Track

there is lots of assuming here. Lets try to stick to a general NA power mods or sets that match together. Rather than making crap up about 200whp turbo vs. 170 whp NA.

There is no real way to know that, I can certainly say a 200whp with a 8k redline would spank on a stock redline 170whp NA. but who the ---- would make a 170whp NA with stock redline? great, so who is really going to get a 200whp miata that spools up at 4.5k rpm? no one really, and they certainly don't make stock torque at 2k rpm and lets get another thing straight, most miatas making 170whp are only making 150 ft-lb of peak torque, while a 200whp miata could be making gobs and gobs of torque at some area of the rpm range.

so, now that we see that this rant is pointless, lets talk about NA power mods rather than make ---- up. Like I just did.

Personally, I am a fan of IHE and ECU idea. the ECU can really work out the shitty stock tune and with some mild valvetrain work, you can really pick up the power. problem? our heads don't flow very well :/

bigx5murf

Ok, I think I get what your saying now. You're saying that NA cars will have torque sooner than a turbo car in the powerband. I can see that, problem is the turbo car is capable of way more torque.

Johnny2Bad

The turbo car is capable of "way more" (if you say so, seeing we're referring to 170 and 200 RWHP cars) horsepower. The question is where the torque that the horsepower is derived from (dynos only measure torque ... then calculate horsepower from that value) appears in the power band, and how broad is the torque curve overall.

200 ft-lbs at 3000 RPM is 114 HP.
200 ft-lbs at 5252 RPM is 200 HP.
200 ft-lbs at 7000 RPM is 266 HP.

If the N/A car's peak HP is at a lower RPM than the turbo car (and I would expect it to be so) the N/A car could be making more torque as well, despite a lower peak HP figure.

Maybe the N/A car produces peak HP at 6000 RPM and the turbo car produces it's peak at 7000 RPM. These are not huge differences, but torque at 170 HP peak @ 6000 N/A would be 149 ft-lb; at 200 HP peak at 7000 F/I-Turbo it is nearly identical at 150 ft-lb.

With small rear-end ratio differences they are accelerating at the same rate and speed. With identical rear-end ratios the N/A car is accelerating at the same rate at 6000 as the F/I car at 7000.

The question isn't the power numbers themselves but where is that power and what is the RPM range where each car is producing, say 80% or more of it's peak torque value? The car with "more torque under the curve" will win the drag race.

It could just as easily be the turbo car ... the point being you can't tell simply by the two differing HP ratings of the two examples. A 170 HP car could beat a 200 HP car, or vice versa. The torque below the curve tells the rest of the story and gives you your winner.

And I'm not going to add anything more to this ... it's off topic (except insofar as building N/A might not be completely insane, assuming you're OK with the power level and don't want to go higher) and I'm done. Interested people can google for plenty of good info on the concept.

Track

This is the stupid part. You assume linear torque and that is not the case, so please lets stop with the hypothetical power bands. While I am not saying that you guys are wrong, its just silly and we are comparing 2 totally different budgets here.

sixshooter

Generalities are very generalized.

And often disproven by the exception.

shuiend

Below is my Garrett 2554 on a Begi setup. You can have lowend torque with a turbo.

Johnny2Bad

I said "maybe". It's an English word ... look it up.

I "assumed" nothing:

Track

maybe they make 10000 hp at 8000 rpms.

Johnny2Bad

Nice curve, shuiend. Of course you can make torque with a turbo.

Here are two curves, one n/A Miata and one turbo Miata. Both are from drag racing cars.

The N/A has peak HP of 156.5 and peak torque of 151.03
The turbo car has peak HP of 177.00 and peak torque of 154.00

Look at the area under the torque curves for both engines. The N/A has the superior torque curve. Whether that translates into a win or not ... well, that's why you run the race.

I chose these two because I pretty much had to ... there was only 1 N/A miata with a chart, and only 1 turbo Miata with similar torque. It's just illustrative of the concept of how the powerband of tourque output varies between the two induction options. These are real, built and tested motors used in drag racing.

shuiend

Can you give more details on that turbo setup?

It looks like the that N/A car has more torque for about 1000rpms. I don't drag, but I would assume that the only time you are between 3k-4k would be in your first gear in a drag race.

I still believe that you can build a turbo car that will have better low end torque then any N/A or supercharged motor as long as you are not shooting for more then 200hp.