Estimated HP gains - bolt on mods and reflash?

[Dimman]

Originally Posted by Mitch

As mentioned, those cars are running in classes where FI is penalized. Even then, for the past 11 years the winners of the 24 Hours of Le Mans have been turbocharged.

They've also been diesel, and that doesn't mean I want a diesel sports car...

[RegisBou]

Originally Posted by Mitch

Yeah, that statement ignores a lot. 250whp is just a peak number. It's completely ignoring area under the curve, where FI engines typically outperform NA engines of equal displacement.

I understand the hesitation to agree with that statement.

Now you must factor in a lot of things.

I read the article back in 2005 when turbo lag was a greater deal than it is today, and they did this comparison with a 2000 civic si (one being turbo the other being NA). They both used the same engines.

The N/A engines advantage in a FWD or RWD platform (no true advantage in 4WD which is why turbo 4wd's dominate all the time attacks) is lower torque through the apex enabling the driver to go WOT sooner than the turbo.

Now once the NA car is at WOT he is already exiting the corner sooner, and the revs are climbing up to the power-band. While the turbo in the same gear will be at 1/4 throttle trying to compress more pressure. Then it has to rev up to the turbo's optimal range.

Another factor I guess was the extra weight the turbo's added to the front wheels on the FWD cars.

The article was in some magazine and was about 4 pages long. THey went into great detail to explain how the NA car would be cheaper in the long run, and win more races because of better corner exit as well as not as much downtime.

I agree that now in 2011 turbo's are getting wayyyy more efficient.

But for our engines being high comp, most turbo people will have low PSI kits with more lag than low comp engines, since the low comp would be around 300whp rather than 225-250whp to compete with the NA engines.

Hopefully that makes sense..

[old greg]

Originally Posted by RegisBou

Hopefully that makes sense.

I'd like to see that article, because that makes no sense at all.

[Homemade WRX]

Originally Posted by Dimman

They've also been diesel, and that doesn't mean I want a diesel sports car...

Exactly because of the rulebook, they have a better (easier?) chance of winning...for the same reasoning they go NA because the rules are more strict on FI.

Originally Posted by old greg

I'd like to see that article, because that makes no sense at all.

took the words out of my mouth


With this being said, I'm really curious to see what NA power I can get out of a stock shortblock on pump gas.

[nrclptcnsmniak]

I stated this in another thread. With not much knowledge on engines and what not. If the cars target customer base was for modifiers then why would they build an engine with little room for growth? I guess we wont know until release.

[Mitch]

Originally Posted by old greg

I'd like to see that article, because that makes no sense at all.

I'm in the same boat. It sounds like they were trying to explain away either flaws in the cars setup or in the abilities of their driver. It makes sense for an amateur racer to want to stay NA to keep costs down, but beyond that none of that really jives.

[Mitch]

Originally Posted by Homemade WRX

Exactly because of the rulebook, they have a better (easier?) chance of winning...for the same reasoning they go NA because the rules are more strict on FI.

In the classes the cars you cited compete in, NA is favored by the rules so they use NA. In the highest class, FI is favored, so everyone uses FI. The 787B did so well its first year it was immediately banned by the FIA. Point being, professional racers pick FI or NA based on which is going to be more likely to win, and in the classes where FI hasn't been regulated into obscurity it dominates.

[Homemade WRX]

^^yup, I think we're saying the same thing but just in different words.

I was simply saying that diesel was chosen for the same reason (they could run further without fueling), not because it was the best performance platform, though Audi/VW have done some pretty awesome things with their diesel tech. Running a race engine with two pre, one main and two post injections and using various strategies of fueling to help broaden the diesel's powerband.

Now that rules have started cracking down on their tank size and they had to go back and rework things in the engine (several times). But VW is hanging onto the marketing of their clean diesels with the cars.

[ZDan]

Originally Posted by nrclptcnsmniak

I stated this in another thread. With not much knowledge on engines and what not. If the cars target customer base was for modifiers then why would they build an engine with little room for growth?

Why? Because they know that the 200hp that they're only barely able to achieve given 2.0 liters, na, and 7400rpm redline is close to the minimum required for this car to attract enough buyers to justify its existence.

Selling new cars is *infinitely* more important than leaving room for "modifiers", who will make up only a small percentage of buyers.

See the Honda S2000, also a car for modders, similarly very little opportunity to gain n/a hp easily.

The fact is, they're already close to the limit of what's realistically and practically achievable, not gonna be much to gain for cheap $$$.

[Levi]

S2000 can make up to 270 PS, stock already had 240/250 PS. The GT86 only has 200 PS. You'll see how Prosche, from the NA DI 3.8l H6 producing 400 PS in the 911 Carrera S, is going to get out 470 PS from this engine when it will go into the new 911 GT3. There is yet alot of room in the FA if you have $$$. Why spend so much for only 50 PS more when for this price you can buy cars with double the power? Because those more powerfull cars, however light you make them by stipping them down, they'll never reach the GT86's weight. Why not get a Caterman? Because it is so much more fun to modd!

[ZDan]

Originally Posted by Levi

S2000 can make up to 270 PS, stock already had 240/250 PS. The GT86 only has 200 PS.

That's because the 2.0 S2000 revved to 9000rpm, peak power at 8300. GT86 only revs to 7400rpm, peak at 7000.

Power potential is *directly* related to how high you can rev.

Scale s2000 power down by the reduced rev capacity of the 86, and you get 200hp stock vs. the S2000's 240hp.

I.e., there's *still* not a ton of potential for the stock engine for making much more power for reasonable/practical effort and $$$. You'd have to match the mods required to get 270hp out of the S2000 in order to get 225hp out of the 86.

[RegisBou]

Originally Posted by Mitch

I'm in the same boat. It sounds like they were trying to explain away either flaws in the cars setup or in the abilities of their driver. It makes sense for an amateur racer to want to stay NA to keep costs down, but beyond that none of that really jives.

I think you are right about the amateur racer thing. I was trying to help out people who want more power and want to go to the track all the time.

Showing them that NA in the long run is safer and cheaper.

The article? I read it in some magazine in France and I dont even remember the title of the mag. (Yes I am bilingual)

What i dont understand is how you guys dont get the whole turbo lag dilemma?

If you are at the limit of your tires (or close to it) in a turn and you have a lower torque NA platform with the same HP as a turbo variant, you will be able to go WOT (Wide Open Throttle) sooner than the turbo because of excess torque making the driver have to wait longer before he can go WOT in a turbo vehicle. So essentially the NA car will clim the rev range faster than the turbo car and hit peak HP faster in turn making the car itself faster if both cars have the same HP output.

Another aspect of the turbo lag is if the driver enters to fast and has to let off to rotate the car by the time the car is back on rails, the gas needs to be pushed and boost needs to build while the NA car has all available HP and torque in the rev range once the throttle is pushed down.

Another aspect is gear selection. Do you have enough revs to exit the corner? Is there enough power in the higher gear to go through an uphill turn at low rpm? Turbo lag back then was pretty bad, as it will be with low quality turbo kits most people will unfortunately buy. So if most tracks have 60mph turns...2nd gear is pointless, so 3rd gear would be the prime choice. Most turbo's in high revving cars tend to go full boost mid rpm (3500-5000) depending on the build/turbo/tune. No I am not going to explain all of this because I am assuming that you guys can put 2 and 2 together.

This is comparing cars with the same WHP levels...

If that doesn't make sense, then I have no clue what else to say..this is what the article was trying to conjure.

In good regards,

Regis

[fatoni]

Originally Posted by RegisBou

I think you are right about the amateur racer thing. I was trying to help out people who want more power and want to go to the track all the time.

Showing them that NA in the long run is safer and cheaper.

The article? I read it in some magazine in France and I dont even remember the title of the mag. (Yes I am bilingual)

What i dont understand is how you guys dont get the whole turbo lag dilemma?

If you are at the limit of your tires (or close to it) in a turn and you have a lower torque NA platform with the same HP as a turbo variant, you will be able to go WOT (Wide Open Throttle) sooner than the turbo because of excess torque making the driver have to wait longer before he can go WOT in a turbo vehicle.

Another aspect of the turbo lag is if the driver enters to fast and has to let off to rotate the car by the time the car is back on rails, the gas needs to be mashed and boost needs to build while the NA car has all available HP and torque in the rev range once the throttle is pushed down.

This is comparing cars with the same WHP levels...

If that doesn't make sense, then nothing will.

In good regards,

Regis

the issue is that you are using wot as a quantitative term when it is qualitative. it doesnt matter if you can get more on the throttle earlier simply because you have more tq available in the turbo in your situation. you are basically telling us that tq is bad. and with decent turbos like the ones readily available today turbo lag is all but a non issue not really even measurable by most drivers. there may be a decrease in throttle response but im pretty sure that all that extra tq you are saying is bad more than makes up for it

[old greg]

Originally Posted by RegisBou

Showing them that NA in the long run is safer and cheaper.

That really depends on your goals and what you're working with. If you just want an extra 20hp from a 2L four, n/a will be cheaper and more reliable. If you want an extra 150 hp from that same engine, n/a will be jaw droppingly expensive and require daily rebuilds.

Originally Posted by RegisBou

What i dont understand is how you guys dont get the whole turbo lag dilemma?

If you are at the limit of your tires (or close to it) in a turn and you have a lower torque NA platform with the same HP as a turbo variant, you will be able to go WOT (Wide Open Throttle) sooner than the turbo because of excess torque making the driver have to wait longer before he can go WOT in a turbo vehicle. So essentially the NA car will clim the rev range faster than the turbo car and hit peak HP faster in turn making the car itself faster if both cars have the same HP output.

...
If that doesn't make sense, then I have no clue what else to say..this is what the article was trying to conjure.

Ok, so here's why that makes no sense.

Throttle position %age is irrelevant, if you have enough excess traction to support, say, 40 ft*lbs of torque your tires don't know or care whether that's you at WOT or just 5% TPS. 40 ft*lbs is 40 ft*lbs. So in your example you have two otherwise identical cars in identical situations, both applying identical amounts of torque to the tires. Neither has an advantage.

At the corner exit, though, when traction is less limited, between two engines of equal displacement and equal peak power the turbo engine will have much more midrange torque. That means that (since both cars have identical gearing and corner exit speed) the turbo car will have much better drive out of those not quite 3rd gear corners you mention.

Originally Posted by RegisBou

Another aspect of the turbo lag is if the driver enters to fast and has to let off to rotate the car by the time the car is back on rails, the gas needs to be pushed and boost needs to build while the NA car has all available HP and torque in the rev range once the throttle is pushed down.

Um... Have you ever driven a turbocharged car? Even my car, which with its idiotic pre-turbo cat is actually fairly laggy, lag at ~4500 rpm is less than half a second.

Originally Posted by RegisBou

Most turbo's in high revving cars tend to go full boost mid rpm (3500-5000) depending on the build/turbo/tune....
This is comparing cars with the same WHP levels.

And here's where you jump the tracks completely.
Lets say this N/A 2L has a few mods and is making ~220 horsepower. A turbo sized to make 220 hp on a 2L engine would be a absolute spool-monster with peak boost at 2500 rpm at most. The kind of turbo that needs 5000 rpm to hit peak boost on a 2L is capable of making ~600+ hp. No one in their right mind would use such a huge turbo to make 220 hp.

And it amuses me how you keep referring to 2005 as if it were some sort of automotive dark age where turbos were made from rocks or something. I mean, hell, the GT30 has been around since 2002/2003. It's not as if we're talking about the 1970's here.