Sub-Subaru

I have a standard 2004 WRX Impreza that has now covered 102,000. I want to do some mods to get more power out of it. I have read posts on here and replies to some of my own threads and so I think what I want to mod is the following

Bigger turbo
Sti TMIC
Sti injectors
Walbro fuel pump
Upgraded spark plugs
Prodrive Sports Cat exhaust
Remap

My question is which turbo? I have read that the VF35 or VF34 would be good for this kind of setup but I can't work out which one is best. I use the car as a daily driver for B roads, so I want the spool up to be good. One of my concerns is hearing about boost surge on the VF35. I don't really know what this is but imagine it is bad and I don't want to buy something that is going to cause problems and damage to the car.

Can you give me some opinions and advice on the above. Also I have heard about other things like boost solenoids etc, is there anything else on the above setup that is advisable or necessary?

thanks

beliblisk

iTrader: (16)

Vf30,vf34,vf35 are similar capacity turbos.Vf34 is ball bearing and it spools a bit better.
All are good for at least 330 + bhp with the supporting mods you listed.

I had vf35 in my gc 8 340/310 and it was goid setup for B roads.

Vf30 and 35 sell fir around 300-350£,vf 34 is 400-450£.

Also consider to spend 1,5 k£ on suspension and brakes

Sub-Subaru

From what I was reading everywhere it seemed as if the VF35 spooled a fraction quicker than the VF34. Or is it that it spools later but better?

Also can you explain to me what this boost surge issue is and whether that would be a problem for the other turbos like the VF34.

I just want to make sure that I get this right first time, I don't want to be swapping turbos again in a few months.

It almost seems like it is better to just buy an Sti and do a couple of mods that it is to do a WRX if the engine is modified, suspension, brakes etc. Is it cost effective in the end to mod a WRX?

Tidgy

differet turbo design, vf35 has smaller housing to aid spool, where as 34 is roller bearing so has spool and better top end, spool wise not much in it, 34 will prb give aroudn 10bhp more at top end on right setup.

could always look at an sc36, better spool and top end than both the 34/35

beliblisk

iTrader: (16)

Yes it is better(cheaper) to just buy stage1(or better) STI.
Brakes,suspension,engine capability,gearbox,IC,turbo,injectors,etc.... all those things will need to be improved on wrx to handle 350+ bhp.......or it will be just runing on borrowed time:P

Sub-Subaru

So would you say generally the 34 is better over the 35? I'm changing from the standard TD04, would you say I'm going to notice a big shock in delayed spool?

Another turbo, but I haven't heard of those ones. I don't know how people learn about all these different setups and what is best for their car.

What cars did the SC36 come on I haven't seen any advertised or recommended before.

I really am going to continue to run stock internals and don't want to wreck it so am only heading for 300-340bhp max. I don't really want to start spending mega bucks on suspension and brakes to be honest. I just think that insurance and cost of buying an Sti right now along with the hassle of selling my WRX is going to be pricey. Then at a later date maybe an Sti. I just think if I don't do the mods now then it will be too late.

Tidgy

not from a car mate, after market, theres a 1000 page thread on em in the traders section, scoobyclinics billet turbos best performing on the market at the minute.

Sub-Subaru

Had a look at the SC36 don't think that I can justify the £950 cost on this car really. If this was an Sti and mint I would.

My thinking was that I really need my car to be quicker or buy something quicker. It seems like something with the same year in Sti is going to cost around £7000 so that isn't really an option.

I was going to just do the exhaust, filter, plugs, and then map it but I really want to get near the 300bhp mark so thought that it is worth just paying extra on top of this for a bigger turbo, injectors, intercooler and fuel pump.

If you were me and you wanted to get a bigger turbo to hit 300-340 max as a daily driver and to do B roads and to keep costs down, what would you recommend. I would like to have really early spool up.

beliblisk

iTrader: (16)

If you are on budget then just go to stage 1,with your td04 and you will get to 280bhp with awesome spool.Or add this to reach 300 with unmatched spool:

http://www.ebay.com/itm/Turbo-Compressor-Billet-Wheel-Mitsubishi-TD04L-13T-SUBARU-WRX-Forester-4G63T-/121211986307?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item1c38cc2183
Spend the rest on brembos and suspension

stealthbomber

iTrader: (3)

Sound advice imo

Sub-Subaru

I dunno now I'm really not sure. I just think that after spending the money on the actual remap and exhaust I've already spent so much it would be nice to spend a little more and get more power.

My power cap is due to running the stock WRX engine and so if I can go up to what that can handle then I will. I have never seen any talk of changing the compressor wheel in the TD04, how come more people don't do that.

I think though that keeping the stock TD04 as it is is not an option.

beliblisk

iTrader: (16)

Its your call but impreza wrx with 280 bhp and sorted suspension&brakes if much better than one with 300 and stock suspension and brakes

Imagine that you streck your self to maximum with spending to make 340 bhp and then your gearbox decides to blow up (when tuning impreza with 5 speed you must have spare funds for gearbox upgrade).

Either go stage 1 or get an STI.


As for billet wheel.I dont know why more people dont do that. They tend to rather pay one zero more and get billet turbo from one of the tuners.I will do vf43 billet&ported for next mapping session in the spring.

Sub-Subaru

When I was originally looking at getting my car mapped I thought 280bhp would be great. Now that I have driven it more and more I really now want to get more power than that if I can. I'd rather go bigger now and gradually do the rest as mapping a second time at a later date will either be constly or not worth it with a high mileage car I reckon...

I understand what you are saying about better suspension and brakes and in an ideal world I would replace that as well. However, I don't really like braking mega hard and find the suspension okay at the moment. Why is it that the suspension needs upgrading?

I think that once I did a stage 1 and got 280 I'll have wished I spent another 500 for the extra bhp that I could get from a slightly bigger turbo and injectors etc. I guess the biggest concern for me is that I don't want to loose quick spool as overtaking on B roads you need to be able to go when needed. I just want to be able to do quick 0-60 and overtaking stuff.

When I started looking at this the VF35 people said it is just off the pace of the TD04 for quick spooling. However, this boost surge people are talking about and cracked housing concerns me.

How people make decisions with all the different bits and options out there I'm not sure.

Berks-Jack

iTrader: (10)

I'll have a vf34 and sti tmic with undertray for sale in the next week. Been running the turbo on my blob wrx but returning it to standard to sell it.

Let me know if you are interested.

beliblisk

iTrader: (16)

Crack in housing is almost OEM thing when it coms to vf series.......but it still performs normally so i wouldnt worry to much

Sub-Subaru

Is this boost surge thing an issue? Is there any way to avoid it e.g. porting the turbo? Also if you fitted a billet wheel to a VF35 would that reduce the spool up time?

My issue with keeping the TD04 is that the punch from it just isn't enough, I don't know if this will improve dramatically after a map.

Jack I would be interested in knowing the details and price of both please.

beliblisk

iTrader: (16)

Billet wheel is lighter so it will reduce spool time,but not drastically.
You can do with vf35 what i am doing with vf43 (billet wheel,port&polish) i imagine it will be great turbo.

BTW i never had any surge issues with vf35......i guess its down to mapping.

......your gearbox might not like that:P