Engine build 400+ bhp
 

Hey guys , im new to the forum world, currently building my 2004 wrx sti engine (blob eye) the engine is ej20 (full UK), I am building the engine with strength/reliabilty in mind for running 400 plus bhp, so far iv bought for the build:
cosworth forged pistons
PEC rods with arp rod bolts
acl race bearings
arp head stud conversion
cosworth head gaskets (1.1mm)
Roger Clarke modified oil pump
cosworth cambelt with modified belt guide

the biggest worry for me so far is which turbo to go for, Iv heard the FP green turbo is good, I want to use a turbo which is bolt on (no twisted conversion) also deciding on which front mount intercooler to use and if the STI injectors are good enough when running more boost, i have the 255lph walbro pump already fitted, possible parallel fuel rail conversion may be needed?

Any help?
cheers in advance

Why bother with all the above when the standard engine will run 450Bhp all day long.

FP Green will make the power ok. Not renowned for being the most reliable of Turbo's. I'd stick with a MD321T or SC460 Billet.

MD series turbo. SC billet series. Injectors will need some headroom if your looking over 400 so allow for a set of new ones

Mmmm... I think that is a bit of a "sweeping" statement imo.

Iv heard different things on the limit of the standard internals, some say 450bhp is fine some say the pistons limit at 380bhp before you start doing damage, as im new to subaru tuning i just appreciate any help or if people had problems with certain areas when modifying, tbh i am aiming for 450 bhp but anything over 400 i will definitely be happy with.

thanks for your help guys.

If you take the OE bottom end to 450bhp you have to accept an element of risk! To state they will run at this level "all day long" is very misleading imo. Yes some do take this level and some also don't! IMO it is how you use the car and what you use it for as well as the strength of the bottom end.

If I smash a car around the track for 20,000 miles that is totally different then going down the shops for 20,000 miles. An extreme oppposite, but I assume you catch my drift.

Subaru specialist engine builders exist for one main reason.... because these engines do let go!

If you want reliability for any given remit, you may end up digging in to your pockets and it is always best to prevent rather than closing the door after the horse has bolted.

For what I currently use my car for, I wouldn't personally push it much over 400bhp.... as I certainly want as close to OE reliability as possible. The more I push it, the more risk there is that a failure will happen.

Alot of this is subjective, but you are doing the right thing by going in to this open minded.

IMO if you are looking at 400bhp and your engine is OK... go for it. If you are looking at 450bhp out of the OE bottom end, expect a problem in the future and have the cash ready incase it does. Best of both worlds and at least you're covered and prepared. :) At the end of the day you maybe alright.... but then again, maybe you won't.

As Shaun has said... If you are aiming for anything above 400, so lets 400-420 mark then I would do it on the standard STi engine. I have taken my STi (2002) to 370 odd and plan to add the final few mods to get it above the 400 mark.

However I do have keep thinking "how long will it last"... but running great right now. I do realise that I will have to build the engine at some point, but hopefully thats some way into the future.....

I appreciate your input guys, whenever iv done a project engine before i always tried to find a happy medium in which parts are essential and some which are over engineered for the application i need to use them for. I'd rather pay the money for decent parts now than paying for a short/long motor if i spat a rod out the block whilst going round the nurburgring. ( my plan when its ran in and running well) not sure what the recovery charge would be back to england from germany ? haha.

has anyone had any experience with the FMIC from japspeed ? they seem suspiciously cheap at £299, most reputable fmic's are around £700-£1500 ( i.e HKS , Perrin etc. ) but if they are well made then i wont need to pay twice or 3 times the amount for a kit iv heard of.

Ran stock engine at up to 450bhp, one of them for 4 years so far. It's been dragged, tracked and carried out plenty of road miles.
The SC46 is an amazing bolt on turbo on an STi8, easy 400+ on Vpower, stock ecu and intercooler with the correct supporting mods.

Martyn

i've got a japspeed fmic, very good quality, for 450 bhp i'd save the money as the japspeed is fine for this.

Id stick with my statement that at correctly mapped and modified newage STi can run @ 450Bhp without issue. True there is always going to be a chance when modifying ANY car that they can let go but the newage STi engine is one of the strongest out there. Simon's is running well in excess of 500Bhp on standard internals with no issues, and he doesn't drive it like miss Daisy ;)

As for FMICs you really do get what you pay for, I'd not even consider a Japspeed or similiar. I've personally got a Perrin going on my car tomorrow. Either Perrin, Hyperflow or APS would get my vote.

brilliant news tazz, i bought the japspeed de cat bellmouth downpipe and it was really well made and fitted perfectly, the thing will manufacturers like hks and blitz etc they make really high standard equipment but many underdog manufacturers can offer alternatives at really reasonable prices, just didnt want to buy cheaper bits which would go wrong a few months down the line.

Yes we have experience of them. Not a bad kit for the money and plenty effective enough up to 450bhp so far, going to push one a bit more later this week.

Martyn

http://i258.photobucket.com/albums/h...y_sti/avcr.jpg

On a newage sti engine for 20k miles on a rotated GT30

Agree with Martin going by the SC46 that was on mine! Just ask Kev (scoobyclinic), Pat Herborn or Paul Blamire how quick it spooled and pulled like a train!

Speak to Harvey for a hybrid FMIC... around 415 delivered, would be my choice

And that was the old one Jag, the Billet ones are even better.

So you would fully back this route at 450bhp for the use you suggest, without explaining to the customer any potential reliability risks because of this level on a stock engine?!

Shaun, you do make me chuckle some times, lol.
We don't even carry out a basic remap without explaining the dangers of performance tuning to the customer.
There is an inherent risk involved with ALL performance tuning, if they aren't prepared to accept the risk, well they'd best leave well alone.
In our experience the stock STi newage engine is very strong and we have carried out many conversions of well over 400hp on them so far. We have a failure rate of zero, but aren't pushing them to the heady heights that some are.

Martyn

Would have been interesting Martyn to see how a billet would have performed on my old 2 ltr block as Pat reckoned it was a good un! 400lbs on 500 pinks was not something seen too often! Am in two minds at mo on my current set up with going billet.

Martyn,
I wanted it clarifying for anyone reading it, thinking that a standard bottom end will take that kind of abuse as a matter of fact. Especially when it has been presented by a professional tuning company, that could be construed as "Yes... of course it can because it has on our engine and bashed the arse out of it".

So... let me word it another way. Would you as a Tuner say that for reliability this level of use and abuse for an OE bottom end was acceptable?

This isn't me trying to come the "cock", but you know how the slightest "statement" on these forums get's taken as black and white fact.

There is a whole world of difference betwen having a "normal" remap to 350bhp and "pushing" an OE bottom end to 450+bhp. You know that as much as I do and I would be dumb founded if you told the customer the same in both these instances. This is what I am getting at.

As a tuner Shaun, yes I would say that in my experience pushing on OE STi8 bottom end to 400+ (Which is what the op asked about) is not only fine, but very reliable if carried out by the right people, using the right equipment and fitting the correct supporting mods.
As I stated earlier, everyone gets the same talk, they either accept the risk or go elsewhere.

Martyn

Attachment 55147

Just one example, still going strong !

Martyn,
I have just re-read my initial comment to you and it does read that I was insinuating you don't explain "risks" to the customer. Sorry that was not my intention, it was more to do with clarification of how you "see it".

You have given your "opinion" now though so thanks. :)

I would not be happy running a standard bottom end with hyper-eutectic [ bullsh*t ] pistons at that power level. The ring lands crack and the pistons fall apart in our experience.

I confirm that 2.5's are MUCH worse than 2.0's.

But the risk of failure is too high for APi's liking at 450 and upwards on either.

The limiting factor in our opinion is boost on 2.5's - anything above 1.35 will crack the pistons. Ask Litcho.

Use a similar amount of boost on a 2.0 and you won't be anywhere near 450 hp.

If the customer is prepared to risk a catastrophic failure running high boost on either then so be it, BUT we';d make pretty sure that he knew we would not support a warranty claim if it did.

David APi

We've tuned a number of stock STi engines to well over 400 bhp with no failures. Yes, there is a quantifiable risk, but there always is.
I wouldn't build a 2 litre in any event, we'd go to 2.1 and have done with.

Have done with what Alan ? there is nothing a 2.1 will do that a good 2.0 will not do.

I'm sure John Banks has had over 400bhp on a standard classic UK bottom end. That being the case I don't see how the Newage STI couldn't handle 450 IF done properly and WITH the right supporting mods. I wouldn't even consider a built bottom end until exceeding 500bhp, but that's my 'opinion' hey ho.

As a customer, I think there is a difference between an arrangement where a tuner and you agree:

"Give it a go and see what happens"

and

"I am confident in this and if it doesn't work I will put it right under warranty"

If you have the dough and are prepared to take the risk, the former is worth a shot. If not, the latter everytime!

Also worth pointing out that there is no point having power unless you can enjoy it and if you're always having an ear open for an odd noise or an eye out for a spike on a gauge, you're not enjoying it!

The best builds should be "fit and forget" IMHO. That's probably what you pay for!

After 6 years in the Subaru community, I'm increasingly coming to the opinion that the car is usually not the weak link in the reliability chain........... ;) :D

I know of a number of Newage 2ltr's that have been modified properly (running 420-450bhp) and have suffered issues (ringlands).... however, these are concerning cars that have been driven "proper" on track. The same owners previously owned the same model of engine on previous cars, but running lower power figures (360bhp) and they took it and the type of use no problem.

Sounds like David (APi) has also experienced this "issue" with the ringlands on those piston types, which I am not surprised at tbh.

When you start to speak to companies who have sold well over 200 of these cars (Newage STI) to many individuals that drive them with spirit on track a lot (who don't frequent these forums), you tend to get a good picture of overall reliability.

I always say that it is as much about what you are going to use the car for, as the level of power you choose to run.

Everyone makes their own mind up on these things and have their own opinions. Based on the information I have gained, I will stick with circa 400bhp on the OE bottom end (unless I wish to accept increased reliability risks), especially as I will be spanking it on track as frequently as I possibly can. :D

Your car, your money, your risk!

Shaun, are you still sticking to the 400ish limit for reliablity on yours even though its jdm and not uk? I was (possibly wrongly) under the impression there is quite abit of difference between what is safe on a JDM to a UK STi.