Republican TL

Call me crazy, but I like torque steer. If you anticipate and muscle it, its pretty fun. I remember my father's '88 323 GT. He had put a few HKS mods into it and it was at 200 hp. Car only weighed in at 2300-2400 pounds. Sucker had torque steer like no tomorrow. But if you drove the thing, you'd be all smiles. That little box rocked.

Anyone remember the 323 GT and GTX btw?

cvajs

is Comptech the one actually engineering this kit, or has Comptech hired someone like Alpine to engineer the kit for Comptech ??

i ask because i like to know where/who actually makes the aftermarket stuff i install.

thanks for keeping us updated on the progress.

Nitrotiger

as soon as i see there is no problems im looking for at least 70whp i spoke to them the told me 50whp and thats not worth $4500k i hope there is more to gain or a turbo maybe in the future

Joe5.0

You cant expect crazy gains from a blower like this, especially since the CR was upped for th 3rd gen TL's. 50whp is nothing to sneeze at. More importantly you gain ~50wtq from 2k-5k rpm, which helps around the town driving that much more fun.

Automatic CL-S 5AT's run around high 13's with the standard kit + headers, and with the high boost pulley more than a couple have run close to mid 13's. For the $$$ its hard to beat, if you're looking for reliable (relatively speaking) hp.

Nate@Comptech

Comptech engineers every supercharger kit we sell in house.

ONAGER

waste gate? do you mean blow off valve? waste gates are normally found on turbos. The wastegate is a valve that allows the exhaust to bypass the turbine blades. The wastegate senses the boost pressure. If the pressure gets too high, it could be an indicator that the turbine is spinning too quickly, so the wastegate bypasses some of the exhaust around the turbine blades, allowing the blades to slow down. a waste gate is operated off boost, once the car hits the proper boost level, the wastegate opens and bypasses exaust pressure on the turbine. this is why turbos will hit their boost level and then remain there. even if rpm continues to increase... superchargers on the other hand will continue to produce more boost as rpms go up (until their efficiency point is met at which point it will start to drop). thats why turbo cars can be changed "on the fly" you can change the amount of boost it takes to open the waste gate, in turn changing the amt of boost the turbo will produce. on superchargers you have to change pullys to increase blower speed.

blow off valves work on the intake side and vent any boost over a certain threshold, whatever boost its set up for. especially important when you close the throttle, as the supercharger (or turbo) is still producing boost, yet the throttle is closed. this protects againts compressor stall (and damage). most roots style/ screw stye (which is what computechs is) bypass the boost right back into the intake so it feeds itself the already boosted air (which is why you dont hear the psssshhh with them when you close the throtte, and you will on turbos and centrifigual blowers) thats also why if you are coasting on the hwy/ staying a a constant speed the supercharger isnt really producing much boost, as small throttle openings/closed throttle, the air the supercharger is producing is being bypassed and forced right back thru the charger... the air "cycleing in the system will be used before any additional air is drawn thru the maf... hence it is a closed system (no air is being vented or dumped, and the computer knows exactly what is being used) thats why its the prefered method of oem manufactuters (ford, mb)


off throttle a supercharger is not producing boost it will have a vacumm affect (car idling) thats why supercharger gauges read both vaccum and boost. a super charger will however produce boost almost imeadiatly (especially roots or screw blowers) so on the hwy fuel economy would actually be almost dead even with a na car. now anytime you are in the throttle you will be using more gas as the car will be getting more air (engines are nothing more then an air pump, the more air you force in the more fuel needs to accompany it) now a gentle foot will notice little difference... a heavy foot my cry all the way to the gas pump.

Repecat

Onager.....Informative post. Points for you.

cvajs

nope, i meant waste gate. original question was how to control the s/c boost. a blow-off valve does not give you control like a waste gate does. the problem with waste gating a s/c is where to dump the waste. a turbo simply bypasses like you say and the waste keeps going out the exhaust tubing. not so easy to do on a s/c.

ONAGER

never really heard of putting a waste gate on a supercharger.... dont get me wrong im sure that it can be done but no major manufacturer that i know of makes a super charger with such a device... many use bypass valves but none that i know of can externally contol the boost. that is one of the major detracters of a SC as you have to change a pully to change boost. so seeing as vortech, kenne bell, magnacharger, eaton. have not come up with a way to change that i belive it would be very difficult to do a shade tree mechanic fix

cvajs

Nate,
how many do you sell in house? (sarcasm, it just reads funny)


can you tell us who does the following for the "Comptech" SC:

1) castings
2) machine work
3) assembly

Nate@Comptech

I understand. I meant they are designed and tested in house.


We handle two of those three items. We are a full machine shop and machine a variety of products here. We have 2 engine dyno cells and a chassis dyno so we do all the testing here. We assemble every kit in house. We build the prototypes but do not have full production casting capabilities. I hope this answers your question.

TLGen3

NOICE!

iamhomin

Adding 60hp will do wonders for the 3rd gen TL.

I like it, but doubt many will be sold.

wavshrdr

I think some of you are missing the point about a SC. You complain that it is only adding 50WHP but the stress it is putting on the motor is much more than that! Even on a small motor a SC can be sucking up 50-100hp! On my MB they estimated that the SC was sucking up 100HP at redline just due to the drag of the blower. So you may think you aren't stressing your motor because you are only adding 50WHP but in reality you are putting substantially more stress on the internals than the modest 50WHP you are gaining.

Another thing to factor in is the 3.2 TL motor has high compression. This makes detonation a REAL issue if you are running much boost (and even if you aren't). So you will always need to buy excellent fuel! I don't see any sort of intercooler so this makes it even more critical. Of course adding and intercooler would drive the cost up.

While I like a SC I think NOS makes more sense. For the $3k you save you can refill a lot of bottles and actually end up with less stress on the motor for the increase you see at the wheels. Much easier to set up. Get a big bottle and it will last a long time on a small motor like the TL. It also won't put the thermal loads on the motor like forced induction will. It is also easy to remove if you decide to sell the car AND I like the fact that I can plumb it into the intake in such a way no one would ever see it.

BIGFISH

So how much boost will it produce?

My dad has a crate 5.9ltr MOPAR with ProCharger and intercooler that puts out 23 pounds of boost with a custom 1" pulley, because of the Supercharger he had to lower the Compression Ratio from 11:1 to 7.5:1 and with max boost he is at 19.something:1 because of that he had to go to titanium gaskets in the upper engine.

With our engines already at 11:1 compression just adding a SC with just 2 psi of boost will increase or compression ratio to 12.30 :1. From what I have read anything over 11.5:1 needs an octane additive to 93octane or 104 octane fuel.

Am I even close?

wavshrdr

Problem with high CR is you can't run much boost but if you drop the CR, off boost performance sucks. Normally a higher CR helps with fuel mileage too. What you are looking at is static CR and not effective running CR. Once the effective CR gets above about 8:1 you can't easily run on pump gas.

Effective running CR takes into account all factors such as cams, boost, etc. Don't forget that altitude also plays a big factor too. An absolutely great website is here:

http://www.smokemup.com/auto_math/index.php

You could spend hours poking around hear and really starting to learn the physics behind vehicle performance data and see what you can expect your car to run after you mod it.

I wanted to add one thing too. A quick way to determine the effective static CR or a boosted motor is this way:

Effective CR(Boosted) = ((Boost Pressure / Atmospheric Pressure) + 1) x Mechanical CR. So if you run 5psi boost you will see at sea level and STP ((5/14.7)+1)x 11.0 (TL's listed static CR) = 14.74 Effective STATIC CR.

spyfish007

If you start talking dynamic compression in here you are going to go over most people's heads quickly. I'm not sure how many people really understand the difference of a motor running 5 psi on CR of 9:1 when compared to 11:1. Most people just know the 5 psi of boost. There are some "facts" in this thread that are borderline junk when talking about superchargers or turbochargers. Each one has their strengths and can fit an application. Things such as backpressure, dynamic compression, timing, all play a factor. If you have heard a blanket statement like superchargers spool faster than turbos or turbos make more power, just take it with a grain of salt because given different situations each one can be better than the other. Proper engineering is the key! Sorry to rant, I just dislike hearing "myths" and "urban legends".

BIGFISH

Thats a great site. That will help me out loads when I rebuild my 87 mustang GT. I have grown weary of the riced out cars with can mufflers in my area so im going to build a rice killer.

wavshrdr

Dynamic CR is really quite important to understand. If people don't understand it, they should at least try to. A boosted motor is not child's play. It is not as simple as a Lego kit. I can't tell you how many people I've seen through a turbo kit on their car and never get it to run right nor anywhere near it's potential. If some things go over people's heads then maybe they should educate themselves before diving into OR find a shop that totally understands it and can idiot proof it as much as possible.

By understanding these things I know what I can safely do with my car or not. For example with my WRX I can crank the boost way up in the mountains without much worry about issues because I KNOW and can calculate the absolute pressure the motor will see at altitude. I understand the effects of density altitude. If people want to play with forced induction they really should try and understand it. If you talk to babies like babies then you do them a disservice and they will never grow. We have a lot of intelligent people here and if the concepts are explained correctly they can understand the concepts, their practical applications and the significance. I believe it is better to educate the people than to try and talk down to them. Let them rise to the challenge rather than assume they can't do it. It puts more work on the people with the knowledge as they must help with the knowledge transfer.

My father even though he was a brilliant oral surgeon also paid his way through his undergrad education by working on cars and aircraft. He instilled in me his work ethic and his love of cars and aircraft. He also knew that knowledge is power and to help people learn is one of the greatest gifts you can give people. Sure maybe some of the concepts are more difficult to understand than maybe some people here can immediately grasp but lets help them to understand it. A well informed consumer base will force manufacturers to build better products so we all win!

spyfish007

While I agree with what you said, I believe that is very idealistic. I think certain concepts are taught better in person. I just think there are some things are going to get very technical. People who share the idea of knowledge is power usually seek out the information own their own ...

wavshrdr

Problem is while some people are self-motivated they don't sometimes know where to start or what to look for. I would rather empower people and help them with their critical thinking so they at least have some ideas of what questions to ask. If you don't know what questions to ask, how can you begin to learn?

I have done a lot of teaching in my lifetime even on a professional level as in most of my income was derived from teaching and it can be difficult when your classroom is not in front of you. My hope is that if people were tech savvy enough to buy a car like the TL, that they are probably more open to other technical concepts and have a better understanding than many others.

I realize of course that you don't have to understand technology to use it. However it does help you to use it more effectively if you do understand it. How can you determine what mods are going to benefit your car the most unless you have a basic understanding of how they work? In turbo or supercharging a car with an already high compression ratio is something people contemplating doing it should understand. A high CR motor is going to be less forgiving of mistakes. Too much ignition advance, bad fuel, low octane fuel or too much boost can quickly lead to broken rings, pistons with extra holes in them for breathing, etc.

If you are going to lay down $3-4k on a SC kit you better understand what you are getting into. I don't even want to get into reliability issues but lets just think about states of tune. The higher the state of tune the more "finicky" it can become. It becomes more sensitive to everything. Potential buyers need to understand that. As Acura increased the power of the 3.2 over time it is now starting from a higher state of tune so there is less gains in percentage increases available to us, each HP will cost more to get, car is more likely to experience drivability issues, etc. There is no such thing as a free lunch.

More I think about it the more I am leaning toward a NOS kit for the car at some point. Actually my choice would be a light pressure turbo with about a dual stage 10/25HP shot of nitrous on demand.

NOX 3.2

From the picture it looks like the SC will also replace the CAI if you have one, right ?

tlguy99

Yes it has to.

Pro Stock John

Nate, is the supercharger an Eaton unit that you use? And the belt, is it a separate belt or do you use a longer serpentine main belt? And is it 6 rib?

cvajs

snip...
oh yeah, now your talkin good stuff. this would be a sweeeet setup, my only "wants" would be:
1) new cam profiles to take full advantage
2) larger exhaust
3) intercooler

my only concerns are:
1) where do you put the turbo and how to pipe it

wavshrdr

Since it would be a LPT setup you wouldn't need much to help it breathe. If I had more time I'd seriously consider building one. Anyone have any figures on what the duty cycles are currently on the injectors at WOT? It could be sweet if there is enough room left on the stock fuel system that we could just run the injectors a little harder and keep the boost about 5psi.

Cams while nice would be more hassle and cost than they are worth at this point but in a full on turbo motor with high boost I'd swap them out and also lower the CR. An air to water intercooler might be an option. Once we are up there in gas flow the exhaust might help.

PoochaKannInc

I'm assuming LPT means Low Pressure Turbo?

wavshrdr

Yes. LPT = Low Pressure Turbo or Light Pressure Turbo.

ravingstylez

can you put a blow off valve on a s/c??? ive never heard one go off on a s/c car

wavshrdr

Blow off valves are typically used so that the TURBO won't lose boost (as much anyway) between shifts on a manual car. If you are talking about a wastegate s/c cars rarely have them.

cvajs

could swap out injectors for larger ones and re-map the whole thing.

wavshrdr

Swapping the injector could work assuming the stock fuel pump will keep up. It is the old weakest link issue.

spyfish007

Are you sure about that? I've owned a turbo car and I know why you use them. I also know the differences between the use on a auto & manual.

I totally agree with degrees of tune for reliablity. However companies like Comptech have a really excellent track record so I would expect their kits to be ironed out. I can name venders in the RX-7 world who have good reps and bad reps. You do your homework on the bad rep shops if they have a product your really really think you want.

With the Comptech SC kits, I think the low gains in HP are a reflection of keeping reliability high due to the fact that the motor is already in a high state of tune. You can examine BMW M3's and how little power they are getting out of a turbo kit on the current generation. It is the same scenario.

With a final note, I think getting NOS to jet for such a small amout would be interesting. I'd have to do the math to see what I really think. I think cams on this motor could add much more than people realize due to the high CR. I'd almost argue for that .. then again I would have examined the lift/duration profile of our cams compared to some other Honda motors.

wavshrdr

Typically a turbo AT car can be shifted at WOT and the car never loses boost. As soon as you take your foot off the throttle the turbo starts to slow down. It can greatly reduce turbo lag as well as the shock wave that can sometime hit the turbo. I am talking about a BOV and not a wastegate. By venting the excess pressure when the engine isn't under load during shift you reduce stress on the turbo and you also reduce boost lag between shifts.

As for reliability I am all for keeping reliabilit on my daily driver. I also don't abuse my vehicles. My race TDI has seen over 50,000 miles with more than double the stock output of the motor. Tranny is fine and I put in a hi-perf clutch when I got serious with the motor and it's been in there for 47,000+ miles along with the Quaife.

I used NOS on turbo cars for several reasons. In my twin turbo Mustang I used the nitrous to help spool up the turbos and then it shot off when they reached 5 psi. I also used it as a chemical intercooler to help reduce charge air temps on ultra high speed runs. Even a small shot of NOS can help a motor quite a bit. I had a dual stage NOS kit on the 'Stang that gave a bigger shot at first and then the Hobbs pressure switch kicked it off and then it could come back on again in a lower dose at higher RPMs or I could manually select it if I wanted. It worked quite well. It was even more effective that way when I was running one big turbo at first and lag was more of an issue but that was a really stealthy car.

spyfish007

Well your earlier comment suggested that a blow off valve wouldn't lose boost where in this thread you say it will vent the pressure and hence the purpose. A BOV will DUMP larges amount of air and really drop the pressure in the intake. So therefore you are deliberately losing boost and protecting the turbo (as you mention). That is just a difference in your two quotes. Maybe I am reading things wrong.

wavshrdr

My comment was with respect to losing boost between shifts in that there will be less turbo lag. It is matter more of how it is read than written. You are actually venting to atmosphere the pressure so the turbo can stay spooled up and so there is no time lost due to the inertia of spooling the turbo back up. So in a way it is both as by venting boost in effect you don't slow the turbo down so once the BOV is closed the turbo hasn't spooled down so it can actually produce meaningful boost more quickly and as I mentioned they are really most beneficial on manual tranny cars as a well designed auto car with a turbo can be shifted at full throttle and very little loss in boost between shifts.

ONAGER

true.... the reason BOV arent as noticable on automatics, is that your foot never comes off the pedal when you accelerate.... so the engine stays at wide open throttle. while at WOT the engine is still using all the air its being given, the transmission disconnects the power, makes the gear change, and then reconnects the engine to the drivetrain. in a manual car you have to get off the gas to shift (well technically you dont, but it real hard on the car) when you close the throttle to shift, all the air that the turbo is producing has nowhere to go (throttle is closed, remember?) so the pressure would build up, until you have what is known as compressor stall. basically the pressure in the intake gets so high, it tries to flow backwards thru the turbo (back out the filter). when this happens the turbo stops rotating (compressor stall) extremly bad for the turbo. has been known to bend blades, damage the spindles and just plain tear them up. the BOV dumps all the air (a large chunk of it) in the intake when you close the throttle (it has a preset limit of boost, once thats reached its opened, will be reached very quickly with a sudden throttle change). it essentially dumps all the boost. but since the turbine is still "freewheeling" once the bov is closed the car will start to produce boost almost immeadiatly but there is some lag (slow shifters will have less then someone who speed shifts).

this is most notable in big heavy trucks with automatics they just keep chugging with gear changes.... manuals will always have that short delay after they shift where the truck seems to be dying (turbo isnt back up to speed yet) its something you really cant work around as those trucks are almost impossable to shift fast.

have fun

civic4982

talk about boost all of a sudden brings out all the pseudo-engineers

wavshrdr

Hey I represent that remark! But I am not a pseudo-engineer. I am the real deal it just happens to be in Aeronautical Engineering.

As for turbos the best thing to remember is that turbos ONLY produce boost when they are under load. Also remember they are actually turbines that run at very high speeds. The smaller turbos operating at over 200,000 rpm so there is latency (lag) in accelerating them from idle speeds up to the point that actually start to produce boost. Just think about how long it can actually take to accelerat from 10,000 rpm to 100,000 rpm or higher. It doesn't happen immediately and the bigger the turbo the more inertia that must be overcome. The bigger the turbo the longer it takes to spool up.

If you properly size the turbo(s) to the application you can usually minimize lag while still providing the power you want to achieve. There is no such thing as a free lunch and as a wise man once said "Speed costs! How fast can you afford to go?"

wavshrdr

The other stuff Onager wrote is accurate. This quote illustrates my earlier point about automatics and turbos in that you don't need to let off during shifts so the AT turbo cars are almost always faster than the MT turbo cars in acceleration. You just keep the pedal mashed to the floor and let the turbo work its magic. One the Datsun/Nissan turbo Z's first came out the AT version even with a crappy tranny was almost a half second quicker in the 1/4 mile than the MT version. I had the manual which was substantially faster on a road race course but after I raced against the first 2 AT Turbo Z's I knew there was no point in racing them again from a standing start. They kicked my butt by such a big margin it wasn't funny. It took a lot of mods for my MT to finally beat a normal automatic in the 1/4 miles.

One big plus with a turbo AT car is it is very easy to get boost off the line. You can brake torque the engine to put a load on the turbo and you have boost immediately. For a street car this can be a huge advantage.

What I really like about turbos is how easy they are to tweak. It is a very simple matter to adjust boost from within the cockpit. Not so easy to do with a SC. One area where this is very sweet is lets suppose you have your car set up for sea level and it is tuned to the maximum safe reliable levels you want. Now you take a trip up to the mountains. Since the air is less dense you could safely assume that you can increase the boost to compensate and still make the same HP you did at lower altitudes while normally aspirated (NA) cars are wheezing like they have emphysema. Now this holds true IF your turbo will still operate in an efficient area of its compressor map and that you aren't overspeedind the turbo. Whenever I go up into the Rocky mountains I always take advantage of this as it makes passing cars very easy.