Turbo vs. NA

[Ted B]

Cool - So why didn't BMW just make a turbocharged S14's to race against Ford Sierra Cosworths back in the day...

...And how many modified turbocharged E30 M3's do you know that have outstanding racing success, even nowadays?

... Most race E30 M3's stay N/A because of regulations, but also because owners understand the benefits of lightened frontal weight, chassis balance and high reving engines.

Did racing rules back in the day allow turbochargers to be fitted to cars not originally equipped with them? I don't think so.

There is no evidence that turbocharging an E30 M3 would deprive it of 'outstanding racing success' as you surreptitiously implied.

Racing E30 M3s remain N/A due to regulations, end of discussion. Most cars represented in this forum are upgraded street cars, not stripped down race cars restricted by rules. Your suggestion that turbocharging an M3 would upset its handling and limit rpm potential is both false and surprising. Perhaps I would benefit by converting my quick-spooling 600whp EVO VIII to NA?

You're entitled to your opinion, but said opinion is biased by romance ('soul and purity'). Meanwhile, the sheer performance of competently engineered forced induction cars (both production and race) around tracks ranging from Nurburgring to WRC to Time Attack circuits is overwhelmingly self evident.

[chutrain]

I think people are confusing a mild turbo setup versus something that is built for pure
power. A well developed system putting out reasonable power with a smaller turbo
with very little lag is what would make this attempt by VAC or anyone a good path.
I love my little Suby Legacy 2.5GT with a turboback and flash as it is very driveable
and plenty of get up and go without drawing too much attention. Obviously putting
a much bigger turbo will change the characteristics significantly, which I believe is
what this debate is about.

There are so many different levels of purists these days, especially pertaining to the
S14 motor. You have your only rebuild with the exact same parts that came in the
2.3L, the modify 2.3L, the 2.5L guys and those that go full on with it, the swap
guys, and in this case those looking into putting a turbo. I think this falls right
between the different categories.

The characteristics will change slightly in terms of handling, but let's be honest,
most of us will never see the full potential of these cars. Most are street machines
with owners exhilarating themselves with some nice pulls and highway runs. The
likelihood of them tracking them is few and far between when working out the
numbers. For the track, you can argue the guys will want to have a well balanced
car that you can be on the gas as much as possible and having a linear power
delivery. But this also brings back a small turbo can still work pretty seamlessly with
a well balance package.

In the end, this is up to the owner. Will VAC sell kits if they keep it reasonable? I
think so. Would those sway the "true" purists? No. Would this make those swap guys
put back their S14 and turbo? Probably not. All I know is that for a street car like
mine, and knowing the benefits of adding a bit more power with the subtle hint of
lag, I think I can live with that.

[Ted B]

Exactly.

The scope of this effort is to give more oomph to street cars, to put them on a better footing with more modern hardware in common situations, and eliminate the typical shortfalls of dealing with a NA 4-cyl in a full-weight street car - without resort to expensive, torque-absent options that need to be worn out at high rpm to give reasonable performance. No one here is going to be fooled into thinking this would be something that's going to enable them to win Time Attacks, or be close to par with top-tier turbo engineering efforts. It's just an alternative that fits with 21st century thinking.

[Newera]

Did racing rules back in the day allow turbochargers to be fitted to cars not originally equipped with them? I don't think so.

There is no evidence that turbocharging an E30 M3 would deprive it of 'outstanding racing success' as you surreptitiously implied.

Racing E30 M3s remain N/A due to regulations, end of discussion. Most cars represented in this forum are upgraded street cars, not stripped down race cars restricted by rules. Your suggestion that turbocharging an M3 would upset its handling and limit rpm potential is both false and surprising. Perhaps I would benefit by converting my quick-spooling 600whp EVO VIII to NA?

You're entitled to your opinion, but said opinion is biased by romance ('soul and purity'). Meanwhile, the sheer performance of competently engineered forced induction cars (both production and race) around tracks ranging from Nurburgring to WRC to Time Attack circuits is overwhelmingly self evident.

Had BMW wanted to, they could have turbocharged the E30 as a production car, to homologate it for touring car racing - but clearly they didn't feel the need to and went on to have the most successful touring car racer ever campaigned.

I'm not saying turbo is necessarily bad, but there may be better choices to enjoy turbocharged performance than taking an E30 M3 and doing all the work to make it turbo. Perhaps that's why you chose an Evo instead of ripping your M3 apart and turbocharging? As for revs, the highest a full tuned forged 4G63 engine will go to safely - fully built is around 7,800 - 8,000. Compare to a fully tuned S14 N/A engine making around 280 bhp.

Back to what I'd judge the best bang for buck turbocharged car - Getting a healthy FD3S RX-7, adding just an ECU, boost controller, front pipe and exhaust with a larger intercooler and radiator will give 350 bhp at 0.9 bar. And the lowest levels of turbo lag for reasons explained prior.

There's no internal changes necessary on a rotary up to power of around 450 bhp, thereafter it's mostly porting to allow more air & fuel to be pumped through for higher power. No cams, no pistons, no conrods, valvetrain, etc. On a 13B rotary you get 350 bhp with just a few day's effort or less and only a fraction of cost.
Compare 13B tuning with what it would cost in terms of money and time to turbo an S14 to make the same power. Around 5+ times as much!

I realise some people want to keep their M3 and enjoy tuning them, but some may want to consider their options before spending $15K + on turboing when they can get an entire other turbo'd car and greater enjoyment for their money elsewhere. I'm not saying E30 M3 turbos are bad, but there are better choices available.

Sure, there's romance in my appreciation for N/A tuned engines...

I know it's mega tune and not what we're discussing with regard to VAC's intentions, but for interest here's an 800 bhp GT-R I drove in 2004 (With a friend driving my RX-7).. It was supremely quick, but on tight mountain roads little N/A screamers leave it standing. http://www.youtube.com/watch?v=y7qnLtjmcnQ
Here's the RX-7 on standard twin turbos, around 2003, back in the days when street racing in Japan was still loosely tollerated on weekends. http://www.youtube.com/watch?v=VDHDZk-FiNI

[chutrain]

The thing is that for most people, the E30 M3 is their one and only toy. They do
what they can to make it quicker, obviously different interpretations. Having
something that came from the factory with built on turbo is different than one
having a custom setup bolted on. Let's face it. A manufacturer spends millions of
dollars on R&D before a car is made roadworthy. Just won't get it, even with a "bolt
on kit."

I would love to get a FC or FD. Just a fun car to have and putting minor upgrades
does yield a lot of power vs. cost. Just the nature of the beast when tuning a turbo
car. Just to quiet this debate, you really can't compare a FD to an E30 M3 with
turbo kit. Just isn't fair. It's like comparing a Veyron with a car with 4 turbos bolted
onto it and saying it's just as fast. Yes, an outlandish comparison. If we wanted a
fast car that can take on today's technology, then we are all jaded.

In terms of the GT-R vid, didn't watch it, but there is such thing as an overpowered
car for certain situations. You give it a nice open track and it'll decimate anything
in its path. You put it on a tiny little track and a Mini Cooper could hold its own.

I just think we are going about this the wrong way. A vendor is looking to develop a
system of a 20+ year old car. We should be happy and offering suggestions on how
to tackle it, rather than comparing a factory turbo car vs. a fabbed up kit. Just how
I see it at least.

[Newera]

The thing is that for most people, the E30 M3 is their one and only toy. They do what they can to make it quicker, obviously different interpretations.

Just to quiet this debate, you really can't compare a FD to an E30 M3 with
turbo kit. Just isn't fair. It's like comparing a Veyron with a car with 4 turbos bolted
onto it and saying it's just as fast.

A Veyron & a highly tuned car will have vast gaps in cost comparison.
A used FD or $15K + on turbocharging an E30 M3 is roughly the same cost.
I'm just thinking outside the box and sharing a devil's advocated stance.

I agree with much of what you say in your last 2 posts above, Chutrain - turbocharging's not for everybody like you say. If VAC can offer a good package it might find fans and I wish them all the best with it.

[e30polak]

The thing is that for most people, the E30 M3 is their one and only toy. They do
what they can to make it quicker, obviously different interpretations. Having
something that came from the factory with built on turbo is different than one
having a custom setup bolted on. Let's face it. A manufacturer spends millions of
dollars on R&D before a car is made roadworthy. Just won't get it, even with a "bolt
on kit."

I would love to get a FC or FD. Just a fun car to have and putting minor upgrades
does yield a lot of power vs. cost. Just the nature of the beast when tuning a turbo
car. Just to quiet this debate, you really can't compare a FD to an E30 M3 with
turbo kit. Just isn't fair. It's like comparing a Veyron with a car with 4 turbos bolted
onto it and saying it's just as fast. Yes, an outlandish comparison. If we wanted a
fast car that can take on today's technology, then we are all jaded.

In terms of the GT-R vid, didn't watch it, but there is such thing as an overpowered
car for certain situations. You give it a nice open track and it'll decimate anything
in its path. You put it on a tiny little track and a Mini Cooper could hold its own.

I just think we are going about this the wrong way. A vendor is looking to develop a
system of a 20+ year old car. We should be happy and offering suggestions on how
to tackle it, rather than comparing a factory turbo car vs. a fabbed up kit. Just how
I see it at least.

You took the words out of my mouth. I agree totally with this statement.

Choice of components and tuning will have to be chosen carefully for this kit to be worth anyone's time. I don't think it will be done cheaply, or on the first blue print, but we'll see what the boys at VAC can do.

[Ted B]

Had BMW wanted to, they could have turbocharged the E30 as a production car, to homologate it for touring car racing - but clearly they didn't feel the need to and went on to have the most successful touring car racer ever campaigned.

...Perhaps that's why you chose an Evo instead of ripping your M3 apart and turbocharging?

...As for revs, the highest a full tuned forged 4G63 engine will go to safely - fully built is around 7,800 - 8,000.

What BMW did or didn't do with a stripped out DTM car some 20 years ago has little to do with what I desire from my street driven E30 M3 in 2010.

Your information regarding the durability of 4G63s is incorrect. My own full-tuned, forged engine is one of many documented examples that routinely sees 9000rpm without longevity issues (disassembled and verified), while dedicated drag efforts are proven to hold up well to 10,000 rpm. Even factory engines have demonstrated undiminished reliability when an 8200rpm limit is observed. See the Evolution forums for loads of proof.

FYI, 'ripping apart' and turbocharging my E30 M3 is exactly what I'm doing. A comprehensive, frame-off performance rebuild, upgrade, and turbocharging effort is presently underway. If it turns out anywhere near as amazing as my 600+whp EVO has, I'll be more than satisfied.

[Newera]

Cool, I guess Jun Auto, Tomei, etc. don't know an awful lot about tuning 4G63's - which is why they limit their time attack cars to around 8,500 rpm limits I've found in Japanese publications before posting.

We'll have to agree to disagree on rev limits of 4 cylinder turbos & longlevity.

Enjoy the build & have fun Ted.

[Ted B]

What Jun and Tomei offer doesn't represent the state-of-the-art on these shores, so pardon if I defer to my own experiences (and those of hundreds of others) instead of what you read in a Japanese publication. Don't pretend to be a 4G63 expert Newera. You aren't.

[Newera]

Never did say I was an expert in 4G63's, Ted but I do respect knowledge of tuners such as Tomei & Jun who have been building very high power turbo motors for over 2 decades. Anyways, let's agree to disagree and let this thread go back to topic.

[Az in Oz]

So we've heard some good points on both sides of the discussion and witnessed the passion people have for their own causes.
This thread was started to bring forwrad the thought of an affordable turbo kit for the S14......... so it should go back on that path.

I would love to see this thread continue in the Forced Induction section

Aaron

[Az in Oz]

Good work Rich

[///schwartzman]

Ahhhhh... Well I'll throw some suggestions out there for a turbo wishlist for VAC or others going this route. Kits should be offered with and without turbo, WG, & BOV's, primarily for "made to fit tubing" To negate the weight argument kits would be made where the A/C equipment should be removed.

Two styles of turbo manifold: (4-6wk. lead time)
Top mount & low mount w/single and twin-scroll options

Popular turbo flanges: disco-potato, T3-T4, V-Band you get the idea...

Air to Air & Air - H2O Intercooler (test fitted)

Turbo and I/C setups for 350/500/650hp levels
*for longevity, turbos should be ball-bearing & oil / H2O but as long as popular flanges are made available thrust bearings can be used... Lag will suck though.

And finally, to whoever chooses to embark on this mission, don't gouge your potential market for your R&D costs (basically, chalk those up) and more than a 40% markup on costs... It will likely result in vain efforts to post on a website. I believe this can be done reasonably, it just has to be packaged properly without being a ripoff.

[///schwartzman]

I just got the "turbo is cheating" comment, wasn't the same said of nitrous, IMO every mod has it's place...
Cheating is envying a motor in another car and cramming it into a car doesn't belong. Ha ha!