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Non VTEC high tech engine in NSX

Bigglezworth

Bigglezworth

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Feedback requested from those in the know.:confused:

First, before you contemplate any reply to this post - I politely ask you only respond to the question asked without being evasive, presumptuous, or simply rude which I've seen all too many times from many different members.

Second, yes - I did a search and read through many posts regarding the topic for this thread that occur "every 6 months" according to one member. While my question will be simliar in nature, I personally think it is still worth asking because a reasonable non-offensive response has yet to be provided. There was some great discussion on the subject across the multitude of threads, but unfortunately they contained a limited quantity of good feedback which was tainted by stupendous amounts of flaming and bashing.

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History
I've been a long time member on Prime for 3 1/2 years. I have a perfectly working flawless 75000km Canadian issued 1991 NSX which I've owned and tracked for 4 years. It has various enhancements from stock including Brembo/StopTech BBK, crate 6spd, clutch, exhaust, headers, coil over suspension, etc. Engine and CPU are entirely stock other from the bolt-ons noted. I also have a near new Novi2000 BBSC w/ AEM that I've had sitting on the shelf for the past 3 years that I am on the brink of installing this spring in time for opening track day in April. Our local autocross track has long straights that are used for the 1/4 mile drag racing and the higher power cars simply outrun the NSX no matter how good of a driver you are - period. Yes you can lessen the gap with improved handling and personal driving ability in the corners, but it never gets you caught up prior to the next long straight away where they pull away even more. It is not uncommon for an intermediate driver in our driving group piloting a ZO6, Viper, Ford GT, Novitech Ferrari, Porsche TT, etc., to hit 250km/h on the front stretch prior to threshold braking into turn one. The NSX only manages 210-215km/h on the same stretch prior to braking. I want to improve the raw performance of the NSX solely attributed to acceleration/power. Everything else on the ride is top notch and has been only marginally improved upon from that of Honda's engineers with items such as suspension, headers, etc. It's just underpowered for my situation and a close 4th in acceleration to the other three rides I own (GNX, 300ZX TT, S60R, NSX - in that order).

Background
I recently aquired a VERY limited production high power all aluminum 4.2L V8 that has state of the art technology in it and ample ability to hit 600hp and 600 ft/lbs of torque. This is leaps and bounds above the power levels attainable from the Novi2000 system I have here all ready to go. Obviously the BBSC bolts on and the engine swap doesn't even come close. I'm NOT interested in hacking apart an already well engineered car. Merely working within a set quantity of limits. I'm finishing a large extreme makeover on my house and will need something to quell the time I will have on my hands doing nothing other than sitting around on my ass. This could be a great project.

Question
Who has (or knows of someone who has) successfully completed a non-domestic engine swap in the NSX with a high tech V8 engine?? I've envisioned an NSX engine swap project and merely wish to know who if anyone has done ANY type of an engine swap from the stock VTEC motor? I don't care if it's a lowly Chev 350. It could be a high powered Stage II Buick V6. It could be a ZO6 engine. I'm not looking for anything specific. I'm more interested in what complications were encountered such as space, brackets, gearbox, axles, weight balance, etc.

Please be respective. Any constructive discussion would be welcome. Again - if you can't say anything nice - please don't. It does nothing short of spoiling the mood and I'll ask for the thread to be quashed by the moderator. Fair enough?:smile:

Thanks in advance.:smile:
Tim
 
I am not aware of any completed, sucessful, engine swaps... I have heard many stories, a few people have claimed to start the project, but nothing driving around.

It sounds like a great deal of hassle; I am sure you could, but why? Power is good, but one of the most appealing aspects of the nsx is its engine, which produces adequate power, and offers high levels of reliability. If you were to do this swap I see headaches, eventual parts breakage (eg transmission, axles, etc.), and non-existant resale value.
 
Geoff at FullRace (respected fabrication shop) started a swap, but I don't think it was ever finished. If I recall correctly, he was using an F20.

I personally have done a lot of swaps in a wide variety of cars and I think the NSX is going to be more difficult than most, due to the layout. Unless you are ready to really hack up the chassis to get a longitudinally mounted engine in there, you are facing some significant challenges. For starters, are you planning on mating it to the stock tranny?

I think you need to take your car to a good fab shop, tell them which motor you would like to use, let them look it over and see what they think is involved. I know of a couple of shops in Dallas that could do it and one or two in southern CA.

I hope this is at least slightly helpful and best of luck with your project.
 
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Unless that is some type of top secret Honda V8, I can't imagine the nightmare involved with doing the wiring.
I would also think that the engine would weigh more than the 3.0 and would disrupt the current balance of the car and negatively affect the handling quite a bit.
If I remember correctly didn't Honda intially try a different engine during development but chose the V6 for power, reliability, fuel consumption, size, etc.?
Good luck with your effort though.
 
Thank you to the feedback provided on this thread and various PM's. As I mentioned I appreciate the difficulty surrounding anything to do with engine swaps on the NSX very well.

To expand more on my level of sanity with this the 4.2L engine I eluded to is in fact an Audi RS6 engine. It's a very compact V8. Bore's are just shy of a 1/2" smaller than the VTEC allowing it to be relatively short. The length from the pullies to the transmission matting surface is a nominal 20" (the VTEC 17.5). I have a 6spd presently and know the 6spd is 2.5" longer than the 5spd. I have no doubt that the only possible method of getting the engine in with the honda tranny is with an adapter plate and the 5spd. It simply won't fit otherwise between the strut towers. The 4.2 is a 60 degree engine so it is certainly a lot narrower than the VTEC at only 29" across the top. It's also relatively close in overall weight (if anything it's added weight would offset my fat ass....) The engine currently has no turbos or EMS, but everything else is in tact from accessories to harness. I would add the turbos and associated plumbing to suit the requirements of the chassis. It would appear there being amble room once you work with a narrower engine to retain the turbos on the side of the engine and leave intercooling and exhausting behind the rear suspension. An aftermarket EMS would be desired from the stock anyways to address additional power opportunities and the logistics of having a manual tranny vs. the tiptronic from the Audi. I would be doing this project utilizing a spare rear frame that could be simply dropped and swapped out with the OEM set-up (that is what I'm referring to as being within limits). I have no interest in moding any suspension frames, panels, etc. to get things to work. I'm certainly not interested in cutting out the trunk, putting in an entire new rear subgrame, and slapping on a Porsche tranny just to say it could be done. I could just buy a Pantera or the like in the first place. I'm suspecious it will be a no go based upon what I've been able to determine so far. If the V8 doesn't work for this situation within a small amount of reason it will be left well enough alone for sure. I'm not crazy. Worse case I can utilize it in another car like a Nobel or the like. I could even get a Lotus and stuff it in there. :)

Tim


2002_Audi_RS65.jpg
 
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Have you figured out what you are going to do with respect to the transmission? If I recall, the crank on all Honda engines before the S2000 rotate the opposite direction compared to almost every other manufacturer.

-- Joe
 
I have two thoughts and dont intend them to be negative.

1) by another Audi/VW that this engine can be swapped into (A4?)
2) Sell engine to a fellow audi/VW racer and invest the income into the NSX motor.

good luck in whatever you choose.
 
JoeSchmoe said:
If I recall, the crank on all Honda engines before the S2000 rotate the opposite direction compared to almost every other manufacturer.

-- Joe
Click to expand...
I have NO idea on this and it definately would affect things.

Swift said:
I have two thoughts and dont intend them to be negative.

1) by another Audi/VW that this engine can be swapped into (A4?)
2) Sell engine to a fellow audi/VW racer and invest the income into the NSX motor.

good luck in whatever you choose.
Click to expand...
I actually thought about swapping with another Audi already. I can't legally import the RS6 into Canada due to Transport Canada regulations. Nothing states I can't import the parts and convert an A6/S6 ironiccaly enough. As far as the cost to mod the NSX motor - I have already gone down the road. I can live with it - I just don't see the bang for the buck with the Honda stuff like you see with other manufactures. Nature of the beast. It's not good news, and it's not bad news - just the news. :)

Again, if it simply doesn't work for a fun NSX project, it can be used for another fun mid engine project. I feel I got it a more than reasonable price to support any type of project. Hell - I've seen the 4.2 stuffed into a Lotus and that worked well.:wink:

Cheers
Tim
 
IMO

I think if it's to be attempted the most logical approach would have to be a complete subframe with engine from another mid-engine vehicle.

You may have to mod bodywork somewhat but it would be worlds easier than trying to fab all the parts necessary to fit a foreign engine in the existing engine bay.

With the subframe /engine combo, everythings in place for the most part.

Figure where your going to cut the car in half:biggrin:

Find your Subframe with engine..F360,GT-40, old 917

Place both halfs in Jig, align and weld.

Of course there will be much more to do but done this way, would save alot of the complexity that would be involved with trying to position engine,figure mounts, mate or manufacture tranny, axles, mount engine components ,electrical etc.

No matter what engine you put in or how you position it, there's really no way to know how it might handle. I would definetly lean toward a Longitudinal layout with engine centered to give yourself the best shot at a good result..

Good luck whatever you do...Be great if you could pull it off.
 

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Spooler said:
IMO

I think if it's to be attempted the most logical approach would have to be a complete subframe with engine from another mid-engine vehicle.
Click to expand...

I completely disagree. I'd much rather just position the motor where I want and and build mounts for it (not difficult at all) than deal with a much more complex structure. Having the complete subframe increases the complexity dramatically and increases the engineering challenges vs fabing up a set of mounts.

In addition, the odds of finding another mid-engine subframe that mates up to the NSX unit-body are very long. The odds of finding one that both fits and is a motor you want are astronomical.
 
David said:
I completely disagree. I'd much rather just position the motor where I want and and build mounts for it (not difficult at all) than deal with a much more complex structure. Having the complete subframe increases the complexity dramatically and increases the engineering challenges vs fabing up a set of mounts.

In addition, the odds of finding another mid-engine subframe that mates up to the NSX unit-body are very long. The odds of finding one that both fits and is a motor you want are astronomical.
Click to expand...

I Totally Disagree:biggrin:


Let's put it this way David...

If we had a race to do this in the most reasonable,efficient and cost conscious manner,

You to do it your way (Install V-8 in exsisting engine bay)

And my way (tearing off the entire rear end of the car to join a complete, intact, half a rolling chassis with engine).....

I think I would prevail.

Of course whatever subframe/engine I might find won't match up
perfectly. But if it's Mid engine there's a very strong chance I could mod it to work with a precision jig and expert welder....I might need to adjust wheelbase, and this gives me options. I expect subframe to allow me to service the engine easier also.

There are so many things to consider.

spooler
 
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Spooler said:
I Totally Disagree:biggrin: ....
If we had a race to do this in the most reasonable,efficient and cost conscious manner,

You to do it your way (Install V-8 in exsisting engine bay)

And my way (tearing off the entire rear end of the car to join a complete, intact, half a rolling chassis with engine).....

You would get creamed.
Click to expand...

How many oddball engine swaps have you actually done? I've got several under my belt and also have done a LOT of custom work with NSXs.

As far as your 'race' - custom mounts would take a full weekend of work, three days if there were severe problems. Based on your personal fabrication experience., how much time would you allocate to to fitting in a complete subframe? I could have the car running by the time you worked out your jig.

And, as far as cost, materials for mounts would run a couple of hundred bucks - how much would the complete subframe add to the cost of the project?
 
I've put a decent amount of thought into the idea of a non-C30A engine in the NSX. If you have a car with a motor in it already, I wouldn't consider any of these worth your time. I'm thinking about it because I have a shell without drivetrain. Replacing with another complete C30A would cost $7000-$9000. So for me, here are my contenders for swaps without chopping up the frame for something more exotic like a V8 /w 911 transmission.

Honda based:
F20B or H22A - 2.0L or 2.2L DOHC VTEC from a Prelude/JDM Accord.

Made 200hp stock. Thousands of 300+hp engines out there in accords, preludes and civics across the land with the help of a turbocharger.

Positives:
- Cheap & easy to source. ~$2500 gets you a complete drivetrain pullout.
- Plentiful aftermarket support for turbos.
- Cable shifter.
- Size shouldn't be an issue, I believe it would fit nicely in the NSX compartment
- Axles setup such should be easy to figure out.
- Wiring should be easy, since it's honda family and OBD1.

Negatives:
- Without forced induction, don't even think about it.
- 400+hp needs 14+psi of boost. Reliability becomes a question mark.

K20A or variation (2.0L VTEC RSX motor, and found in other Acura products now).

Positives:
- Engine sits same as the C30A.
- Cable shifter.
- Current, modern technology.
- Only option that has a 6 speed transmission

Negatives:
- Only makes 200-210hp stock. Unless you're planning to boost it, forget it.
- Forced induction is going to be expensive, and not at well tested or as cheap as the H22A choice.
- Swaps are expensive. $5000-6000+ due to high demand by ricers.
- Only came OBDII, expect a wiring nightmare.
- Add in another $5000 to build the motor properly to support 15+psi of boost and $5000+ for a turbo kit and electronics, this swap would bust your wallet fast.

Mitsubishi based:

4G63 Turbo (90-99 Turbo Eclipse), or 6G72 Turbo (91-99 3000GT).

Positives:
- Cheap & easy to source. ~$2500 gets you a complete drivetrain pullout for a 4G63, the 6G72 would be more like ~$4000.
- Boosted right from the factory, ~210hp for the 4G63 and 320hp from the 6G72TT.
- Plentiful aftermarket support to upgrade the stock turbos to 400+hp.
- Cable shifter again
- 4G63 should fit nicely in the NSX compartment. 6G72 may not, but it would be close.
- Lots of ECU tuning options.

Negatives:
- Mitsubishi motors aren't the more reliable.
- Axles setup would be custom
- Engine/transmission are on the opposite side compared with the C30A.
- Most of these engines come AWD. You'd have to mate a FWD eclipse/3000GT trans up to the motor in the NSX.
- Engine wiring would be a PITA to mate to the NSX chassis wiring.

Toyota:

3SGTE, the 91+ MR-2 2.0L Turbo engine.

Positives:
- Cheap & easy to source. ~$2500 gets you a complete drivetrain pullout.
- Boosted right from the factory, ~225hp stock.
- Plentiful aftermarket support to upgrade the stock turbos to 400+hp.
- Cable shifter again
- Engine is on the same side as the C30A, should fit easily in the compartment.
- Comes with a strong mid-engine transmission, no need to convert to FWD from AWD like the Mitsubishi options.
- Lots of ECU tuning options.
- Light, and very powerful. They used these to replace the 2JZ in the JGTC touring cars. 600hp is attainable.

Negatives:
- Axles setup would be custom
- Engine wiring would be a PITA to mate to the NSX chassis wiring.


GM - Northstar V8

Positive:
- heck, if they can fit it into a Fiero, maybe we can get it into an NSX.
Negatives:
- It's a GM. This is the equivalent of automotive heresy. The thought of this makes my stomach churn, but it has to be thrown out the as an option since it's compact, 300hp and FWD.
- The motor is a lemon, and I don't think you can get it in a manual transmission.

Constructive criticism or additions welcome!
 
How many oddball engine swaps have you actually done? I've got several under my belt and also have done a LOT of custom work with NSXs.

None...but I didn't Invent Subframes. I just know that many cars utilize them and thought it could be a possible solution.

As far as your 'race' - custom mounts would take a full weekend of work, three days if there were severe problems. Based on your personal fabrication experience., how much time would you allocate to to fitting in a complete subframe?

It depends what resources I have at my disposal..vacility to work, manpower,donar car. If I had my own facilty as you seem to have I think I could have both cars prepped fairly quickly for the joining.

I could have the car running by the time you worked out your jig.

GET Real..you'd have so many details to work out i'd be Scary. After I finish the joining, maybe a week at my local NASCAR service facility:biggrin: .. My car will not only run..it will shift,fuel,cool and be close to operational because in utilizing Mid engine, shift linkages/mechanism will probably be adaptable to stock tunnel. What the hell are you going to do about transmission!??

And, as far as cost, materials for mounts would run a couple of hundred bucks - how much would the complete subframe add to the cost of the project?

Again , your works just begginning if you happen to sqeeze it in there so don't give me this couple hundred bucks crap.

Yes ..my biggest expense would be the Donar car, Frame jigging and subsequent enginnering calculations, plus fitting Body Panels to new structure.

Yours would be trans and running gear and tons of trial and error trying to figure out where everything will fit.

Maybe it's a wash:biggrin:

No hard feelings
Spooler

__________________
 
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Spooler said:
Yes ..my biggest expense would be the Donar car, Frame jigging and subsequent enginnering calculations, plus fitting Body Panels to new structure.

Yours would be trans and running gear and tons of trial and error trying to figure out where everything will fit.
Click to expand...


That's my point - its not "tons of trial and error.' You position the drivetrain where you want it (this is actually the trickiest part, as you have to everything aligned true. If you have ever seen a race car jig, you know how many plumb lines and levels are involved). Once that is done, fabing a set of mounts to keep it there is not difficult. Anyone who couldn't sort the mounts out in a day shouldn't even be talking about complex fabrication work.

As I have mentioned before, Geoff at FullRace has played this game already. Anyone who is going down the same path should talk to him and see what he thought the major issues where. I believe his shop is in Phoenix.

http://www.full-race.com/

Spooler, I am not trying to be combative, I just don't see how adding complexity makes things better. Perhaps if you could help me to understand how you would insert the donor subframe......are you planning to weld it directly to the firewall? The rear suspension crossmember? Are you going to cut out an entire section of the unit-body? If so, you are now down to almost no realistic donor options as the subframe would then have to be aluminum. Keep in mind, the nsx is not like a Pantera or some other old-school chassis. There are no true frame rails. If you could explain in a bit more detail how you would accomplish this, I might be able to add more constructive input.
 
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Spooler, I am not trying to be combative, I just don't see how adding complexity makes things better. Perhaps if you could help me to understand how you would insert the donor subframe......are you planning to weld it directly to the firewall? The rear suspension crossmember? Are you going to cut out an entire section of the unit-body? If so, you are now down to almost no realistic donor options as the subframe would then have to be aluminum. Keep in mind, the nsx is not like a Pantera or some other old-school chassis. There are no true frame rails. If you could explain in a bit more detail how you would accomplish this, I might be able to add more constructive input.[/QUOTE]

Dave..based on what you've described bout NSX chassis, it may not be possible..I admit..I'm shooting from the hip, having never really seen the area that I want to attach to.

I've been looking for Good pictures of the Naked chassis to study and possibly Photoshop a potencial attachment point (if available) but I can't find any pics that are suitable.

I'm going to try and look threw some convertions to see if I can find pic of naked firewall/lower chassis area..so I can understand what I'd have to work with.

spooler
 
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I have been unable to find suitable photo's to study the naked firewall and extrusions beneath it but it doesn't matter.

After making this crude drawing I realized that although a subframe could probably be made to work, it would be extremely complicated as David said.. and to use existing donar unit would make it more so. I would instead go for a custom built tubular unit fabbed for the LS1. this is getting expensive:biggrin:

Without even having seen it and judging by descriptions I can already tell that my only hope of finding attachment point is to create it by joining a large pre-cut alum plate to fire wall and adjoining extrusions. I would then create mounts for a bolt on application..be very crude like a race buggy (tubular subframe) but..you could put anything the hell you wanted in there:biggrin:

Plate depending on material thickness required could add excess weight and could be very dangerous as well (stessing area's that they were not designed for)..no good.... But, if you could add strenghth to the overall structure with custom roll-cage and have the firewall plate tie into it, that may be a solution.

Althought the drawing not to scale , it shows that a longitinal posistion could work but wheelbase would have to come way out to compensate for lenghth of V-8 plus fan belt. Engine must be sideways for drop in using oem wheelbase...Body work would need modification for longitinal position.

I quit:tongue:
 

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