scatty

iTrader: (1)

im having a dilema at the moment...

dont know what i need to do to get more power...i have a jdm twinscroll which has been mapped by jgm and is producing 333/340....what would i need to gain more power....i have the k and n induction kit,uprated fuel pump etc.....

just dunno what to do next.....


or should i be happy with that and get some coilovers fitted....


any advice please.....

Shaun

How much have you got to spend..... I could tell you everything from next to nothing to a monster killer!

scatty

iTrader: (1)

ha ha, i like you style...say £2k tops.....

Shaun

Personally I would ditch the K&N Induction kit.... on OE twin scrolls they are a no no. They enable compressor surge which is not good. For what little you gain at the top end, it is not worth the holding back of boost to get rid of it, or the surge risk to the turbo by not holding back the low down boost.

Assuming you have a 3" exhaust system, you are about there..... but dyno's normally show 350-360bhp for this level of tune. If you have not already, it would be worth getting a 1.2bar actuator to enable more boost to be held, to get the power up.

What EXACTLY have you got on the car from OE?

dougwrx

A 1.2 bar actuater will have no benifit at all, as these turbos do not hold boost regardless of actuater size. Full exhaust, headers and panel filter with good mapping should see 370/380 with matching torque, maybe less torque on vf37.

Cheers Dougie

scatty

iTrader: (1)

its got a vortex zorst and full decat, along with said k and n induction.....
everything else is as when she was born...

Shaun

That's strange.... as both Bob Rawle (BR Developments) tested this and so did myself with Litchfield Imports and Powerstation and we found a decent actuator did. You try getting 1.4bar at the redline without one!!

You certainly won't see a REAL 370/380bhp out of this stage of tune... unless you are using dodgy rollers.... or high octane fuel! I only just got those figures with a hybrid twinscroll turbo fitted.

Shaun

What boost are you running... peak and held?

scatty

iTrader: (1)

crikey...you are getting technical with me now......1.5

dougwrx

Im sure that Richard Bulmer got near 400 bhp with Rob North's spec c if i recall but I do know that Edmy my mapper has got 384bhp at 1.75bar on that spec with a standard actuater.

The graph of the car my mapper mapped is in this thread

https://www.scoobynet.com/scoobynet-...ock-turbo.html

Cheers Dougie

Jolly Green Monster

iTrader: (4)

where did the 333/340 come from? if that was my road dyno figure then I must have given an explaination for it being lower than I would expect?
They suffer from heat to tmic a fair bit.. so if dyno'd the fan needs to be very good.

Agree the actuator does help a little

Simon

Shaun

OK... Richard Bulmer maybe a genius (I know), but even he can't change the laws of physics, unless that was on race fuel!

As for 384bhp @ 1.75bar. Running that peak boost for peak torque is no problem.... but running 1.75bar at peak power, you have no chance on a VF37. This is what you are suggesting. As for the power reading..... I can not account for inaccuracy of a given dyno run. If you think I am talking ****, then look at the compressor map for a VF37.

The car for that graph..... I hope that was not a Newage engine with AVCS, as it is as flat as a witches tit down low. Twin scrolls on AVCS are far more responsive than that down low.

Believe me... I completed loads of proper testing on the OE twinscrolls four years ago, and on various dynos to cross reference figures.

Scatty,
As has been suggested.... the lower figures could be down to inlet temps. You should be seeing around 350+bhp with your mods. Complete a run again on a good dyno set-up and you should see the figures increase.

A.D.Edmundson

That car was on vpower....Peak boost 1.75 and then tails off cant remember what to, theres been a few more since...

I dont think pete @ prosport wouldnt be too happy saying his dyno is inaccurate....also i have used numerous dynos with the same vehicles including prosport and all have been within 5-10bhp.

How many cars have you mapped shaun???

Ask mikee what he has just achieved with the vf37, i think you ll find your talking ****.

A.D.Edmundson

VF22

This turbo has the highest output potential of all of the IHI VF series turbos and is the best choice for those who are looking for loads of top end power. The top end power however, does not come without a cost. The VF22 spools significantly slower than the rest of the IHI models due to the larger P20 exhaust housing and is much less suited for daily driving than some of the other models. Although the largest VF series turbo, the VF22 is not quite optimal for stroked engines or those who wish to run more than 20PSI of boost.

VF23

This turbo is considered a great all-around turbo. Like the VF22 it utilizes the largest P20 exhaust housing. This housing is mated with a smaller compressor housing of the of the VF24. This turbo is considered optimal in applications with range from mild to slightly wild. It does not have the same top end power of the VF22, but spools up significantly quicker.

VF24

This turbo shares its compressor housing with the VF23 however, this housing is mated with a smaller (P18) exhaust side. The smaller characteristics of this turbo allow it to provide ample bottom end power and quick spool. This turbo is very popular for Imprezas with automatic transmissions and Group N rally cars.

VF28

This turbo came standard on the STi Version 5. In terms of overall size, it is smaller than the VF22, VF30 and VF34, and about same size as the VF23.

VF29

This Turbo is nearly identical to the VF24, with the same compressor and exhaust housings. However the compressor wheel in the VF29 is has been changed slightly. The changes made to the compressor wheel in this model are generally viewed as improvements, and as such this unit is typically chosen over the VF24.

VF30

The VF30 is commonly considered the best bang for the buck turbo in the IHI VF series line. A relatively new model the VF30 features the same exhaust housing as the VF24 but a larger compressor side similar to the VF22. The combination of these two parts results in increased output potential without the lag associated with the VF22. Although it doesn't offer the top end supremacy of the VF22, the VF30 is a great compromise between these unit and the quicker spooling models.

VF34

The VF34 is nearly identical to the VF30, with the same exhaust housing and compressor. However the VF34 goes back to the ball bearing design, and in doing so achieves full boost approximately 500RPM sooner than the comparable VF30. The VF34 is the most recent IHI design and as such costs slightly more than its counterpart. Top end performance and maximum output are identical to the 30.

VF35

VF35 The VF35 has identical internals as the VF30 and it uses divided thrust bearings. However, the exhaust housing is a P15 which means this turbo will have fantastic spool characteristics. This turbo is standard on the new WRX Type RA. LIMITED SUPPLY.

more info





VF36
Roller bearing version of the twin scroll VF37, also has a titanium turbine and shaft for even quicker spool. Same compressor housing as VF30/34, however twin scroll P25 exhaust housing provides slightly better top end output due to reduced exhaust pulse interference. This turbo is good for 400HP and used on JDM STI Spec C from 2003 onwards.

VF37 (thrust bearing)
Enter the age of twin scroll IHI turbos. Same compressor housing as VF30/34, however has a new twin scroll P25 exhaust housing that provides slightly better top end output due to reduced exhaust pulse interference. Twin scroll also provides better spool up for improved low down response over the VF30/34. This turbo is good for 400HP and used on JDM STI from 2003 onwards.

VF38
Twin scroll turbo with titanium turbine and shaft. Smaller compressor housing than VF36/VF37 provides tremendous spool up capabilities but less top end than VF36/37. The spool capabilities of this turbo are demonstrated on the JDM Legacy GT, which reaches peak torque at 2400RPM.

VF39
Single scroll turbo used on USDM STI and latest 2.5L STIs released internationally. Smaller than VF30/VF34.

VF42
Exclusive turbo to the S203/S204 models, this features a twin scroll design with a slightly larger compressor than the VF36/37 turbos and different turbine design (more blades). The VF42 is a roller-bearing turbo and is likely of similar size to the VF22 turbo, but with twin scroll exhaust housing for faster spool and superior top end performance due to reduced exhaust pulse interference.

Shaun

A.D.Edmundson,
Get a compressor map up then.... once you have done that, then speak to someone like AET Turbos or Turbo Dynamics and ask them how much a VF36/37 will flow.

I did OE and Hyrbid twin scrolls to death 3yrs ago, on a six month development project and completed hours and hours of development work with Litchfield Imports, Powerstation and Turbo Dynamics. I documented all these articles on ScoobyNet, but unfortunately they seemed to have dissappeared since Simon and I sold the site to Internet Brands. If I know anything in life, I sure for **** know about the JDM Newage Engine and it's twinscroll capabilities.

You may well tune engines as a professional business, but I guess I was working with companies testing twin scroll stuff on Scoobs, before you even knew what a Spec C was.

The last I heard Mikee was running 370bhp and that was on E85..... totally irrelveant in this conversation, as we are discussing VPower.

Shaun

That is TOTALLY laughable and simply untrue! OE twin scrolls run out of puff, drastically, at the top end....... everyone knows that!

Get a compressor map up!

dougwrx

It maybe too late but before you get all up your own **** speak to Richard as I am sure he has got near 400 power on vpower, and as for mikkee his dyno print from saturday should be put up on monday and will make for interesting reading


Cheers Dougie

A.D.Edmundson

i think all them bananas are going to your head.

Shaun

I know exactly the size of compressor housing and core required to reach a solid 400bhp on VPower with a twin scroll set-up..... and it is a shedload bigger than a VF36/37 core and cover.

Mikee's results are totally irrelevant.... we are talking straight VPower. If E85 makes so little difference at this level, then why the hell has he chosen to use it. I could make a fairly decent increase in power by using poxy NF three years ago, at this level of tuning...... let along something as good as E85! I know, because I tested additives as well.

So, well done on your amazing results.... perhaps you should have a chat with Sir Issac Newton, as you have clearly re-written the laws of physics.

Doug,
Remember, he was the one who said I was talking **** first! Perhaps I am not the only one with an anus problem!

A.D.Edmundson

As it cheaper, it smells nice and as tesco states ''every little helps''

Speak to your tuner.....i remember him telling me he made around 12bhp extra on e85 on the last one, and the few i have done i have only seen 18bhp tops.

im off to see sir issac....

love you

apac

iTrader: (2)

Just to get things back on track, I'm on a very similar quest to you Scatty. I'm running 353bhp/385ftlbs on the road mapped by Bob Rawle. Miltek sports cat system, panel filter change and 3 port solenoid (2003 twin scroll Spec C). I'm trying to squeeze a little more out of the turbo and intake and a cheap move forward seems to be an actuator that will 'crack' the wastegate at 1 bar (as told by B.R.). Am also thinking of getting a Hybrid front mount intercooler to keep charge temps cool. With these two links in the chain i was hoping to get a bit more top end power as the VF36 on my Speccie dies off at 6.5k rpm - which is a bit annoying on the track. - But i'm not sure whether to go through with it or go another route.............................

The other route could be waiting for Litchfield to put their new twinscroll turbo on the shelf and then along with uprating your injectors you could see 400bhp. This is the very dilema i am currently having.
Scatty: 2K will get you the new litchfield turbo and uprated injectors -'just'!! then a couple a hundred more for the remap, and pray that your clutch doesn't start slipping,,- lol ,,, and your charge temps stay safe!!

Jolly Green Monster

iTrader: (4)

Unusual but I agree with you Shaun.. there seems to be a few inflated and unrealistic figures spouted for the OE twinscrolls. .they are fantastic but not 400bhp turbo.

Heat was highlighted recently by Scoobytc's car making 338 but tmic was very hot as it took a fair few runs to get the boost where I wanted it when mapped on the dyno and my trusted road dyno showed 25bhp more than that and he went back on the same dyno later in the same week without the number of runs before hand and it made 350 something.

Simon

A.D.Edmundson

To be honest im not really interested what people think, its there in black and white....unless you are saying petes dyno is wrong or im a liar then so be it.

Im also not confessing to make a solid 400, the graph clearly shows 384bhp, its obvious the torque figure is correct but in some mysterious way the bhp isnt??!!

Like i said previous just because others cant do it doesnt mean i cant. i.e the americans and australians are way in front of us and have been doing things for years that we still cant do!!! just because we cant do what they can, doesnt mean it cant be done.

I dont want to get into a massive argument were ''my dads bigger than yours'' and i will say no more on the matter.

Back on topic to help scatty.

ant...

Shaun

The most we ever achieved was circa 365bhp on the old Optimax and that was running 1.7bar peak and circa 1.4bar held at peak power. You are virtually screaming the nads off the turbo to get that. Inlet temps are quite critical, and you will end up heating the air. We did a fair bit of charge temp testing for these conclusions..... more boost does not always redeem more power, when the turbo is so small. The later (mine was a MY03) engines (MY05>) seemed to make power easier though.

Several HKS twinscroll turbos were developed some years back, that were reputed to achieve 400bhp. It was a struggle when we tested these and they were not great in the spool department. A lot of these were sold on the back of US power graphs..... US power graphs do not seem to tie up with what we ever achieve in the UK, so beware.

Of course a FMIC would help whilst on track for instance, but it is always better to find a turbo that will flow enough for the power you wish, within it's efficiency range and to be quite honest, the standard STI8 top mount is a great piece of kit. With the right turbo you will be fine on the charge side (certainly for road use) well up to and just beyond 450bhp. I know AndyF has seen well over this figure.

The dieing off at 6.5k and beyond is the unfortunate downside of the OE twinscroll.

The new Litchfield twinscroll turbo's meet your remit. I have driven a car with one on and it felt great (one of their development mules). Either hang on for the general release of this, or go the single scroll route.

bluenose172

iTrader: (2)

A.D., assuming a stock MAF scaling/intake, what G/S are you flowing in your logs with over 380bhp?

bluenose172

iTrader: (2)

BTW - if anyone has a VF36/37 flow map, I'd like to see it. I didn't think IHI released their maps.

apac

iTrader: (2)

Thanks Shaun, they are really reasuring words. I've read all the scoobynet MY03 Spec C project articles and all the stages n trials the car went through. It's great to read about a project car in such detail which is the same as the one i own. Pity the project couldn't have continued with a Litchfield turbo on it!
As for the litchfield Twinscroll - i hope this will see boost up to and beyond the red line!

In your opinion then, just uprating injectors before fitment of this long awaited turbo will do the trick?

cheers
Andrew

A.D.Edmundson

No MAF, Hydra with MAP.

Shaun

Hi Andrew,
I still may well test the largest twinscroll turbo from Litchfield Imports.... just to see how it performs. So you may well see it documented in the near future on my current Project Thread. However, I doubt it will hold till the redline..... my GT30 (3076 based) won't do that! You would need some hefty core to do that on a 8000+ JDM rev limit.

Assuming you are looking at the "baby" version for 400bhp.... yes, injectors and I am 99% sure that this turbo does not require manifold spacers. Stick with the OE Spec C inlet pipe and airbox with uprated panel filter. However, depending on the size of the inlet on the cover, you may need a larger inlet pipe. Stock TMIC. 3 port boost solenoid, if you don't already have one. Fuel pump should be fine, as I ran around 470bhp on the OE Spec C pump and 800cc injectors, before going to external pumps etc. No problems with pressure at all, although I would not suggest that anyone would push the OE pump this far. Only other thing is the remap.... ECUTEK is fine and dandy at this level.

scatty

iTrader: (1)

this was from scoobyworlds rollers....it was fairly warm and you know how hot and stuffy the room is.....your road dyno said roughly 350/350......

still like to know what you would suggest for more power simon....as suggested, it looks like it will have to be the litchfield new turbo