What coilovers should I purchase?

[StraightOuttaCanadaEh]

Originally Posted by Gforce

Well, you need stronger connecting rods before you need bigger injectors. You do not need an oil cooler. The stock clutch is perfectly ok for the standard size Supercharger pulley. The stock clutch is crap in pedal operation but grips fine.

My theory was to put the eForce onto the unmodified engine and wait until it breaks. Edelbrock and Cosworth both claim their basic Superchargers won't break this very robust little engine. If it breaks then, assuming it is salvageable, is the time to build it. Other sources indicate forged rods are enough for 400 HP.

Subaru builds a turbo version of this engine so we know it is strong enough to be boosted.

The diff is good for a lot of torque as it comes out of a Lexus. The transmission is reported to be based on an Asian light truck transmission and should be good. Axle shafts may not be strong enough though. Not sure if Subaru just fits the STI driveshafts but if they do then they are beefy enough.

To be honest, the 30% power and torque increase you get from any of the three or for screw or rotor type Superchargers available for this car is plenty for a daily driver. Harrop of Australia and Edelbrock use the 1320 Eaton. Cosworth used the more closely matched 960 (the number is the capacity of the air pump chamber per revolution). Sprintex also from Australia used a screw type.

Litchfield UK elected to use a Rotrex.

While I admit that I have no knowledge of different types of superchargers and how they differ in operation and what effects those might have on the engines they're boosting, I do agree with you that most tuners oversell the supporting mods. For daily driving, you probably just need what's in the package.

[Gforce]

Originally Posted by StraightOuttaCanadaEh

While I admit that I have no knowledge of different types of superchargers and how they differ in operation and what effects those might have on the engines they're boosting, I do agree with you that most tuners oversell the supporting mods. For daily driving, you probably just need what's in the package.

The thing about the Edelbrock and Harrop decision to use the 1320 out of the box is there is lots of capacity to increase boost later. Cosworth decided to use the smaller Supercharger which better matches the 2.0 capacity. Cosworth says they could get more than 300 HP out of this size but anything over 290 is unsafe for the stock bottom end, by which they mean the rods which we know will bend at very high bmep.

[D_Thissen]

@Gforce The FA20 in our cars and the FA20DIT that's in the new WRX are different motors. The DIT has a ~10.5:1 CR vs our ~13:1, different fuel systems (DI vs DI/PI) and I believe different rods.

"My tuner verified for themselves that Shell 91 gives the best engine performance in my area. The 92 and 94 offered by others has too much ethanol in it and does not give better real world performance than ethanol free Shell 91. My seat of the pants dyno confirms that with my other three cars, two of which are also boosted."

The butt dyno is irrelevant source of measurement.

[strat61caster]

Originally Posted by StraightOuttaCanadaEh

While I admit that I have no knowledge of different types of superchargers and how they differ in operation and what effects those might have on the engines they're boosting, I do agree with you that most tuners oversell the supporting mods. For daily driving, you probably just need what's in the package.

The only thing you'd need is an oil cooler if it was tracked and a catch can if you felt like it. They were totally overselling you unless you wanted more power than what's 'in the box' so to speak.

And that's probably what they usually do, people go to the shop to get more than just the off the shelf package.

Super off topic, but I don't think OP has been back so whatever.

[Gforce]

Originally Posted by D_Thissen

@Gforce The FA20 in our cars and the FA20DIT that's in the new WRX are different motors. The DIT has a ~10.5:1 CR vs our ~13:1, different fuel systems (DI vs DI/PI) and I believe different rods.

"My tuner verified for themselves that Shell 91 gives the best engine performance in my area. The 92 and 94 offered by others has too much ethanol in it and does not give better real world performance than ethanol free Shell 91. My seat of the pants dyno confirms that with my other three cars, two of which are also boosted."

The butt dyno is irrelevant source of measurement.

The FA20 is built in two versions: turbo and non turbo. Which is what I wrote. I don't think we know for sure what Subaru may have changed when upgrading the engine for forced induction. The crank is an unlikely candidate for change given that it is the single most expensive engine part. We know the pistons are different, and I mentioned that reducing the compression ratio would form part of any built engine for more boost. It is doubtful the rods are different for the wrx version but the STI version would need stronger rods.

As for the relevance of the butt dyno well that's the only one that counts for a daily driver. Also, accuracy of butt dynos may vary. I have an excellent one, according to my wife the only judge of same I pay any attention to.

[D_Thissen]

Originally Posted by Gforce

The FA20 is built in two versions: turbo and non turbo. Which is what I wrote. I don't think we know for sure what Subaru may have changed when upgrading the engine for forced induction. The crank is an unlikely candidate for change given that it is the single most expensive engine part. We know the pistons are different, and I mentioned that reducing the compression ratio would form part of any built engine for more boost. It is doubtful the rods are different for the wrx version but the STI version would need stronger rods.

As for the relevance of the butt dyno well that's the only one that counts for a daily driver. Also, accuracy of butt dynos may vary. I have an excellent one, according to my wife the only judge of same I pay any attention to.

I never wrote that the crank was changed.. The USDM STI is also an older EJ motor.

[strat61caster]

Originally Posted by D_Thissen

The STI is also an older EJ motor.

In Japan the STI is using an FA20.

[D_Thissen]

Originally Posted by strat61caster

In Japan the STI is using an FA20.

Fair enough. I was under the assumption (seeing as how we are in NA) that we were talking about N. American cars.

[Blood]

Originally Posted by strat61caster

In Japan the STI is using an FA20.

No... The STI in Japan is still using an EJ207 as it has been for the past 20 years.

[nikitopo]

WRX S4 and WRX S4 tS use a FA20DIT engine, but technically speaking they are not a real WRX STI.

[Racecomp Engineering]

Originally Posted by strat61caster

Yes you tease.

Originally Posted by redlined600

Yes, make this thread great again. Let me rephrase, make this thread great.

Here is a shock dyno for a very fast racecar. Spring rates are very stiff. No other comments.

Rebound on bottom (yes bottom).

- Andrew

[gramicci101]

Originally Posted by Racecomp Engineering

Here is a shock dyno for a very fast racecar. Spring rates are very stiff. No other comments.

Rebound on bottom (yes bottom).

- Andrew

So what you're saying is that if I put very stiff springs and shocks on, I'll have a very fast racecar.

Got it.





/s

[nikitopo]

Do you have a photo of the car?

[Racecomp Engineering]

Originally Posted by nikitopo

Do you have a photo of the car?

Not a BRZ. It's a mid-engine FIA GT3 car.

Less low speed rebound than a BRZ!


- Andrew