp then do the rods at the same time but you can probably get a bit more out of the car by improving what you already have. If you are going internal go for a set of GT2 Spec tubular headers with special uppipe on the assumption that you are also going to do turbo and injectors along with FMIC and aiming for 450 plus bhp. However, you are in to major expenditure to go internal because it opens up new horizons.

PS: Fit some vent to atmosphere breathers for the crank case and both cam covers or as Duncan suggests catch can.
Important. Keep away from the rev limit. Can be fatal on these engines.

Thanks Simon. I'm likely to look at the 321T route afterall, with a 6 speed box. Just deciding over DCCD and non-DCCD now. Then the expense can really start...!

I guess (with a new map) I could run the current setup with the 6 speed box and new clutch, rods and pistons and maybe, as advised below other little bits til I could afford to go FMIC and turbo etc.

Would I be able to push the VF34 anymore with harder box/clutch and internals, or has the top mount reached it's limit here anyway?

Correct - clutch on top. I don't want anything too aggressive as I do like *some* refinement and smoothness. I'm yet to be told *why* the DCCD box would suit me better and how it would benefit the odd trackday use. It's going to be no time attack car, would I really see the benefit....and is it worth the extra expense?

Harvey

Is it just the WRX engine or the 2.5's in general that suffer from weaknesses?
I always warm the car in and never bounce off the limiters - I shift up just as the boost starts to drop off full and keep it within the gear.

Is it worth doing the catch can / oil cooler on the current setup anyway, or am I better off getting the box, new block (potentially) with forged pistons, rods and breathers...? then moving towards the next step?


BEZ - what did you do to yours?

Thanks Duncan - answered a few of my questions there!

Again, by adding the FMIC the 'plumbing' will obviously change quite a bit. Am I better off adding the swirl pot / cooler and potentially breathers on now then?

I tend to be steady with the gearbox and the clutch - I'm very conscious that being too hard on either one could be devastating to my bank balance at present!

I would consider the fmic and catch can essential safety items if you are going to be going on track a little more often (but not a track car) as these will stabilise the temperatures of the air going into the engine (preventing det) and stabilise the octane of the fuel going in (again preventing det). You will add more power by going FMIC route by optimising the map for the fmic without pushing the turbo any harder as it may not have much more to give anyway. This will be because the air going in to the engine will be cooler and therefore more dense. I would fully expect another 20 bhp just from those two mods without running any more boost.

Personally I would leave it there. 370bhp is more than enough for a track day and for great fun on the road. If anything it is more fun that 500bhp.

£2.5k is a lot of money even though that is a pretty good deal but tbh I would keep that money aside for engine rebuild if it does go or for the box if that doesnt last rather than spending it first.

You are running 1.5 bar boost at the moment (guessing that is peak boost) and that it is tailing off at the top end. This is simply a physics thing in that the turbo isnt big enough to hold that pressure to the top end on a 2.5. Not knowing what your map looks like, but just going from the expression that you feel it is tailing off at the top end, it may be that the map has been kept reasonably sensible at the top end because of the TMIC and the fact that you have to account for the inefficiencies of that when completing a map. Going the FMIC route will give more at the top end and will help no end IMO. Harvey's hybrid FMIC works great and would be a good low cost choice.

Much as Duncan says. Oil breathers for sure.
FMIC if you want to go any further or want to track.
2.5 WRX pistons have ringland issues.
In routine spirited driving shift up the box long before the red line.
NEVER HIT THE REV LIMITER.
If you are not going any further (ie. internal) ported headers and matched uppipe.
If you are going internal which is a lot of money tubular headers and special uppipe at which point you will need bigger turbo, bigger injectors.

DCCD is a better option due to adjustable torque bias, also only pre-05 STI's have non-DCCD boxes and they will generally be getting a bit "old"...

I have one in my garage, but there's a reason I took it out, 50:50 fixed power split.

dunx

P.S. Bez killed his chasing Bigarf round Cadwell, but it did the business for a very long time, and was soundly thrashed everywhere... :luxhello:

The Hybrid FMIC is not a straight forward fit on the Hawkeye, had to get a couple of pipes custom made for mine.

Harvey

Do you sell a complete FMIC kit for the Hawkeye WRX?

Hmmmm have to say very interesting reading.........think I may have just figured a way to spend some money......:norty:

There's always something to spend on - a full tank of fuel and a good run out usually ticks the boxes :)

Harvey/Duncan, I've sent you both PM's :)

You ain't wrong there..........:thumb:

Yep, agreed, but it did work very well :cool:

Lee - yhpm back :thumb:

Emz - an FMIC would work very well on yours ;)

Oh Duncan, what are you going to me............ lol, what about Oil catch and all that???

Hmmmm me think another chat with Harvey needed......:norty:

All PMs up to date as far as I know.

Emma - will chat to you during the week and see what is best for yours :)

Hi Lee: I think I dealt with this by PM.
I have a Hybrid kit here for Hawkeye but it is very expensive and we have not fitted one yet but for the last 2 months I have been looking for a guinea pig car (Hawkeye) that we can fit a kit to and because it would be a guinea pig car we would need it here for 2 or 3 days so that if we have to fabricate anything we are not under pressure.
Subject to hearing back from the guy concerned we possibly have one to do at the beginning of February at which time a Hybrid can produce production kits but the deal for fitting the first one is that we would supply the kit for £395 and fit for £185 which is exactly the deal for GDB models 01-05. Thereafter Hawkeye kits would probably be priced around £575 but I am prepared to do the above prices on the first one to allow us to complete the development work.
If this is of interest to you please let me know but I have to give Martin C until Monday evening to confirm or reject the offer already made to him.
To get in touch harveysmith1@btopenworld.com

Lee, it's probably worth mentioning that you're not going to get much of a top end on the 2.5 with the VF34 or anything of a comparable size. They can't flow enough air at high rpm. What they will give you is a lovely low down shove and a good mid range which -as I'm sure you've realised - is great for road driving!

If you want substantially more ompf, then you're going to have to address the turbo, and that means sorting out the engine internals. The Hawk's pistons cannot take anymore than you're currently subjecting them to. At this point the costs become substantial.

My PPP hawk STi is at APi for a forged 2.5 build to support a SC46 turbo and.....well, lets just say the costs run into 5 figures! Hopefully I'll be able to recoup some of it selling the std parts on here.

I would suggest that the modifications advocated by Duncan and Harvey are the way to go for you; more about optimising what you've got and making it track safe than getting substantially more. If David at APi were on this thread, I reckon he'd also advocate you get a baffled sump and an oil cooler for your Hawk, especially if using it on track.

Best,

Ns04

Thanks Harvey

I've dropped you a PM and and an email.

I'm more concerned about maintaining the temps and longevity of the engine. Of course more is in the pipeline and I certainly can't afford 5 figured for a forged build :( but bits at a time to make it more suitable for pushing harder than driving almost waiting for it to pop.

The front mount and oil cooler / catch can are what I'm looking at immediately with some internal work later. Again, we'll see how things progress :)

Fit an oil temp guage first. It will confirm you actually need an oil cooler and is a very wise addition to any track car. A quality oil temp and pressure combined ie single 52mm guage is under £100.
I will get to your e-mail later.
Thanks.