Most potential using factory parts?

Correct me if I'm wrong, but I believe the OP's intent was about increases to cars that weren't/ aren't available off of the factory line, but could have been. So no engine swapping a V6 Mustang with the supercharged V8, because you can already buy that from the factory. I also don't think we should count swaps, because then it's not an increase of the existing, it's a swap.

I would say the early Mitsubishi Galant VR4. 195HP stock, but a 240HP version was available in other markets. All of the factory Mitsubishi parts are readily available. And that is just the starting point. You still have more boost, better tuning, and combos of other DSM and EVO head/ intake/ valve train/ turbo parts. The VR4 gets the nod over the DSM's only because bolt on factory intercooler upgrades exist. Their downside is the stock exhaust system, no factory upgrade and it will limit the power production.

Subaru Forrester. Rated at what, 215hp? Not many parts needed to turn it into an STI. Bonus for huge suspension and brake upgrades from the factory.

Also, 1.8T VW's. Mainly because they were so de tuned in many forms. 150HP from a turbo 1.8!?!

rslifkin wrote: It might be a more interesting challenge to ask what vehicle / engine combo has the most power potential without removing the engine from the vehicle. Use whatever parts you want, but you have to be able to install them without unbolting the engine mounts or using an engine hoist.

can you remove the transmission??

a stock 4AGE puts out 112hp... in theory... IF I can remove the trans... I can remove everything in the engine and therefore build an F/A engine... at 250+hp so a bit more than a SBC 200-400... but no where near it at KT's stated SBC 110hp beginnings....

if adding boost along with all the other bits is allowed... then there is a 700+hp 4AGTE I can point you too......

https://youtu.be/lb8taD5wchg - dyno

https://www.youtube.com/watch?v=WrQtUdvHt4Y - 8.7 sec 1/4 mile pass

Aside from Cummins diesels, I'd guess it would probably be some Corvette cam in a Camaro.

BrokenYugo wrote: Aside from Cummins diesels, I'd guess it would probably be some Corvette cam in a Camaro.

No doubt the LS line is a true contender in this debate. It wouldn't be too hard to turn a 6.0L LQ9 into an LSA with the supercharger and some factory part numbers.

The SBC, SBF, and SBM are contenders as well, but primarily because they (at some point) were all wheezers. Its pretty easy to triple the output of a 140-hp 350 from 1979 using later parts. With a bit of machine work, LT1/LT4 cams will do nicely with Vortec heads in an SBC and give you an pretty easy 400hp.

Nearly anything that was available as both turbo/supercharged and N/A versions should be a contender, provided the bottom end can handle the boost.

I also agree that the Mustang example doesn't fit the OP's qualifications. The 300hp was the V6, so getting the 1000 hp would require an engine swap, not modifications to the existing 6-pot.

Many diesels really fit this example. No throttles, just air and fuel. As long as the bottom end can hold it, you don't run out of fuel, and you don't run out of factory turbo options to prevent surge, they are rather unlimited in how much they can make. The 6.0L powerstroke is a very common performance platform. They suck at reliability with all the EGR and oil cooler issues, but once you eliminate those they are a very solid architecture. Duramaxes are in the high 800s with factory turbos these days. 7.3L 'strokes are a bit limited by their HPOP injection, but they'll take a lot.

In fact, I can't imagine many examples beating something like a Cummins 12v in this discussion.

What about Suby? There are a bunch of STI guys pushing 500hp. That's a far cry from a base EJ20 at 125hp.

Still not sure on the rules, so- Chevette with LS9 engine swap. 53 to 700 or so hp.

Death would be a sure companion, but still...

I'm thinking that the intent of the op was more along the lines of the scca update/backdating rule. Which would make me vote srt4 neon.

scottdownsouth wrote: Buick v6..add boost till you run over the crank

You blow the head gasket into the valley waaaaay before you run over the crank.

For whatever reason, it is ALWAYS the valley side. Find a 2" chunk of gasket in there, retained by the pushrods. Feels just like a blown piston except the oil isn't full of aluminum debris.

NGTD wrote:

NordicSaab wrote: The answer here is DSM. Stock is 210HP, but many have dynoed well over 600HP to 700hp on stock internals. So there is a 200% performance gain over stock using stock parts.

The 4g63 is a great engine, but there is no way that it accomplished that on a factory turbo and fueling, which is what I interpret the OP was asking for.

You guys are correct. Only using oem parts. It can be from a different car (like explorer manifold in a mustang) but must be oem. Also, no weird "Mazda head on a Volvo engine" that ish is voodoo magic.

And again- nonperformance parts. In other words, NOTHING from another company, and nothing intended for racing that's from some exclusive one off club or motoring group that's somehow related to the big manufacturer (like mugen intake on a Honda Civic)

NGTD wrote:

NordicSaab wrote: The answer here is DSM. Stock is 210HP, but many have dynoed well over 600HP to 700hp on stock internals. So there is a 200% performance gain over stock using stock parts.

The 4g63 is a great engine, but there is no way that it accomplished that on a factory turbo and fueling, which is what I interpret the OP was asking for.

Ok. If we rescope to stock turbo and fueling, a stock 1g dsm is good to about 350hp. So that is still 60% over base.

If you are a real sadist a 6g72 (3000gt vr4) can jump to well over 400 hp with a ecm reflash.

Streetwiseguy wrote: Still not sure on the rules, so- Chevette with LS9 engine swap. 53 to 700 or so hp. Death would be a sure companion, but still...

How did you miss the "no motor swaps" part?

oldeskewltoy wrote:

rslifkin wrote: It might be a more interesting challenge to ask what vehicle / engine combo has the most power potential without removing the engine from the vehicle. Use whatever parts you want, but you have to be able to install them without unbolting the engine mounts or using an engine hoist.

can you remove the transmission?? a stock 4AGE puts out 112hp... in theory... **IF** I can remove the trans... I can remove everything in the engine and therefore build an F/A engine... at 250+hp so a bit more than a SBC 200-400... but no where near it at KT's stated SBC 110hp beginnings.... if adding boost along with all the other bits is allowed... then there is a 700+hp 4AGTE I can point you too...... https://youtu.be/lb8taD5wchg - dyno https://www.youtube.com/watch?v=WrQtUdvHt4Y - 8.7 sec 1/4 mile pass

Did the 4age come with turbo? No. It did get a supercharger though.

In reply to Trackmouse:

With that expanded definition the answer in a car is likely a LS1 Camaro/TA with LS9 (ZR1 Corvette) heads, cam, and blower bolted on it(probably a 100%+ increase, 300 to 600hp+). Or maybe some real wheezer 350 (as low as 145 HP SAE net) 2nd gen Camaro with everything but the block and maybe the crank replaced with bits from the solid lifter engines and maybe Vortec heads if hacking an old style manifold to work with them is acceptable, your potential there might be as high as 400hp.

I'll offer a prize to someone who can come up with more percentage gain than a 12v Cummins.

The prize is: You get to say you won.

Sounds stupid, but a Mazda b2000/2200 would on percentage be up there ...

A stock b2000 puts out a ball tearing 84hp. Add b2600i fuel tank, f2t turbo manifold and turbo (possibly hybrid the turbo with other Mazda turbo parts), mx6 computer and loom, 929 inlet manifold, 13b turbo injectors etc

Stock Fe compression is about 8.4:1 and as you guys have seen with swanks mx6, the Fe/f2 engine takes plenty of punishment. I'd say 250+HP on only oem parts whilst tricky to find the right combo should be entirely doable. That's very nearly a 300% HP increase.

There may even be more power to be had there with an f2 and more tinkering.

In reply to daeman:

That's impressive. You may have won this.

Trackmouse wrote:

Streetwiseguy wrote: Still not sure on the rules, so- Chevette with LS9 engine swap. 53 to 700 or so hp. Death would be a sure companion, but still...

How did you miss the "no motor swaps" part?

Pfff- Rules. I don't need no stinkin rules.

In reply to daeman:

This gives me an idea. How much power is a pieced together Ford 2.3 good for? Those came a low as 88hp in NA trim, the SVO was good for 205hp stock.

Are we talking just horsepower here? Because (for instance) I could put bigger discs brakes up front and discs in the back of a 2nd Gen F-body with nothing more than late model Caprice spindles and Blazer rear brakes. Or you could upgrade a Fox-body from 4-lug disc/drums to 5-lug discs all around with nothing but SN95 parts (AFAIK).

BrokenYugo wrote: In reply to Trackmouse: With that expanded definition the answer in a car is likely a LS1 Camaro/TA with LS9 (ZR1 Corvette) heads, cam, and blower bolted on it(probably a 100%+ increase, 300 to 600hp+). Or maybe some real wheezer 350 (as low as 145 HP SAE net) 2nd gen Camaro with everything but the block and maybe the crank replaced with bits from the solid lifter engines and maybe Vortec heads if hacking an old style manifold to work with them is acceptable, your potential there might be as high as 400hp.

That's pretty much an engine swap, though. You're throwing most of the original engine away.

The nice thing about the rotaries, you don't put parts into them, you just take metal out of them. Labor costs how much to the backyarder?

Ok... I'm still arguing mitsubishi, but if we are playing the family game, a 1.6L from a mirage makes 115hp.

This engine is in architecture the same thing as a 4g63/4g64.

Within the family you can build a 2.3L using a 4g64 bottom end and 4g63 everything else. Throw a stock 14b on there and you are damn near 400hp.

So... meets the rules of this bench race and jumps power from 115hp to 400hp all within the same family using "stock" parts.

Approx 250% increase over stock.

In reply to Knurled:

Now that I think of it more, I guess you could use a Duramax diesel turbo or two on either aforementioned V8 with minimal modifications and make the same kind of power.

Yeah, and keeping the grassroots spirit in this, I'd like to be those parts that everyday joe gets at the junkyards. That uber rare side draft manifold for rotary engines that you "might" find in a junkyard is a "yeah...right..." Scenario.

So an LSjuan or whatever those are called with all these fancy Corvette parts is likely to not happen in the average joes budget for challenge money.

NordicSaab wrote: Ok... I'm still arguing mitsubishi, but if we are playing the family game, a 1.6L from a mirage makes 115hp. This engine is in architecture the same thing as a 4g63/4g64. Within the family you can build a 2.3L using a 4g64 bottom end and 4g63 everything else. Throw a stock 14b on there and you are damn near 400hp. So... meets the rules of this bench race and jumps power from 115hp to 400hp all within the same family using "stock" parts. Approx 250% increase over stock.

But the 1.6 isn't a 4g63/4. So "a whole bottom end and head" isn't really the same motor is it?

I'll say this: head swaps are allowed but only to the FACTORY block, no machine work, no "cutting this" or "bending that". Must bolt straight to the block, must be a junkyard findable part, must not be unicorn status, must not be from some "yeah right, when's the last time you saw one of those in a junkyard" type cars. Jeez some people sap all the fun out of these threads...

If you're talking about junkyardable stuff, then ANYTHING rare or valuable is right out. You're not going to find LS9/LSA anything in a junkyard any more than you're going to find a stack of LS7 heads.

Well, you might, specialty junkyard exist, but gosh, they actually ask what the parts are worth.

In reply to Trackmouse:

Man you're picky... OK. Start with a 4g64 (from any car! Eclipse, galant, mightymax) and do a 4g63 head swap... + 4g63 turbo stuff.

140hp to 400hp. I give up, you have my bottom dollar