Twin Turbo 3 liter vs V8 Powerplants

[Afshin]

I have always been a turbo guy and love high revving engines such as in the M3 and S2000. However, I certainly would not call anyone with a clear preference for high displacement engines as lazy. The whole point for grown men and women putting so much attention, time and dare I say affection for a silly machine is enjoyment.

The instant kick and response from a V8 is always a blast and can generate a smile I would never tire from it. Yet, for me, building the power in a turbo car or a nice high revving engine (not a civic) helps me better connect with the machine and as such greatly enhances my driving experience. For others, powerful immediate thrust is the key. On the same token I love open track events and attempting to learn to balance my car's handling thru 20 minutes of high speed turns. In short, I somewhat prefer the element of pushing and controlling the car thru turns than pure push me in the back of the seat thrust, though I certainly want and appreciate both. Others get more kicks out of faster quarter mile runs (again more thrust). Some people prefer foreplay as for them it increase the ensuing pleasure, for others it is a distracting to the main event and a nuisance

Calling a group lazy based on what gives them the bigger kick, to me shows a myopic perspective. Heck, if immediate kick and power puts the bigger smile on your face, IMO, you would be plain stupid to drive a S2000 and wait forever or having to drop two gears before you can accelerate. It's not about connecting with the machine, immediate acceleration, quarter mile runs, open track events, handling, low end or high end thrust...it's simply about what give you the most fun and help relieve the stress and or mundane routines of daily life. Failing to see this as to why we make different choices and have different preferences, would be a shortcoming.

[johnc]

Don't the NASCAR boys also rebuild their engines between every race?

 

After every race weekend. The engines have to last through 2 to 4 hours of practice, a qualifying session, and a 3 to 4 hour race. They probably put 6 to 8 hours and 750 race miles on the engine which I think is the longest of any top level professional race series.

[Drax240z]

But then again I'm not into swapping blown head gaskets or fretting over EGTs and AFRs...

 

You should be fretting over AFR's and EGT's regardless of your engine. And as far as blowing headgaskets goes... I'm not sure why this is percieved as a common issue with a turbo L6, but it really isn't.

[Guest JAMIE T]

I've been ignoring this thread for a couple of days.

 

I have owned many big cube NA cars. Most of them set-up specifically for drag racing, but still driven on the street.

 

I love them. Fast, easy to drive, awesome throttle response, etc...

 

I'm building what might be the epitomy of a high rpm, turbo lagging, high horsepower street car. It is my first OWN turbo car. I've driven alot of turbo cars, most of them heavily modified. The only own that wasn't was a first gen. Eclipse that was bone stock. It was the first turbo car I'd ever driven. I was impressed and actually liked the way it felt sort of sluggish then hit with the thrust. Other cars like a friends heavily turbo's B13 Sentra SE-R, was an absolute riot to drive as it pretty much hazed the tires anytime the rpm's went above 4000 . Again, a great feeling and it made for an awesome driving experiance.

 

My car I'm building now is a RB26 that will spin to 8500 minimum and has turbo's known to produce series horse power but will be alittle laggy. At some point, I'll give Pete P. a ride and we'll go back to Mike's and talk shop on the pro's and con's of turbo vs. NA and we'll drink alot of beers, then after we've sober'd up, we'll each drive our cars home and still be happy with them.

[JMortensen]

I'd just like to point out that stock L6 turbos rev to right about where my new GMC 5.3L V8 does, so "high revving turbo" is somewhat misleading. The GN turbo 6 peters out well short of where my new truck motor does.

 

And then you've got V8's with 6 speeds. Are these people lazy too? They took on a whole other gear, and that certainly that shows their willingness to do what it takes when it comes to shifting.

 

Bottom line for me is that I like a NA motor because I haven't yet found the turbo that doesn't have lag (I've driven the low boost high compression Volvos quite a bit too). I like a high revver because I know that in a NA motor there are 2 ways to make more power. More displacement or more revs.

[Mikelly]

...And Again, I'll point back to a thread above where I specifically state that ALL the issues you'd worry about with my old pushrod dinosaur, I'd worry about with your turbo motor... All the issues you guys worry about with your turbo motors, I'm not worried about..

 

Sure Drax, I'll have to be concerned about EGTs and AFRs, but not to such a level as in a turbo application... Say what you will but I think I outlined it well above...

 

It's called simplistic POWER. You add the sum of parts required to make a turbo motor run properly... then add the weight.... Then add the potential ADDED STRESS and ADDED potential FAILURE of those required parts...

 

Nothing wrong with turbos... JUst not my cup of tea...

 

Mike

[Scottie-GNZ]

After every race weekend. The engines have to last through 2 to 4 hours of practice, a qualifying session, and a 3 to 4 hour race. They probably put 6 to 8 hours and 750 race miles on the engine which I think is the longest of any top level professional race series.

I wo'nt bother to do the math since in either case it is amazing but the F1 engines might top that. New F1 regs say the engine must last for practice, 2 qualifying sessions and the race for 2 consecutive race weekends. Probably much less hours than NASCAR but those 3.0L N/As are being revved to 18-19,000RPMs and probably 1000s of gears changes during that span. Like I said, in both cases, simply amazing.

 

Upcoming rules will change the engine config from 3.0L V-10s to 2.4L V-8s and rumor has it some of the engines are already seeing upwards of 20,000RPMs on the dyno.

 

Did I change the subject? Sure did because this topic is headed down an endless path :D

 

[SBC_400]

After every race weekend. The engines have to last through 2 to 4 hours of practice, a qualifying session, and a 3 to 4 hour race. They probably put 6 to 8 hours and 750 race miles on the engine which I think is the longest of any top level professional race series.

 

it might be the most mile put on an engine in a race series, but in formula 1 the now have to run the same engine for at least two races, which is a lot of testing, qualifying and racing and that is on an engine that routinly goes through an RPM range of 8,000 to 19,000 with alot more load on it than a nascar engine.

 

and also, just becasue a race engine for any series has to be freshened, or rebuilt, does not mean that it is used up, it just has to be doen to remain competitive. a perfect example of that is Dale Coynes champcar team.

[Michael]

Well, I AM lazy!

 

When I get behind the wheel of my hobby-car, I want instant, brutal, uncompromising thrust, right off idle. I don’t want to work hard to find the engine’s power band. I work hard enough during the day – so, the last thing that I want is to “become one with the machine†or listen to its palpitating heart beat at 9000 rpm – and worry about sounds of rod bolts about to break.

 

My desire is for the torque of a steam locomotive, propelling the mass of a skate board. Actual racing results – like quarter-mile times – are irrelevant.

[pparaska]

but I still think laziness is responsible for not wanting to drop a gear every now and then. If you don't like shifting, maybe you should get an automatic?

 

Did I say I never shift down now and then? Not true. I just don't want to HAVE to shift down to get good acceleration. Again, not lazy, I just don't want my STREET car to NEED to be shifted down to accelerate well from cruise.

 

I don't want an automatic trans in my Z - that's for drag racing IMO, and I want to car to do much more than drag race, I won't give up shifting my own. You see I want it all - easy acceleration from cruise without HAVING to down shift, the brute force of accelerating after a down shift (if needed at the current cruise rpm), and being able to control the power delivery without a torque converter softening things or the valve body making decisions for me. I MIGHT have an auto if the converter was tight (or locked up much of the time) AND it had a full manual shift body - but then the auto wouldn't be downshifting for me, so it's no longer "automatic".

 

Nothing wrong with that, many people do it. My point is that while I do enjoy the instant response of say, a chevy 350, I wouldn't knock a turbo car just because it needs to be shifted more, becuase that doesn't bother me. (then again I'm still a "youngen" lol ) Like I said, it comes down to personal preference.

 

I would knock a turbo powertrain if it made me shift down from cruise to get decent, immediate acceleration, but that's not always the case - turbo drivetrains don't have to be that way - a smaller-than-bling-acceptable, low pressure turbo on a big enough, high enough compression engine will give a good bit of immediate thrust right off of cruise at a low rpm. Just the small turbo engines with the oh-look-how-much-boost, huge turbos are known for that. That's what I wouldn't want on the street, only at the drag strip.

[pparaska]

BTW, aren't NASCAR engines limited in displacement? Yes. 358 cubic inches (their's work afoot to lower this to 325 ci).

 

So how do you make more power if limited (an no power adders are allowed)? RPM That's why NASCAR engines rev to 9K+. They TOO are displacement limited. Sound familiar (Japan's 2 liter taxation law and it's result on smaller, higher revving engines, turbos, etc. from that country's makers.)

[pparaska]

Cyrus' post is quite helpful for those like me that have little to no experience with turbo motors but are toying with the idea of installing one. In other words the general statements have merit especially when you know that he is not just whipping it out, but instead has built and driven both types of drivetrains. His post combined with Mr. Kelly's first responce make this thread useful. The debating is poinless as Cyrus (although he doesn't say it) is obviously speaking of his[/i'] motor and not all Supra's, turbo's, octanes or whatever.....Rufus

 

Another point is (even though this seems to be a setup that's not done being tuned in), that the Turbo Supra engine's stock boost is something like half the boost that Cyrus is running (17psi). And the LS1 in his V8 car is stock, from what I've read. Hardly a fair comparison, but it wasn't supposed to be. It's just the two setups that cyrus has - must be nice to have TWO HybridZ's!!!

[crazy280]

you say tomayto, I say tomahto

[cyrus]

Can I cause trouble or what?! Lots of discussion. BUt heres the point

 

You can like what ever style engine you like but I am being realistic when I discribe the down side of the turbo car(lag,etc) vs big displacement. I have chosen that it is worth putting up with extra baloney on the turbo car to get more power. I think someone would be in denial if they thought two 300 RHP cars (identical wieght), one turbo, one NA, drive the same. Of course the NA car has better power delivery, but when the turbo can be boosted up then It may become worth it to deal with turbos when there is a power advantage.

 

This is point to understand the power CHARACTERISTICS of various engines, not to give opinions on which is better, because nobody will ever agree.

[pparaska]

Can I cause trouble or what?! Lots of discussion. BUt heres the point

 

You can like what ever style engine you like but I am being realistic when I discribe the down side of the turbo car(lag' date='etc) vs big displacement. I have chosen that it is worth putting up with extra baloney on the turbo car to get more power. I think someone would be in denial if they thought two 300 RHP cars (identical wieght), one turbo, one NA, drive the same. Of course the NA car has better power delivery, but when the turbo can be boosted up then It may become worth it to deal with turbos when there is a power advantage.

 

This is point to understand the power CHARACTERISTICS of various engines, not to give opinions on which is better, because nobody will ever agree.[/quote']

 

If you were to use two engines with the same average power or torque over the same sized rpm band, then we'd have a comparison to make. But your Supra engined Z is tweaked a good bit beyond stock to 406rwhp, and the LS1 is a stock 330 rwhp. Make them the same average power over say a 4000 rpm band (don't even have to be the same band) and we can make a comparison.

[crazy280]

Is 330 rwhp stock on an LS1? That is roughly 400 horses at the crank, which is roughly what a Z06 (with an LS6) is claimed to have by Chevy. If 330 rwhp is stock on the LS1, then what does the LS6 make stock at the wheels? I've never seen dyno sheets for LS-series SBC's, so if anyone can chime in that would be great.