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Determining my Stage 2 WRX speed by comparing to other cars

1292 Views 66 Replies 9 Participants Last post by  silver_scooby
I recently took my '21 wrx to stage 2: GS Intake, ETS Jpipe, AWE Touring Catback, and a pro-tune. Mustang dynos says I'm 301 whp and 280 tq, and I was told it's about 371 at the crank (about 100hp up from stock).

I am trying to know what kind of 0-60 or 1/4 mile my car would get assuming it was launched well.

I was comparing it to an audi S5 to start. The audi is 354 crank HP, AWD and weights about 600lbs more at 3900lbs. Car and driver says the S5 does about a 4.3s 0-60 and a 12.9s 1/4 mile.

Would it be reasonable to assume, that if launched well, my car would do it a bit faster since it is more hp and lower weight?

I'm unsure how many other factors are involved like gearing and transmission, etc. Any thoughts would be great. It's not super important, I just like to think about these things and am curious how I'd match up.
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I think boutique builders have come a long way in the last 2 decades, particularly on Subaru flat 4s. There are three things here that I think people always confuse - Reliability, Longevity, and Power Handling. Built blocks tend to have equivalent reliability, superior power handling but at reduced longevity. Example: an F1 engine needs to be rebuilt every couple thousand KMs so it's longevity is quite poor compared to a street engine, but it MUST be reliable during operation to be competitive.



And this is almost always due to the fact that a modern automotive factory possesses superior tooling that is out of reach of boutique builders. There are exceptions, like when the aftermarket acquires an entire factory line from the manufacturer. A rebuilt SBC from 1969 might have lasted as long as the factory block from the same era because of the crude factory tooling, but also remember that 100k miles back then was considered very high mileage. You and I know this because we've both work(ed) in the automotive tooling business. Most people do not.

I also think there's an issue with people "oversizing" a built engine for their needs. They think "well if I'm replacing the engine I might as well go with the block that can handle 1000 hp" not recognizing material choices may impact longevity. You should always choose the right combination of parts for the application. Not having clear and concise goals is the main issue here.
Now those are the two ends of the spectrum, large OEMs vs small shops. What happens in the middle?

HKS, Alpina & Brabus make & help develop some OEM parts but also sell built engines. How would their longevity compare?
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You typically dont have middle road.

My company has absolutely insane amounts of money to spend on specialized equipment and inspection processes. Machines that cost millions of dollars to crank out whatever they want.

Before we sold our US engine component shop to Eagle they could spit out cams, cranks and blocks without missing a single feature by .01mm by the thousands.

In the back of my particular building we have components on test benches absolutely getting the hell beat out of them for months on end to ensure what we are making will hang in there. I've seen coil springs, stab bars and disc springs cycled and stretched so far beyond anything they would ever see over and over and over again for 6+ months.

The automotive world is funny and the real benefit of a smaller shop is a unified product. Where in the OEM space you can have components from a myriad of suppliers all go to a single thing. For instance when Chrysler was saying they make the pentastar in house the company up the road from us was cranking out pentastar blocks in massive volume, cams and cranks as well.

A smaller shop will do blueprinting. That is taking exact measurements of every single component. It doesn't mean it's better, it just means there is a known quantity. You'll have exact clearances so you don't have to worry about one engine being a little looser or tighter.

It's all really academic as Chrysler rigged the viper into existence out of spare parts and those stupid things will go well past 100k hitting the track and strip every weekend, but vw engineers the crap out of everything and a Jetta is scrap in 50k.
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Hmm, interesting. A few million is pretty normal for most industrial machines. I guess you are right about the lack of a middle ground. Looked up the suppliers out of curiosity and HKS is 60+ mn$ revenue. I'd rather have better tolerances than blueprinting, the latter doesn't do you much good for longevity.

The viper is glorious, no need to shit on one of the best cars ever made :p. Would love to have one as a weekend car. Wouldn't drive it in the rain though, that was an experience I won't forget. On a more serious note, I'm more likely to trust rushed projects because managers have less time to fuck with the design. Every time I help friends fix VWs, the parts and design decisions remind me of projects lead by bean counters.

Over-engineering is a vague term and in most organizations it's a bad thing. It usually means that you have "technical directors" who are really penny pinchers with outdated technical experience questioning every design decision and cheapening every component. Worked on two projects simultaneously for the exact same type of machine. One was a 3 month project designed to be a stopgap and another was a 2 year project to make the long term product. The first one went fine and the stopgap is still in production with healthy profits and minimal quality issues.

The 2nd one started with a shocking number of brilliant ideas and great designs. After about 2-3 months of cost review meetings in which nearly every good idea was tossed because it cost 5-10% more, everyone had more or less checked out and was throwing in the cheapest and easiest designs they could think of just to avoid talking in those meetings. The end result was a nice looking machine that cost maybe 15% less than the stopgap but was scrapped because of quality problems that made some customers angry enough to try & sue us.
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Now those are the two ends of the spectrum, large OEMs vs small shops. What happens in the middle?

HKS, Alpina & Brabus make & help develop some OEM parts but also sell built engines. How would their longevity compare?
AFAIK, Alpina and Brabus do not build the rotating assemblies in the cars that they modify and sell to the public.

HKS would suffer the same problems as IAG.

None of the specialty shops would have the financial justification to onboard the types of tooling that Subaru has installed on their manufacturing lines. IAG is one of the premier EJ builders on the planet, wholly specializing in a single platform and though they have probably invested in some custom tooling to make rebuilds easier, they aren't the types that you'd see on a Stellantis manufacturing line. HKS has built a number of engines over the years (RBs, 4Gs etc.) and are even less specialized. I'd bet they do things the old fashioned (hot-rodder) way.
Alpina specs their own cranks, pistons, valves, etc. in fairly standard bmw blocks and sometimes bores them out. Whether they make them in-house I don't know but they do machine some bmw blocks and heads in-house.

HKS gets the bulk of their revenue from OEM parts development and mfg. Their builds and aftermarket parts are more side projects.
Hmm, interesting. A few million is pretty normal for most industrial machines. I guess you are right about the lack of a middle ground. Looked up the suppliers out of curiosity and HKS is 60+ mn$ revenue. I'd rather have better tolerances than blueprinting, the latter doesn't do you much good for longevity.

The viper is glorious, no need to shit on one of the best cars ever made. Would love to have one as a weekend car. Wouldn't drive it in the rain though, that was an experience I won't forget. On a more serious note, I'm more likely to trust rushed projects because managers have less time to fuck with the design. Every time I help friends fix VWs, the parts and design decisions remind me of projects lead by bean counters.

Over-engineering is a vague term and in most organizations it's a bad thing. It usually means that you have "technical directors" who are really penny pinchers with outdated technical experience questioning every design decision and cheapening every component. Worked on two projects simultaneously for the exact same type of machine. One was a 3 month project designed to be a stopgap and another was a 2 year project to make the long term product. The first one went fine and the stopgap is still in production with healthy profits and minimal quality issues.

The 2nd one started with a shocking number of brilliant ideas and great designs. After about 2-3 months of cost review meetings in which nearly every good idea was tossed because it cost 5-10% more, everyone had more or less checked out and was throwing in the cheapest and easiest designs they could think of just to avoid talking in those meetings. The end result was a nice looking machine that cost maybe 15% less than the stopgap but was scrapped because of quality problems that made some customers angry enough to try & sue us.
I'm not crapping on the viper at all. It's a brilliant vehicle and it's humble origins as a garage built hodgepodge experiment on a budget to one of the most legendary sport cars to ever hit the streets is quite impressive.

When I see over engineering is taking simple concepts then making them and complex as possible for no reason more than you can.

We have an entirely different problem in the transmission world. They spend absolutely absurd money when a simple solution would be easier to manufacture, more reliable, and cheaper.
I'm not crapping on the viper at all. It's a brilliant vehicle and it's humble origins as a garage built hodgepodge experiment on a budget to one of the most legendary sport cars to ever hit the streets is quite impressive.
Yeah that was a joke comment, mimicking the response of Lancia fans :p.

When I see over engineering is taking simple concepts then making them and complex as possible for no reason more than you can.

We have an entirely different problem in the transmission world. They spend absolutely absurd money when a simple solution would be easier to manufacture, more reliable, and cheaper.
That is a different problem. Better problem tbh, although I wish they would focus that overengineering on programming for a bit. Too many autos bog the engine at low revs until gas pedal is halfway down and then direcltly send it to redline.
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