prototype Eaton M90S based S/C system

[ken sampson]

did you stock radiator fit back in were it was factoy installed? if so do you have the part# for the setrab coolers?

 

[robr]

I think you'll find much more interest when the kit is available and has proved itself as being bulletproof. I suspect many of us are interested in lower priced forced induction as long as it's reliable. A lot of us simply aren't swimming in money, so the current options are just outside our means, so your product is of great interest.

 

[Mark911]

did you stock radiator fit back in were it was factoy installed? if so do you have the part# for the setrab coolers?

Yes, the stock radiator would haved bolted in fine. However, you would probably want a bigger (dual) fan to keep the IC water from getting heat soaked during stop and go traffic. You'll need to wire it up so that it runs at low or high speed during these conditions. The stock fan controller works on engine temps, not IC water temps. I'll need to look at my receipts to find the heat exchanger P/N, or I can just count the number of rows. If you go with the two large Setrabs or Earl's you'll need to use hood pins as there's no room for the stock hood latch mechanism. Mark

 

[PKim]

Mark,
I first want to commend your work, looks to be a very nice setup. I know that there was a lot of time and effort in pursuing such a risky venture. I think, like myself that there are many ppl in the nsx community looking for was to increase the hp in their nsx. But many are weary because of short comming that some FI system had in the long run, I don't want to name, names. If this can be a proven SC, with long term reliability, I think there will be long list of ppl interested, and your efforts will be rewarded. With the fact that there may be no next gen NSX, there's going to be many ppl wanting to upgrade the existing nsx to compete with the other supercar. For me I have been on the fence for FI and the only one that I would consider is the CTSC, for its reliability, plug/play format, and the fact that it is CARB legal. If I had the money FX500 would definately be in the future. If you have the time I would love to see your work first hand, I'm in the San Bernadino area, PM me if you want.

Paul

 

[robr]

agreed, if money was no issue, fx500 would be the way to go. since money is an issue, the current solutions are too expensive in general and for the amount of additional performance they provide (ie, not enough bang for the buck for me). as mentioned in the above post, the only current SC solution i'd consider (if i didnt feel the $$ was too much), is comptech because as far as i'm concerned, it's the only thing out there reliable enough to make me feel comfortable, even though it probably provides the least amount of additional HP of all the solutions available.

 

[NetViper]

Mark,

Could you not also produce a low-boost turbo solution for roughly the same $$? I am not sure if you are a specialist in SC or what, but if you could create about 375whrp out of a low boost turbo, I think that would also be a very very attractive option.

Nonetheless, thanks for supporting the nsx community. We all appreciate it.

 

[Ojas]

Could you not also produce a low-boost turbo solution for roughly the same $$?

The way I read it, Mark is saying the low-boost system would be similiar to his current setup except no intercooler and stock intake manifold:

However, if I reduced the boost to 5-6 psi, tossed the IC and used the stock intake manifold the cost comes down significantly. With some vendor support (better prices), I think I could offer a bolt on system for under $5.5K.

 

[NetViper]

The way I read it, Mark is saying the low-boost system would be similiar to his current setup except no intercooler and stock intake manifold:

Yes, but he is talking about SC, I am talking about a low boost turbo.

 

[Ojas]

Yes, but he is talking about SC, I am talking about a low boost turbo.

Oops. My bad. :redface:

 

[jgtcnsx]

if you guys are looking for reliability superchargers are the way to go.

 

[robr]

we're driving an NSX, of course we want reliability . though i believe a properly designed turbo system can be just as reliable.

my driveway has always had a car with a turbo parked in it until i sold off my 300zxtt a few years back (unless you count when i lived at home and drove my mom's plymouth horizon back in the early 80s ). i've never had a turbo go or engine explode, even on wastegate modded cars (i lost a main bearing on my 300zxtt, but it wasn't turbo related and i used the opportunity to build it into a 450hp rwhp zxtt). i know the nsx wasn't built with a turbo in mind, but i still think it can be as reliable as a SC if done properly.

 

[jgtcnsx]

we're driving an NSX, of course we want reliability . though i believe a properly designed turbo system can be just as reliable.

my driveway has always had a car with a turbo parked in it until i sold off my 300zxtt a few years back (unless you count when i lived at home and drove my mom's plymouth horizon back in the early 80s ). i've never had a turbo go or engine explode, even on wastegate modded cars (i lost a main bearing on my 300zxtt, but it wasn't turbo related and i used the opportunity to build it into a 450hp rwhp zxtt). i know the nsx wasn't built with a turbo in mind, but i still think it can be as reliable as a SC if done properly.

the reason why turbos arent reliable as superchargers is cause they use the hot exhaust fumes to spin the turbine. on small street turbo systems they create higher back pressure then they would the bigger turbos. superchargers on the other hand dont. nsxs are higher compression which means the run leaner, which is less exhaust fumes to spool the turbo. maybe you havent had any problems with your 300zxtt but that comes from the factory with the turbo.

 

[PaynNSX]

if you guys are looking for reliability superchargers are the way to go.

the reason why turbos arent reliable as superchargers is cause they use the hot exhaust fumes to spin the turbine. on small street turbo systems they create higher back pressure then they would the bigger turbos. superchargers on the other hand dont. nsxs are higher compression which means the run leaner, which is less exhaust fumes to spool the turbo. maybe you havent had any problems with your 300zxtt but that comes from the factory with the turbo.

I am currently a huge fan of my personal supercharger based system. However, both of these quotes are gravely false! Turbochargers and superchargers can both have absolutely the same reliability if designed properly. Companies like Mercedes have gone both ways with enormous success – Mercedes CL55 5.5L V8 (supercharged) vs. Mercedes CL65 V12 (turbocharged).

Turbos rely on exhaust pulses (not fumes) to spin the turbine and backpressure measured in the exhaust housing of the turbine side has little to nothing to do with reliability, but more so to do with how efficiently the system is working. Exhaust side backpressure data when compared to boost can help tremendously when properly sizing a turbo for a particular application. This is a terrible reliability comparison between the two types of systems.

Leaner air/fuel ratios are in no way a result of higher compression – they are a result of programmable fuel injection and timing mapping. A lean (or rich) air/fuel ratio does very little to affect boost. Actually opposite of what you described, a little leaner air/fuel (hotter) will often help with spool up response on turbo based systems.

Just my .02

 

[NetViper]

I am currently a huge fan of my personal supercharger based system.

Is that a modified BBSC? What is the cost on that? Does it still make 90% of its power above 5500 RPM?

 

[Mark911]

Turbos rely on exhaust pulses (not fumes) to spin the turbine and backpressure measured in the exhaust housing of the turbine side has little to nothing to do with reliability, but more so to do with how efficiently the system is working. This is a terrible reliability comparison between the two types of systems.


Indirectly, exhaust gas backpressure CAN affect reliability if the engine was not designed for its thermal affects. For example, exhaust ports and valves run higher peak and average temperatures. If the coolant passages and exhaust valve material aren’t designed to handle this thermal loading, problems can occur (localized coolant boiling, valve damage, etc). In addition, the cylinder head to block interfaces see more stresses due to the constant thermal cycling between the upper and lower temperature extremes. This might lead to head gasket or other related sealing problems. The exhaust manifold itself must be a very robust part to handle all the additional thermal and structural stresses involved (structurally -assuming the turbo bolts directly). These are not difficult problems to overcome if the manufacture designs the system with the thermal loading requirements in mind, but I assume we’re talking reliability as it pertains to an aftermarket retrofits.
In my opinion, the reliability of the individual components that make up most aftermarket kits is quite good, turbo or SCed. Most are simple mechanical devices that if properly feed and maintained are pretty bulletproof (exception being those crazy Aerodynes). The problems usually stem from the engine management system (if any) or the tuning thereof.
The Comptech system has a great reputation because its engine management (actually fuel management) is so simple. Most folks probably only run at boost for brief moments (stop light GPs), so for the most part the Comptech is running just like stock with all the bells and whistles associated with the great stock ECU. Can’t beat that! At boost, the Comptech simply fakes out the Map Sensor and manipulates fuel pressure, one parameter the stock ECU doesn’t monitor as it’s constantly self-checking itself. And low and behold it works, up to a point. That point being when the owner wants to start upping the boost. That’s when the limitations (and problems) associated with the Comptech start. But for 90% of Comptech owners, the stock setup is fine and they are happy.
Then there are piggyback systems that take engine management to the next level. Problem is that the Honda ECU is a smart bastard and will soon begin to “make adjustments” on it’s own based on its original programming. Pretty soon you end up just scratching your head and chasing your tail. I’m sure there are ways around this as well, but it’s a learning experience, which is why some systems need more development time then others.
Then there are those of us that beat our cars on the track and need a bit more “insurance”. We need to be able to consistently trim timing and alter mixtures just to be on the safe side. We also want the option to go hog wild on boost and possibly even blow up our engines (it’s a free world). Standalones are the answer today, but you’re going to loose some of that great Honda R&D when not at boost. Drivability, cold startup, idle, fuel mileage, all those things we took for granted no matter what the conditions (in the snow at 6000 feet or in the hot desert at –200 ft) will be compromised to some degree depending on the competency of your tuner. Good tuner, happy customer. Bad tuner, unhappy customer and maybe a big repair bill.
The only FI system reliability issues I can think of that differentiate between systems are as follows:
Turbo;
1) Faulty signal to turbo wastegate could result in the boost spike from hell – not good, possibly BANG!
2) Plugged/restricted turbo oil return line could fry turbo bearings – not good
3) More heat energy going into oil system, probably higher ave oil temps – not too good in general
SCer
1) More intake area under vacuum makes them more suspect to air leaks at various interfaces and leaning issues, usually at idle – not good (note, Comptech is very good in this area because of it’s integrated manifold).
2) If any major air routing component between blower and the stock manifold should fail, the engine will act as if throttle is open to the extent of the vacuum leak – not good at all but unlikely
3) More tension on the crank/alternator pulleys due to SC belt could result in bearing failure (long term) if tension is kept unnecessarily tight – not fun

Other items like using the stock vs aftermarket airbox/air cleaners can have an affect if dirt gets into the engine. This is designer dependant, however.

Just a few thoughts, mark

 

[PaynNSX]

We are definitely talking reliability as it pertains to an aftermarket retrofits.

I was trying to correct a couple points jgtcnsx brought to the table so as not to confuse the issues within the community. Mark, I agree with your points about possible backpressure effects in a turbo forced induction example, but I think out of 100 items for the community to be concerned about this would rank in the lower 5. I am very glad you are strongly emphasizing management with your kits.

Honda has developed very FI receptive motors (not on purpose) over the last 2 decades, and the NSX is no exception.

NetViper - Other than adding an EMS to my BBSC, my car ran high 11 second quarter mile times right out of the box from Mark Basch. Over the last year I've been making some considerable changes to other supporting mods but the core system is right off of Basch's workbench.

 

[peiserg]

mine does make most of it's power above about 4700, but in no way would i classify it as "90%". i don't really know how ot quantify this in real terms, but on my dyno my car took off above baseline as early as 2500 rpm or so, and widened the gap rapidly until redline. the ctsc made a reliable 10-20 more until 4500, then progressively less.

 

[NetViper]

NetViper - Other than adding an EMS to my BBSC, my car ran high 11 second quarter mile times right out of the box from Mark Basch. Over the last year I've been making some considerable changes to other supporting mods but the core system is right off of Basch's workbench.

So you are taking the original $6500 kit and adding a $1200 AEM and getting 11's? Is that on a 3.0 or 3.2? Sounds impressive.

One thing I really like about Mark911's design is that he created a LOT more low-end Tq than stock or the BBSC.

I would love to get a ride in a properly tuned BBSC one day.

 

[jgtcnsx]

Turbos rely on exhaust pulses (not fumes) to spin the turbine and backpressure measured in the exhaust housing of the turbine side has little to nothing to do with reliability, but more so to do with how efficiently the system is working. Exhaust side backpressure data when compared to boost can help tremendously when properly sizing a turbo for a particular application. This is a terrible reliability comparison between the two

backpressure causes what is called reversion. reversion is when the hot exhaust gases gt pumped back into the engine during the overlap period.reversion can cause the engines internal to get excessivly hot as cross flow of the cold intake charge during overlap is one of the ways an engine cools itslef internally. hot internal parts can trigger uncontrolled combustion and engine-destroying detonation. because of this it is not a good idea to jack up the boost on a small, high-backpressure turbo. yes it can be mapped to run good on a nsx. but the question is. what is the point of choosing a turbo over a supercharger if you cant jack up the boost? the nsx alright comes with higher compression which you dont want for a turbo. your better off goin with a supercharger if you dont plan on jacking up the boost and making major horsepower. you dont have to worry about backpressure with a supercharger you dont have to worry about anything if you just want some extra hp with out changing internals. the reason why companies put out turbo cars and they last just as good as the supercharged ones.talking about the mercedes. well thats easy. they are engineered that way. everything in those cars are meant to work together. they are built for turbos. nsxs are not. if you really want a turbo on your nsx it can be done and it can work well, but not if you dont want alot of hp from it. if you want a little extra quicker responsive, less to worry about go with a supercharger.

 

[jgtcnsx]

Leaner air/fuel ratios are in no way a result of higher compression – they are a result of programmable fuel injection and timing mapping. A lean (or rich) air/fuel ratio does very little to affect boost. Actually opposite of what you described, a little leaner air/fuel (hotter) will often help with spool up response on turbo based systems.

yes, you are right. compression ratio is the amount of air/fuel mixture that the engine compresses in the compression stroke.the ratio is the volume of the cylinder when the engine is a tdc(top-dead-center) over the volume of the cylinder when the engine is it bdc(bottom-dead-center) so, if the compression is higher then you have a leaner air/fuel mixture. right?the reson for running low compression allows more boost pressure without havin to retard the ignition timing to much. to much spark retard can result in to much heat on the combustion chamber,valves and the turbo and could also cause detonation.so alot of tuners run low compression. which to me i think engine detonation is a little higher on your chart than 5 percent.

 

[PaynNSX]

So you are taking the original $6500 kit and adding a $1200 AEM and getting 11's? Is that on a 3.0 or 3.2? Sounds impressive.

One thing I really like about Mark911's design is that he created a LOT more low-end Tq than stock or the BBSC.

I would love to get a ride in a properly tuned BBSC one day.

My car is a 97 3.2L backdated to OBDI and traditional throttle cable.

 

[PaynNSX]

backpressure causes what is called reversion. reversion is when the hot exhaust gases gt pumped back into the engine during the overlap period.reversion can cause the engines internal to get excessivly hot as cross flow of the cold intake charge during overlap is one of the ways an engine cools itslef internally. hot internal parts can trigger uncontrolled combustion and engine-destroying detonation.

So then why do we see the reversion effect with N/A 4 cylinder motors with large primary open headers (no cats, no exhaust) and very little inherent system backpressure to speak of? The reason is that reversion is an acoustic event related to so many other variables besides backpressure – displacement, valve and spring design, cam timing, cam design (overlap can play a very large roll), etc. Your “hot internal parts can trigger uncontrolled combustion and engine-destroying detonation” sentence applies towards supercharged engines as well.

you dont have to worry about backpressure with a supercharger you dont have to worry about anything if you just want some extra hp with out changing internals.

Either boost solution in moderation can be done successfully without changing internals. We have been boosting factory high compression (10.6:1 and higher) Honda motors for years with both supercharger and turbo based system with 100% equal reliability. The number one reliability variable in the equation is EFI management! The number two is owner greed. Both system types can have identical longevity.

so, if the compression is higher then you have a leaner air/fuel mixture. right?

Again, compression has nothing to do with air/fuel here. Programmable electronic fuel and timing mapping affects the air/fuel mixture.

which to me i think engine detonation is a little higher on your chart than 5 percent.

I never said detonation was lower than 5 percent. System backpressure was - I would say detonation ranks quite high on the concerns list.

 

[jgtcnsx]

yes reversion is related to those to. what i am saying is thats the biggest effect with small street turbos is the backpressure creating that. superchargers can have revesion but not as much as a turbo would. the turbines on the small turbos spool up faster then a bigger turbo from the exhaust pulses which is why they cause so much backpressure. superchargers dont.yes i am aware that they can both work well. like i have stated above.IMO running a small street turbo charger is not worth the problems to worry about instead of running a supercharger. turbos are harder to tune because the rely on exhaust pressure. were superchargers get a few ignition and fuel upgrades an normally require no engine tunning.also, When a a turbo is shut off oil inside the turbo's bearings can be baked by stored engine heat. This, combined with the turbo's extremely high rpms (up to 150,000rpm) can cause problems with the turbo's internal bearings and can shorten the life of the turbocharger. maybe not to you, but back pressure is a big issue and nsxs are big dollars to repair if something does go wrong.i would rather not have to worry about all of that for the same gain you can get from a supercharger(if you run a small turbo)

sorry mark, for blowing your thread up like this. it is my fault and i apoligize :redface:

 

[Factor X Motorsports]

It was a pleasure seeing you again this weekend. Good luck on the project!

 

[Mark911]

Just a quick update on the prototype ICed SC. Took my car out for the Dali Track Day at Spring Mountain race track in Nevada. The system performed flawlessly the whole day. I wish can say the same for my driving! (maybe I can blame my off track excursions on the extra 150hp)? Did lots of data logging and all the major parameters looked good. My intake air temps used to average around 180 F and peak at 250F or so (on a typical day, 75F ambient). On track day it was around 60F in the early afternoon and my air temps averaged only 90F and peaked after 20 minutes of laps at 120F. You can see the peak temps going very slowly from about 100F to 120F during the track session. I’d expect temps of 150F or so during the summer. That’s a nice 100F + degree reduction! What’s also nice is that the air temp doesn’t swing wildly back and forth some 70F as you get on and off the throttle like it did. The air to water IC acts like a big thermal stabilizer. This makes part throttle tuning more predictable. I did run into some issues with the stock knock sensors and AEM registering false knock signals and pulling back timing and adding fuel. This is an issue I had with the GM system as well. Looking at my data logs it’s obvious that something strange is happening as the ECU is showing knock almost randomly from part throttle low load to high load WFO. EGTs look fine, AFR looks good (even rich), and the plugs look fine. I even used a diagnostic microphone mounted to a bolt on the block to actually listen for knock while I was driving. None. After some discussion with Mike from Factor-X (thanks Mike) we concluded that it’s probably some weird harmonics between the blower and other engine components going in and out of phase. I’ll need to talk to AEM about a way to filter the signal so it only shows real knock.
Performance wise it was no comparison between the last time I was on the track. Although I don’t have track mapping capability I do log vehicle speed. I can say for sure that my top speed down the main straight was almost 20mph higher with the SCer. Lap times were lower also, but that’s kinda indirect evidence. My one spin was due to throttle on induced oversteer, a problem I never experienced (or at least never so easily) prior. So I’ll be making adjustments to my driving style. In addition, the CG is now a bit higher due to the SCer & IC location and I could feel it just a bit on corner entry. But at least the vital components are out of harms way! I hate to think of what would have happened to a “under the trunk” mounted oil cooler, intercooler or turbo after going off the track into a desert of small boulders and rocks like at Spring Mountain. Can you say “wasted”. Anyway, more info to follow. Mark