APS SR40 Turbo,Whats the Verdict
 

Does anybody have any experience of this turbo and if so what do you think.

I'm thinking of fitting one to a STI7 to make 400BHP, according to the web site its good for 440bhp.

What is the spool up like, lag etc how would it compare to a TD05/06.

The other option is a PE1818F which is based in a IHI turbo so not as keen on this one.

Any opinions welcome, I would rather find out now rather than buying one fitting it and then finding out its crap.

Cheers

Scott

Scott,

There are some quite lenghty threads over on the NASIOC forum. I would have a look there before spending your money on what is suggested in the threads to be an under performing turbo.

Cheers

Martin

Cheers Martin I'll have a look.

Scott

Very diplomatically put Martin.

I have completed an install on a 2000 P1 using a SR40, the owner was sure he wanted to use that turbo even after me suggesting it wont produce the goods.
Ecutek Remap
Hybrid FMIC from Harvey
Filter
Full decat
740cc inj

396hp @ 1.7bar near as dammit...

Rob

I would suspect that with headers as well it would get there. :) It will produce 400 HP as seen on a few cars but needs a lot of supporting mods. :)

I've had a look on the NASIOC forums and there seems to be mixed opinion on the turbo, the biggest grip seems to be the lag which is one of the main reasons for going off the PE 1818 turbo.

Is this turbo any better or any worse than a TD05/06 20g

The mods that I'll be running with it are;

OBX equal length headers and uppipe,
3" full decat exhaust,
Perrin induction pipe
APS CAK filter
Hyperflow TMIC
HKS SSQV dump valve
3port boost solenoid
Helix 5 blade paddle clutch
Lightweight flywheel??? (if I can find one)
Standard STI7 injectors
and a TEK3 map to suit

I know that I might be struggling to wring 400bhp out of either the TD05 of the SR40 and I don't want to be running excessive boost pressure as this is my day to day car so I need reliability as well.

I had already bought a TD05/06 to do the job but thats a different story, so I'm back on the market for a turbo.

Any more thought would be appreciated.

Scott

smallish garrett hybrid from lateral would be my choice.. something similar to the MD321 iirc.

It depends what you are trying to achieve and what is important to you.
In my experience the TD05-06 20G is pretty rugged with acceptable all round characteristics and above all it represents good performance for money. However, 400 bhp in day to day trim is at the top end of its performance envelope.
Explain to Andy F what you are looking for and I am sure he will give you the best advice he can coupled to a cost effective solution from his Deadbolt range.

Scot, you seem to have all the neccesary parts there "in theory" to get 400 HP from an SR40. Except you will struggle on standard STi pink injectors. I would recommend upgrading to 650cc injectors. These are in stock if you need them. Remember when comparing figures from the USA to the UK that there pump gas out there is alot lower octane and so its difficult to compare apples with apples so to speak.

Here is a graph for an APS SR40 on an STi 7, similar to yours in specification but with an APS front mount rather than top mount intercooler.

http://images.fotopic.net/y87by0.jpg

Regards

Conrad

Ultimately it will be Andy who maps it, I'm trying to get everything pulled together to get Andy to Tek3 it next month the turbo is the final hurdle.

Scott

I don't recall if we discussed the options regards your "dodgy turbo" but it would be possible to convert it to a "proper" TD05-20G for much less than the price of a new one.

Andy

Hi Andy,

I don't want to do anything to the turbo until I try and resolve the matter with the guy that sold me it.

Besides as I've already paid over the odds for what it is, with the cost of converting it on top I could easily have bought a new one and that would really stick in my throat.

I'll keep you posted

Cheers

Scott

Conrad,

US 94 octane pump fuel is higher octance that 97 RON super unleaded in the UK. Most people in the US will dyno with 93 or 94 PON fuel, but that's Pump Octane Rating and is (RON+MON)/2.

Paul

Sorry just to add that the car also had headers....

Rob

OK Paul fair enough, stand corrected, didnt realise US fuel was PON and not RON.

Rob, boost seems a little high in that case to get the numbers, the G-Force car certainly wasnt running that amount of boost to get 400 :confused:

Not to worry, when I get my new WRX I am going to try an APS SR40 just to see what it can do.

Would that be the G-force car running on their own rollers ;) ;)

:)

Rob

:D Not sure which rollers the car Rob was doing was run on though and that was only 6 HP behind. We will be collating some information on the various turbos available shortly. Same car, same spec everytime, same rollers, different turbos. etc

Andy, Paul, do want to put one of your 400HP Deadbolt ones on test? Will make great information for the masses, sort out the underperformers from the genuine 400 BHP ones?

Would like to independantly test these;

Deadbolt 400 HP Turbo?
APS SR40?
TD IHI MD321?
Any others?

Yes, sure would :) Although I think the "masses" you refer to already have a fair bit of info on these turbos ;)
As long as your test is not just about peak figures but looks at the power available under the useable rpm range, after all this is what determines a fast from a not so fast car. The peak figure is really just 'pub talk'

I am currently undertaking a similar exercise, where I'm taking a 03WRX through a range of turbos, starting with the TD04 which with a slight mod is currently making 330 bhp with full boost from 2600rpm.... that makes it an uphill struggle for the TD05-16G which is next in line for testing, followed by the well proven 18g and 20g.

Andy

Yeah and you know i want it! The only problem i have is getting it fitted before i ask you to map it. Who could fit me that? lol.

Andy,

True, but it would be good to see some specific back to back testing of the "turbo's", rather than numerous set up's, using numerous unspecified fuels.

Now, is that a "real world" full boost (1bar, 1.4bar ?) at 2600rpm, with, or without the infamous left foot braking ? ;)

330bhp, fantastic result :D

Mark.

"that makes it an uphill struggle for the TD05-16G which is next in line for testing"

TD05H-16G is just so last year. Perhaps they will become cheaper :idea:

How did you manage to get 330bhp out of a TD04, I didn't think you could get close to 300 never mind 330bhp from one. But what was the slight mod?

1.4 bar, 5th gear, flat road, no brakes.

The one thing I have found is that the same car, same set up - different turbo, was that each one required significant mapping changes to achieve the turbos maximum potential. It's not as simple as just bolt one on after the other and dyno them, that could give a misleading result if for example the mapping was optimised for one particular turbo.

Andy

Scott

I use a different compressor wheel in the std housing.

Andy

Andy,

Agree, the map would need tweeking, so long as the boost level remained the same.

Mark.

So would each turbo supplier be able to optimise the map to his own turbo ;)

Turbo Shootout ? :norty:

Bob

Sounds like a plan developing here, I agree there is lots of info documented on each turbo already but I dont think its easily accessible for all. I would propose that the results would be published on our website for all to see. They would also be available to each turbo supplier.

Turbo shootout conditions.

Same car everytime,
Same fuel everytime (Optimax nothing added),
Same rolling road road everytime
Turbo supplier can have mapped tweaked or tweak it themselves in terms of fuel, ignition but boost level must be fixed @ say 1.5 bar for all turbos.

The winning turbo would be the best allround turbo, torque and how it spools not neccessarily peak horsepower as the aim is to find the best 400HP all rounder, however it must be within a 5% of the target figure ;)

Any other things we should consider?

Conrad