tyler120706

I currently have a classic with a 2.5 sti 10 bottom end conversion well modded currently running a vf28 hybrid fmic rcm massive induction kit fpr and walbro 255 pump. This spec made 310/340 @ 1bar i was expecting more but i was told my maf sensor was maxed out hence Im getting a simtec fitted shortly

I'd like to see over 350bhp not sure on what torque that may give me But hence I'll need a bigger turbo I will be fitting another brand new walbro and some 2in headers also.

What turbo should I fit would prefer something affordable in the vf range or similar

Also what injectors would I need

bighead

iTrader: (1)

MD 321H or T from lateral Performance and 600/650cc injectors

barnshaw

iTrader: (1)

if you would accept 350 you could save a load of bucks and just go VF35 and stick with sti pinks?

tyler120706

Know of any available barnshaw ???

fingerscooby

Try the for sale section on here mate for a vf35, seen a couple lately , also try the vf34, great little turbo if you can find one.

Barru Breakers

iTrader: (1)

sc38 if have funds or VF48 if looking second hand.

on 740cc

ad uk

iTrader: (6)

I had a vf 34 spool was good and made good power to I would go with vf34 m8 good turbo get a good one for 300 quid

MartynJ

SC38 would be an awesome choice for a 2.5.

mantazini

iTrader: (25)

More likely 330-340 with vf35. Vf34 would be a better choice.

Maz

iTrader: (34)

That seems a rather low limit on power and boost. Here's a quote from Bob Rawle, taken from this thread. https://www.scoobynet.com/scoobynet-...9-classic.html

The jecs ecu in the MY99 using the maf is good for 420 bhp, I actually achieved a bit more but blew the maf regularly doing it, so as I say 420 bhp. The new age ecu's are capable of a bit more, the MY06 onwards being the best by far and you can easily surpass 500 bhp using one of those with a suitably mounted maf, the MY01 to MY05 are somewhat more limited but still far better than the MY99-00. I have mapped a number of P1/STi5-6 cars to just over 400 bhp without too much of a problem using the Jecs.

I can also now map a MY99-00 car fitted with the GDB new age maf in a suitable maf tube if anyone is interested, this component is far more reliable than the normal item, and more suitable than the Z32. Obviously it (the maf) costs a lot more but I guess you need to weigh it up against the cost of after market engine management and the risk to the engine.
That said happy to supply/install and map Simtek, Syvecs, Link, Motec or whatever speed density solutions of course.

cheers

bob

harvey

iTrader: (48)

You are not running much boost. What is the reason for this?
A good VF28 is a 330 plus bhp turbo. A good VF35 might be 340 bhp and a good VF34 350-360. We have had very good results with our TD05 20Gs. Cost effective and under stressed at 350 bhp which is also easily available from a TD05 18G.
Would it not be best to optimise what you already have because 310 bhp is not a lot of power from a VF28 if the turbo is good but a lot of them are inclined to crack on the cast housing at the penny valve.
Be very careful. What are you proposing here. 2" headers on your car would be a disaster.

tyler120706

Thanks for that harvey

The boost
I was told when it was mapped that my maf was maxed out at this power hence the 310 bhp

The turbo
I know a vf 28 will do more do the bearings are getting noisey so thought it was time to change up.

Headers
Thanks for the info I'll not bother fitting them

tyler120706

Bob

So is it possible to change to maf up for something else that I'll take more stress as posted I have to change the turbo up it's about dead to be fair what sort of figures would u expect from my spec

I would like to keep the ecutek for now as Ive just bought a 6 speed conversion to make sure I don't break any gearboxes on my quest

harvey

iTrader: (48)

No way should your MAF be maxed out at 310 bhp and if it is, unlikely a competant mapper can rescale it or advise on a replacement. If you plan to go to a Simtek/Alkatek at some point in the future, that would run with no MAF Sensor which to me is a good thing and the sooner you do this the better.
On a roller bearing turbo particularly which is what the VF28 and VF34 are, it is normal to hear the turbo spinning down when you shut the engine down. As I said I would be disappointed not to get 330 bhp on your spec from a VF28 but would need to know more or see the vehicle to give best advice. Similarly, it will only take a competant experienced person a short while, under an hour to assess the condition of the existing turbo.
I am not clear as to what you were proposing on headers but choice of headers and uppipe is critical for optimum performance for YOUR spec. This is usually decided by the turbo in use I will give you any help I can on this when there is more information.
Where are you located?

If you have a 99-00 car then you should not break the TY754 five speed gearbox with the mods you propose. I have done numerous drag starts and run over 500 bhp on these so used intelligently the TY754 is far more durable than the Scooby myths on here would have you believe. The TY752 boxes in M/Y 98 and prior have less rigid casings and lesspower/torque tollerant.

OOPS! Please note I am on holiday 19 June for a couple of weeks.

tyler120706

Harvey can u pm me you number and I can explai. Better to you what's happening at the mo in greater detail

tyler120706

So even though mine car has a 2.5 sti 10 bottom end the maf is still capable of alot more ??

TonyBurns

iTrader: (3)

Most dont even think about changing the maf till way past 350bhp, yet its the rest of the car you need to worry about, the 2.5 produces more torque than the 2ltr, your 5 speed isnt that strong (there are pictures on here of a standard 215bhp uk ty754 thats stripped 3rd!) and its not uncommon for it to happen either, its the killer to your car.
Also, what year is your car based upon?

Tony

tyler120706

Mine is a my 00 x reg classic pal spec is in the orginal post pal

harvey

iTrader: (48)

There are plenty cars running 400 bhp plus and still on the MAF sensor.
I think you need to speak to a competent reliable mapper who will give you unbiased advice without regard to making a few pounds out of you. In the event you want to go aftermarket and delte the MAF sensor have a look at the Alcatek system which represents good value for money.
Tony : One swallow does not make a Summer. Sure people can break TY754s especially if they drive like boy racers and are rough on their transmission but the TY754 is a big improvement over the TY752 and a stronger box altogether but not as good as a six speed. Well capable of a long way past 400 bhp. I and many others have driven TY754s reliably, with many drag starts and more than 500 bhp without breaking anything. I would not regard the TY754 as the achilles heel on any 99/00 Impreza. I also know that the TY754 VB Jap box breaks less often than the TY754 VN UK and European box but both are relatively strong and capable of running medium tuned cars.
It was a TY754 in my STi 6 Wagon when I won Scooby Shooutout.
I have a TY754 on my WRX Wagon, in place of the 752 that I broke around 350 bhp. That car is around 450 bhp on a GT30 turbo.
The 754 box out of the STi 6 Wagon was in full working order when it was taken out and put in to my blue 97 STi 3 Wagon where it did many thousands of miles and was still in good working order when it was removed and sold when I fitted a UK six speed.

Telephone contact details sent.

tyler120706

I've taken it today to a mapper I trust for a couple of pulls and a data logging session who tells me the maf is nowhere near maxed out but also informed me that the car is running very very rich and that's if setup properly that it's got alot more to give the 1 bar it has is not doing anything for it. But there's no det or knock on the motor it sounds great but hasn't been mapped to its potential possibility of just a generic map has be used

MattyB1983

iTrader: (51)

My VF28 made 342 at 1.5 bar boost. Great little turbo..

Get the car over to a decent mapper and let them work their magic.