Turbo vs. NA

[e30polak]

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.

I agree 100% with Rich! [peace]

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!

No, that's bastardization. :evilnah:

There are plenty of ways to properly bastardize a car though.....cough....s54....cough....e30.... :gotcha:

[blaquea8]

Ok...I know that this could turn into a massive flame-fest...but why is everyone so quick to go turbo and not look at doing a twin-screw supercharger? I know, I know, the age old "it robs power to make power" but considering the engine and the stock s14's lack of low end grunt - wouldn't a twin screw make sense? Fairly linear power boost over most of the power band seems like a good thing for a mostly street driven daily driver. I am not claiming any kind of expertise in the area at all...just been doing a lot of reading and comparisons and I find my self more intrigued with a twin screw over a turbo. For some reason it seems a little easier from a fabrication point of view and with the introduction of Mega-squirt it would seem fairly easy to get it tuned well (considering that was the major issue with previous SC kits of the past).
Is a supercharged S14 really a bad idea considering the materials available today? Seems to me as though there are a lot of factory supercharged vehicles out there that perform very well. So if one isn't looking for "drag strip" power and just wants a little more grunt through most of the power band - wouldn't the twin screw be a viable alternative to a turbo?

Let me know your thoughts. I ask this only because I have both a small stock turbo from a 1.8t VW as well as a rebuilt-as-new blower from an old Thunderbird SC and I have been going back and forth on which would be more "streetable" (streetable=passing power, stoplight to stoplight "spirited driving", canyon/mountain road twisties etc.)

[Ted B]

No flame fest ...

It's not a terrible idea, and it does make for a much easier exhaust solution. However, it still results in much of the cost of a turbo setup, but with less power. It makes sense for OE V8s and such because a power boost of only 25-30 hp/L makes for a big jump. That brings a 5.0L V8 from 375hp to 500+hp. Consumers will pay a premium for that. For a 100 hp/L S14, that same jump would bring 230hp to maybe 300hp for similar cost, and that isn't such an exciting jump for the cost and power/weight ratios typical of most street cars. Neither will it have as large a powerband as a turbo setup with the same peak power potential.

If one were going to explore this route, I'd recommend something capable of 350whp at max rotation speed in exchange for the trouble and expense, which leaves out the VW and Ford units you mentioned.

[///schwartzman]

What he said...

I think the twin-screw (Eaton style) charger adapted to a plenum would be a good setup, but for the hassles of bracket & plenum fabrication and max power output, it's not as feasible as a turbo systems flexibility for power upgrades... Osh has an s/c setup at AMS that is pretty reasonable.

[blaquea8]

No flame fest ...

It's not a terrible idea, and it does make for a much easier exhaust solution. However, it still results in much of the cost of a turbo setup, but with less power. It makes sense for OE V8s and such because a power boost of only 25-30 hp/L makes for a big jump. That brings a 5.0L V8 from 375hp to 500+hp. Consumers will pay a premium for that. For a 100 hp/L S14, that same jump would bring 230hp to maybe 300hp for similar cost, and that isn't such an exciting jump for the cost and power/weight ratios typical of most street cars. Neither will it have as large a powerband as a turbo setup with the same peak power potential.

If one were going to explore this route, I'd recommend something capable of 350whp at max rotation speed in exchange for the trouble and expense, which leaves out the VW and Ford units you mentioned.

What he said...

I think the twin-screw (Eaton style) charger adapted to a plenum would be a good setup, but for the hassles of bracket & plenum fabrication and max power output, it's not as feasible as a turbo systems flexibility for power upgrades... Osh has an s/c setup at AMS that is pretty reasonable.

Fair enough...thanks for the responses. I was under the impression that with the flow capabilities of the S14 head that the larger-than-needed Eaton M90 was actually easily capable of 250+ whp with the stock engine compression lowered appropriately and most of the other engine mods that any NA engine converted to FI would have. I remember reading awhile back of a Swede twin screw s14 (using and Autorotor aka Kenne Belle supercharger) that was around 400whp but couldn't get a good tune on it and went turbo instead (I don't think Mega Squirt was an option when that setup was done). But in my mind, the mounting braket and a plenum seem much easier to fab then the exhaust work needed for a turbo (but that's just my opinion...). Routing the belts/pulleys seems like the only "hard" part but if one get's rid of their A/C....

[///schwartzman]

I'd actually like to see an Eaton M90 or the larger one adapted to an S14, they are only @$200 in junkyards. Our belt system could stand to be upgraded to eliminate the p/s pump and alt. brackets maybe to a billet underdrive pulleys in a serpentine configuration. A custom intercooler / plenum probably would likely be best suited with a 76-90mm throttle-body (Infiniti Q45) and MAF than the ITB butterfly plates should help to get a good tune (optional of course). This combination should yield @270whp reliably and have excellent street manners. You can play with the s/c pulley diameter to squeeze a little more power from it but heat and efficiency become a consideration. A headgasket may be necessary, but the stock 9.8:1 should be fine for 7psi or .5 BAR of boost... Anything more I would install an intercooler, not an option. Weight would be about the same as a turbo setup although biased to the front drivers side.

Modifications:
Standalone EMS
MAF
Throttle body
Custom or modified plenum (with or without intercooler)
Remove ITB butterfly plates
Eaton M90 s/c with support bracket
Billet pulleys (optional)

[blaquea8]

I'd actually like to see an Eaton M90 or the larger one adapted to an S14, they are only @$200 in junkyards. Our belt system could stand to be upgraded to eliminate the p/s pump and alt. brackets maybe to a billet underdrive pulleys in a serpentine configuration. A custom intercooler / plenum probably would likely be best suited with a 76-90mm throttle-body (Infiniti Q45) and MAF than the ITB butterfly plates should help to get a good tune (optional of course). This combination should yield @270whp reliably and have excellent street manners. You can play with the s/c pulley diameter to squeeze a little more power from it but heat and efficiency become a consideration. A headgasket may be necessary, but the stock 9.8:1 should be fine for 7psi or .5 BAR of boost... Anything more I would install an intercooler, not an option. Weight would be about the same as a turbo setup although biased to the front drivers side.

Modifications:
Standalone EMS
MAF
Throttle body
Custom or modified plenum (with or without intercooler)
Remove ITB butterfly plates
Eaton M90 s/c with support bracket
Billet pulleys (optional)

Crap man...you took my thoughts right out of my head. That was EXACTLY what I was thinking of doing with my M3 when a buddy offered me the newly reman'd M90 as well as all the intercooler piping, throttle body etc. from the T-bird that he was planning to rebuild but ended up scrapping instead. Sold me all of it for $125...seemed stupid to pass up the deal at the time. This doesn't look all that hard to do and I am sure that the SC whine would sound pretty amazing added to the symphony that our engine already produces. Pics are of the Autorotor SC engine I spoke of earlier built by M3Jonas if memory serves me. READ MORE HERE

[///schwartzman]

Ok, I'll buy that...(not literally) I like the billet belt pulley solution. Was that system ever installed? Trying to visualize the radiator fitting... Not a fan of the plenum design but it looks like it will work.

You could fit the T-bird throttle inside the Q45 one (looks like the one in the photo), which when coupled with the huge MAF made by Nissan it will probably be pretty [email protected]$100 at a local yard. Huge gains...

[blaquea8]

Ok, I'll buy that...(not literally) I like the billet belt pulley solution. Was that system ever installed? Trying to visualize the radiator fitting... Not a fan of the plenum design but everything else looks like it will work.

You could fit the T-bird throttle inside the Q45 one, which when coupled with the huge MAF made by Nissan it will probably be pretty [email protected]$100 at a local yard.

The system was installed and a dyno registered 450+whp!!! But he couldn't get it to run consistantly due to tuning issues and adapting a chip was tough since they were all for turbos and Mega Squirt didn't exist yet (and most of the other options were WAY too spendy to make it worthwhile) so he eventually scrapped it and went with a turbo setup instead. Granted, the Autorotor unit is a bit more efficient compared to the Eaton but it's also a LOT more expensive! Size-wise though I think the M90 and the Autorotor unit were about the same. As far as the plenum goes - I seem to recall reading that he didn't put that much into it since it was now a pressurized system so the plenum didn't need to be as big as the stock one anything all that special. I would love to figure out a way to still use the stock one but I think there might be a space issue to do that. Looks-wise though that would be ideal.

The M90 is recommened for 3.0L - 5.7L engines but again, with the S14 flow characteristics, I think it could be a good match up. The ability to tune it correctly is the only big issue in my head. Eaton claims a "realistic 40%+ increase in power output" which I think would be pretty decent - since twin-screw blowers basically make boost off idle. I have also read that twin-screws are one of the most reliable FI systems that one can do. And for street applications I think the flatter power curve would be a lot safer. I also think the sound would be intoxicating! I wonder if one could even do a custom carbon plenum...hmmm...now THAT would really sound amazing!!!

I think the builder of the engine pictured is still on the S14.net boards but I don't know for sure since that build in the pics was from awhile ago. The intercooler pictured slipped in right in front of the radiator and there are pics of the fitment on that Swede forum I linked to earlier (although I think he used a 540i radiator for increased cooling). I had Google translate the page that I linked to and have read through most of it in an effort to learn from all of his troubleshooting.

The big draw for me the is to do something awesome but still unique. I know that sounds kind of weird...but I like trying out new things that haven't really been done a lot (at least not successfully). But it Mercedes can strap an Eaton onto the 4-banger found in the SLK230 then I don't see why one couldn't figure out a way to do the same to the S14. :evilnah:

Just takes time and $$$ :gotcha:

[Anders]

Jonas had massive reliability issues with that system and (finally) gave in a put a turbo on instead. To reach the power he did, the system put out too much boost down low and killed axles over and over again. He also destroyed the supercharger at least once.

[///schwartzman]

I can imagine... As soon as the pulleys start moving you're under boost pressure. What I can't imagine, having 2-3 spare axles, driveshafts or transmissions "just in case..."

[blaquea8]

Jonas had massive reliability issues with that system and (finally) gave in a put a turbo on instead. To reach the power he did, the system put out too much boost down low and killed axles over and over again. He also destroyed the supercharger at least once.

But for a street machine I don't think I would want that much power at all. It just doesn't seem very practical in my mind. 450+whp is too much. 250-300whp is all the more I think I would want for a semi-daily driver. But I don't want turbo lag either or the huge price tag of a full-on 2.5L engine build. Drop the compression a bit via pistons and a new headgasket designed for FI (ARP hardware of course as well) run modest boost levels and I don't think one would be breaking stuff like Jonas was.

[Anders]

I think your goals are totally reasonable and that it would be reliable. I think, though, that you'll end up spending a lot of money on the project for a powerlevel that you will get used to/get tired of quickly.

[Ted B]

250-300whp is all the more I think I would want for a semi-daily driver. But I don't want turbo lag either or the huge price tag of a full-on 2.5L engine build.

I have to agree with Anders.

No amount of planning makes this as inexpensive or straightforward as it seems, and the reward would be nominal.

FWIW, a 300whp turbo setup, properly done, wouldn't be laggy in the least and have torque that kicks like a mule. Subi STis and EVOs are examples of that. It would cost roughly the same as a smartly engineered 500-600whp capable turbo setup.

There's just no cheap, easy option. Getting real power means getting into it hands and feet, and having a budget and skills (or access to skilled help).

[Az in Oz]

You guys speak the truth :gotcha: