The street Subaru WRX STI puts out 305 hp (turbo). I've read of modified versions putting out 550 hp but not sure for how long it would do that --- a race or maybe 2? Same engine core can do 1200 hp on a dyno. That's a lot of horses for 2L 4 cyl.
Well, here in the Northeast, WRX engines are reliably putting out 500 - 800 hp for YEARS, both on the street and on the track. My son's Mitsubishi 2.4 (about the same bottom end strength as a Subaru 2.5) put out 680 hp at the wheels on a dyno (you do the flywheel math - it's over 1,000 hp) for over 120 passes at Epping Dragway in New Hampshire and then he sold it - It may be still running, out there. Oh, BTW, that car was also his daily driver - yes, over 500hp on the street. Yes, it's a lot of horses, but that's the way of computer-controlled engine management, these days.
My son ran at the drags. His friend, ran on a road course with another Mitsu Eclipse. THAT Car was running 1,050 HP at the crank. His car was "middle of the pack" level. Just imagine what he was running against in a class of Eclipses, Lancers and WRXs out there. The 50's, 60's and 70's way of thinking about horsepower and performance is way different, today.
All that said, IMHO, anything over 250hp in a light, 550 Spyder would be just plain dangerous for the inexperienced driver. If you're not an Andy Lally or Spencer Pumpelly, you won't understand what you're driving and/or respect it.
"If you're not an Andy Lally or Spencer Pumpelly, you won't understand what you're driving and/or respect it."
Well that counts me out... I don't even know who those guys are 
just kidding.
Honestly that is why I prefer N/A engines it is just more predictable. IMHO
We have several local STi's that simply have bigger injectors and a bigger turbo coupled to an E85 tune that are putting down 500-600hp as daily drivers (stock bottom end). Properly maintained, they seem to be holding up very well.
As for big NA power, it is much less chartered territory since the Subaru "tuner" world is very turbo-focused. I've seen Jake Raby pull an extra 20-30hp out of a stock 2.5L with head work and cam grind (plus a few "tricks"). I know he's also done a couple of big bore custom builds 2.6L and maybe even a 2.8L that would get you to the NA power you desire, BUT now you're talking big bucks also...
One of the reasons I mentioned "dyno proven" 175hp is that we see engine builders and others touting all kinds of HP numbers for NA motors. When we first started playing with Suby motors a client sent us a "210hp" NA build from a well known Subaru sandrail source... big surprise when it dyno'd at 147 to the wheels, the EXACT figures that our 175hp stock mill does! I've since seen NA motors advertised at 10% more power than that, with nothing more than cams and a custom ECU/tune, but I've never seen a dyno sheet to back it up. Not saying that they aren't making that kind of power, but I am skeptical.
Gordon....yup a Quaif absolutely ! I had a ZF on the shelf in my garage and after 9 years I got to use it in my current car. Totally understand the need for a lot of extra beef in the trans. dept. I don't think there's any sound worse than when a transmission grenades on you and you can hear the hard parts scattering on the pavement as you come to a crunching stop !.....Bruce
I think Stan recently mentioned the "West Coast Dyno Factor" in a post.
My neighbor is into racing motorcycles and he says the same thing about West Coast bike engines - what they tell you it "dynos at" out there might not live up to what it appears to be when you get it.
I think some of the horses bolt from the shipping crate in transit and head for the hills...
Carey.....Thanks for your input. I really appreciate your input and I'm sure to have more questions in the near future. Summer is not far away (at least here in SoCal) and I'd like to get in a couple more cruises before I say good bye to "Rhonda" and start on my next adventure with a 550........Bruce
Bruce how do you deal with the sun on your head in a 550 spyder?
Yeah, there are certainly people who's dyno charts are a little optomistic, but a naturally aspirated engine dynoed at or near sea level will never make the same power at higher elevations even when rejetted for the area (the air's thinner and you just can't pack as much into the cylinder). Not sure how much this affects turboed engines. I'm not saying all west coast engine builders are honest; this is just a factor that has to be taken into account.
Gordon........Well said. Many years ago now I was sent to the Clayton dyno factory in El Monte Ca. to attend a class on how to operate them. The people I worked for at that time were buying 4 of them. One of them was for dual rear axle trucks, two were for cars and one for engines. One of the first things they told us is that dyno's can lie and the operator is in control of how big the lie will be. They called it "Flashing". They also said that it was easier to do it on an engine dyno. Chassis dyno's had too much "lag" to get any dramatic numbers. I didn't get to operate the engine dyno so other than what was said in that class is all I know about it. The point of my comment is only that the operator CAN influence the HP output. Out here in SoCal, those that have dyno's and work on similar size engines know who they are that use "Flashing". In my opinion, having talked to some of them, they are reluctant to say who they are for obvious reasons. In the end, I have cautious belief in the numbers I see on a dyno graph....Bruce
Ray....I have never had the top up on my Speedster. So far. With the drought seemingly coming to an end maybe that will change. Hat, sunglasses, and my sun visors have done the trick up to this point. It's the first convertible I've driven for any length of time and I'm lovin it......except when i turn my head left and see a 10 wheel truck tire next to me singing away ! Ha ha !......Bruce
LoL, yeah I know you feel like they are going to drive over you On the other hand you will need a WWI flight head gear and glasses for any long driving othewise you will suffer out in the wind for all that time. Ah well just get a helmet and glasses.
Gordon Nichols posted:I think Stan recently mentioned the "West Coast Dyno Factor" in a post.
That's the (in)famous: "Orange County Correction Factor", or apx 1.1- 1.2x.
Jack Sachette's (JayCee) reads about that high, in my experience. That's why lots of SoCal shops use his dyno. If the competition is advertising numbers that are 10- 20% high, not using the same piece of test equipment puts those builders at a competitive disadvantage.
It's a slippery slope, and unfortunately not uncommon practice in our little hobby. Keep that in mind the next time somebody tells you all about their 110 hp 1776 with stock heads and a 110 cam.
Right. Who was the Lord of "Smoke and Mirrors"?
There is a semi-involved procedure for calibrating an engine dyno (any dyno, really) involving a set of standard weights and a bunch of weather factors (temp, Baro pressure, Humidity, Altitude, etc.) The weather stuff is done by a small weather station computer connected to the dyno computer (if it's a modern, decent dyno) so THAT stuff should be automatic, but how many techs do a wet bulb test for comparison just before they start a series of pulls? And how many check with the standard weights before those pulls, too? Maybe they checked a few times when the thing was new and found that not much changed over time, but how long has it been since their last, thorough calibration test? And do they make the calibration sheet (paper or electronic) available for clients?
After my engine seized when it was first built, I had to have the case welded and then had an align bore done on the cam journals at a local Motorcycle machine shop. They had a full bike, wheel dyno out back that got calibrated every day it was used and the calibration slip, along with the pull results, went with the tested bike. THAT is what you want to see.
WOLFGANG posted:My VW transaxle codes list has several codes for a transaxle with Limited Slip Differential (LSD). How rare are they?...
I think you'll find that ZF lsd's are pretty rare in North America, Greg. If you go on the Samba and search for type 1 (swing and irs) ZF's for sale you'll probably find that the guy to speak to is Bruce (his screen name); he finds them south of the US border. Bruce is a friend of mine, has taken apart as many transaxles as anybody in the hobby (I know he rebuilds more than 1 a month) and I don't think he's ever found 1 in a local trans. There are some inaccuracies in those charts; the semi- automatics aren't teeming with lsd's. They might have technically been an option, but again, never seen or heard of one in a semi-auto trans. Guys do take them apart looking for 2.25 2nd gears, and they're just not out there. Al
ZF LSDs are rare like hen's teeth. Rare like $1500 for a used one rare.
Air cooled Bruce has a ZF in his car. I covet it. I don't know how much it is needed except in hard cornering like drifting. My car seems to spin both rear tires evenly in first gear as I can see two streaks. Not like a live axle car which will lift the drivers rear tire due to axle torque. If you have a peg leg rear end (non limited slip) it will spin the passenger side tire like crazy.
Stan Galat, '05 IM, 2276, Nowhere, USA posted:Gordon Nichols posted:I think Stan recently mentioned the "West Coast Dyno Factor" in a post.
That's the (in)famous: "Orange County Correction Factor", or apx 1.1- 1.2x.
Jack Sachette's (JayCee) reads about that high, in my experience. That's why lots of SoCal shops use his dyno. If the competition is advertising numbers that are 10- 20% high, not using the same piece of test equipment puts those builders at a competitive disadvantage.
It's a slippery slope, and unfortunately not uncommon practice in our little hobby. Keep that in mind the next time somebody tells you all about their 110 hp 1776 with stock heads and a 110 cam.
George could do it...
Seems like the 2.5 NA should be capable of about 250 horses at the crank, given the right cam. But, right, nobody bothers because turbos exist.
Well, almost nobody.
If it were me I'd do the standard Frankenmotor with the standard Delta 2000s, standard +1 injectors, and see if I could port-match the intake runners to the heads. I don't even know if it'd be worth grinding on the heads at all. Maybe someone does.
I don't know, either, how the engine management system should be hacked to get the most out of this...
Then the headers. Making good long-tube, equal-length headers would probably be a project in itself.
Traction! The zf's are rare. Especially a swing axle unit. There are better units available. I sold a couple GT units. He made a swing axle T/B unit similar but superior to quaife by some. Then there is the LSD (limited slip diff, same as ZF, but much better) Paul designed with a higher quality clutch disc/plate material.. these units are not inexpensive, 2,150,-2,400.
Doesn't Paul also make clutch packs for the ZF?
Yeah, Stan, he originally designed replacement composite friction and hardened plates for Porsche's early 904 LSD (made by ZF), and found they fit in the type 1 irs ZF as well.
I remember him saying he was going to. Cs
Next time the box is apart, the ZF is getting rebuilt with those plates and clutches.
Panhandle Bob posted:Stan Galat, '05 IM, 2276, Nowhere, USA posted:Next time the box is apart, the ZF is getting rebuilt with those plates and clutches.
Stan:
So, is that your project for the first half of this Saturday?
I will start this out by staying that this is going to sound stupid. My first spyder with the 120 hp aircooled engine did not have a LSD. My 165 hp suby spyder had a LSD. My suby spyder with the LSD was faster. My aircooled spyder without the LSD was more fun. The LSD car could go through corners faster with very little drama. Going through corners in the non LSD car the rear end would slide out more with the outer tire finally grabbing the pavement and the inner tire spinning like hell. Lots of drama. It always put a smile on my face. I know. Stupid. If I build another spyder, using a LSD will be a tough decision. Do I want speed or grins? 