Comptech High Boost vs. Normal Boost SC

[yoda888]

Hi folks, I've done some searching, but can't find a lot (or at least that I can understand) in regards to high boost vs. regular/normal boost SCs. So please bare with me and my questions.

-What's the difference between high boost and regular boost? (I mean I know more lbs in the boost, but is it just a pulley? a different blower? etc)
-Can you take a high boost setup and make it into a regular boost setup by changing a couple of simple parts?
-Where can I find more information in regards to this? (The CT site is very lacking in details! Heck it doesn't even tell you what comes with the regular kits!)

Any other info would be appreciated.

Thx

 

[BATMANs]

I have the SOS SC in high boost, which is 10~psi. Same blower. I think the low boost is 5-6~ psi.

Considering how much these SC costs, u really feel like $$$ well spent on the high boost setup.

I think these are the upgrades:

1. fuel pump
2. pulley
3. injectors

 

[pgilliam1]

I have been told that the CT unit spools faster and holds more boost at lower rpm's and idle, which means faster accelleration. A dyno sheet should show this. This is second hand info - so it could be worthless, but maybe it will steer you to look at some dyno results.

 

[RYU]

Hi folks, I've done some searching, but can't find a lot (or at least that I can understand) in regards to high boost vs. regular/normal boost SCs. So please bare with me and my questions.

-What's the difference between high boost and regular boost? (I mean I know more lbs in the boost, but is it just a pulley? a different blower? etc)
-Can you take a high boost setup and make it into a regular boost setup by changing a couple of simple parts?
-Where can I find more information in regards to this? (The CT site is very lacking in details! Heck it doesn't even tell you what comes with the regular kits!)

Any other info would be appreciated.

Thx

I'll try to summarize for you but you really need to do a search. Admittedly the information is sort of all over the place.

First of all there are two types of Comptech Superchargers. Older ones are the Whipple units and the newer ones are Autorotor units. Old ones are 1.6L new ones are 1.7L in displacement. The max boost is 6.5lbs (at least that's what it is on my newer 1.7L Autorotor) on the stock "low boost" pulley. This was/is sold as a standard kit by CT engineering who was once called Comptech (to make a long story short). I've read the older whipple units had 5-7lbs of low boost but the variance may be due to altitude variations.

High boost setups are a bit more vague. SOS sells a "high boost" upgrade and so did Comptech at one point in time. There was no real canned, out-of-the-box high boost setup that i've found but in my research. Comptech once sold a recalibrated RRFPR with a set of higher capacity Honda injectors in additional the the smaller pulleys.

The Whipple and Autorotor take different diameter pulleys to achieve the same amount of boost. You cannot put the same high boost pulley on the Autotorotor made for the Whipple and expect the same boost levels.. Actually, i'm not even sure they will bolt on interchangeably.

The SOS 2.1L Kenne Bell unit is a different unit and was never sold by CT or Comptech but they use some of the original Comptech parts.

 

[Blacknot]

I have the old CT whipple which I got already on the car. It had the low boost 6lbs and made 365whp. I upgraded to an AEM Fic, 550 injectors, walboro 255 fuel pump, meth injection and custom 10lb pulley which was VERY expensive. So I would suggest getting the SOS kit since it comes with all you need. I'm actually going to the dyno tomorrow to get a final tune on 10lbs. I'm curious to see the power I make compared to the SOS kit since my blower is smaller.

 

[yoda888]

So it seems based on the responses thus far, the "high boost" kit is somewhat of a mythical creature in that it was made only for a short time by CT and little information is out there on it.

Here's the reason I'm asking really. I'm looking at a NSX that has a CTSC high boost setup. This is a nice setup and it was done right. But, it might be "too much" for me, so I was wondering what it would take to either:
a. remove the CTSC altogether
b. "downgrade" to the standard CTSC kit

There are a couple of reasons for this. One is reliability (not that it would be a DD). I'm at the age where I just don't want to deal with "stuff" anymore (at least not as much). I think the second and more important is that my understanding is it won't pass smog here in CA. I don't want to have to deal with this every 2-years.

Or maybe i'm just over thinking this! :tongue:

 

[Aaron94T]

I have been told that the CT unit spools faster and holds more boost at lower rpm's and idle, which means faster accelleration. A dyno sheet should show this. This is second hand info - so it could be worthless, but maybe it will steer you to look at some dyno results.

What? Boost at idle, positive displacement charges spooling? A dyno chart will not help him unless he wants to confirm that 8psi makes more hp than 6psi.

Anywho, I wonder if I can get away with a fuel pump and pulley for my 1.6. From what I have read a F/IC is required as well. I was assuming the stock CT injectors would be enough for 380ish wheel.

 

[Hrant]

For reference, on my 98-T 3.2L CTSC with the 1.7L Autorotor regular pulley Dynoed at 7 boost 362 rwhp @7800 RPM and 254 lbft torque @5800 RPM. I have seen the SPA boost gauge show 7.5 and occasionally even 8 all with the original setup - perhaps some variance between Dyno machine vs SPA gauge.

YMMV

EDit: I should have also added that the numbers can be "made" to look what you want using some trade trick in Dyno. The key is the net gain from one's baseline. My gain was 108 rwhp and 48 lbft torque; with CTSC header and exhaust.

 

[Blacknot]

What? Boost at idle, positive displacement charges spooling? A dyno chart will not help him unless he wants to confirm that 8psi makes more hp than 6psi.

Anywho, I wonder if I can get away with a fuel pump and pulley for my 1.6. From what I have read a F/IC is required as well. I was assuming the stock CT injectors would be enough for 380ish wheel.

Here is the problem. I had my car dynoed and the a/f was in the 13's on 6lbs and this is very common. The comptech kit uses stock injectors which are totally maxed out and a fmu which is very old technology. I upgraded the fuel pump which as a band aid because then the car ran rich on the bottom end. With the cost of an Nsx motor you are crazy not to get proper fuel management such as a stand alone or Fic. That's why I just spent all that money upgrading mine. A/f in the 13's is going to blow the motor eventually

 

[RYU]

Hrant, in your experience what's been the average "lowboost" levels? Does anyone know what the original published boost levels were suppose to be? I'm using a Spearco gauge temporarily and it's showing 6.5-7lbs on the low boost Autorotor. I'll be getting a digital map sensor soon to verify a more accurate #. It would be nice to know if i'm bleeding boost somewhere.

Yoda888, I don't think the high boost kit is mythical per say. There is just no dominant high boost kit out there i've seen. Furthermore, it's pretty common knowledge that a CTSC putting out 9-10lbs would be considered high boost via a smaller pulley but how the fuel side is being addressed is sort of all over the place. Most "high boost" kits i've seen have opted for a stand alone ECU or FIC for better granular control of fuel and timing. When you say the car you're looking at is done right, how do you know it's done right? What fueling provisions have they used?

 

[Blacknot]

Hrant, in your experience what's been the average "lowboost" levels? Does anyone know what the original published boost levels were suppose to be? I'm using a Spearco gauge temporarily and it's showing 6.5-7lbs on the low boost Autorotor. I'll be getting a digital map sensor soon to verify a more accurate #. It would be nice to know if i'm bleeding boost somewhere.

Yoda888, I don't think the high boost kit is mythical per say. There is just no dominant high boost kit out there i've seen. Furthermore, it's pretty common knowledge that a CTSC putting out 9-10lbs would be considered high boost via a smaller pulley but how the fuel side is being addressed is sort of all over the place. Most "high boost" kits i've seen have opted for a stand alone ECU or FIC for better granular control of fuel and timing. When you say the car you're looking at is done right, how do you know it's done right? What fueling provisions have they used?

I have been told by my shop that I have used 10+ years that has a lot of experience with Hondas and superchargers that the Honda motors breath so well up top that with superchargers you tend to lose about. .5-1lbs of boost up top since the charger can't keep up with how much the motor is flowing up top. It is possible since Hondas heads flow better than any other motor. Maybe someone can chime in with some knowledge to add to this.

 

[Hrant]

I believe my readings are correct. Shad drove it yesterday as I was a bit concerned with low mpg (fixing vaccum hose 4 may solve this) and he commented that the car was strong showing 7.5 boost on the SPA gauge. I believe 7 was the "expected" norm - Autorotor was rated slightly higher in boost than the Whipple. Your reading of 6.5-7.0 could be a gauge issue.

Yes regarding fuel management and injector change for using "high" boost (aka smaller pulley) with the Autorotor ....... and once you go that route more variables to worry.

 

[ozone]

EDit: I should have also added that the numbers can be "made" to look what you want using some trade trick in Dyno. The key is the net gain from one's baseline. My gain was 108 rwhp and 48 lbft torque; with CTSC header and exhaust.

Informative thread. CTSC gain of over 100whp? That's solid--they advertise 60-70 and I realize they are being conservative, but that's awesome. I've been torn between CTSC v SOS SC, a decision I have to make soon. Like the OP said, I don't want to be worried about "stuff" so that draws me to the near OEM-like CTSC. But the gains from SOS are supposed to be so much more and people say its very good. But I don't want to worry about engine management, etc. But if CTSC is a solid 100whp then may not be worth the additional headache involved with the extra ponies--totally torn between the two.

 

[Hrant]

Yes 107.7 rwhp to be exact :wink:

The 60-70 rwhp estimates do not include header/exhaust and your tuner can still pull a few more ponies.

Given that you are in NY, you may not have the same CARB issues that we have here in CA. So perhaps your options are more than we who want to be street legal with no headaches. The CTCS - either the Whipple or Autorotor is pretty much bullet proof. Once you start tinkering with high boost, intercooler may become necessary if you track the car ....

But frankly for street driving, what does an additional 50 rwhp do for you? Bragging rights? Just a bit faster 0-60 mph? Or a bigger smile on your face until you are pulled for reckless driving :tongue:

 

[NetViper]

So it seems based on the responses thus far, the "high boost" kit is somewhat of a mythical creature in that it was made only for a short time by CT and little information is out there on it.

Here's the reason I'm asking really. I'm looking at a NSX that has a CTSC high boost setup. This is a nice setup and it was done right. But, it might be "too much" for me, so I was wondering what it would take to either:
a. remove the CTSC altogether
b. "downgrade" to the standard CTSC kit

There are a couple of reasons for this. One is reliability (not that it would be a DD). I'm at the age where I just don't want to deal with "stuff" anymore (at least not as much). I think the second and more important is that my understanding is it won't pass smog here in CA. I don't want to have to deal with this every 2-years.

Or maybe i'm just over thinking this! :tongue:

I think if I were in your situation, I would go with aem fic and get it tuned properly and call it a day.

 

[Ric]

Netviper, did you previously have a regular ctsc nsx and the engine blew up? I currently have a whipple ctsc with aem standalone but I imagine one day I will revert back to the regular ctsc and not have to worry about swapping stuffs out for smog test in California every 2 years. I don't want to go NA because I know for sure I will miss the power.

 

[NetViper]

Netviper, did you previously have a regular ctsc nsx and the engine blew up? I currently have a whipple ctsc with aem standalone but I imagine one day I will revert back to the regular ctsc and not have to worry about swapping stuffs out for smog test in California every 2 years. I don't want to go NA because I know for sure I will miss the power.

No, I had a bbsc and a bad motor to start with.

I am happy with the ctsc setup. It makes good power, the a/f looks solid and it has proven to be very reliable.

Would I like more power? Sure, but I don't want to spend another 2-3k for 30hp and more stress on the motor.

 

[jmp]

The term "high boost" may cause some confusion The CTSC auto rotor pulley that came with the kit was sized to target 6 lbs of boost. I believe there is more than one smaller pulley, which is the same thing as saying there is more than one "high" boost pulley. I have a pulley that targets 8 lbs of boost (I don't recall the size of th pulley) after having started with the 6 pounder. I have never seen more than about 7.5 lbs with the "8 lb. pulley" on a dyno. i have heard some folks (including in this thread i believe) that have smaller pulleys for 10 lbs. My 3 liter with cat bypasses, aem standalone, 550 injectors, 255 walbro, etc and snow perf meth injection dynos at 389 whp and is reliable and a blast to drive on the street. i have put close to 20k miles on it without a hitch. Just make sure to have a good local tuner. i highly recommend this setup or those that have been developed since that are very similar.

 

[type-j]

So how much more stress does the standard ctsc put on the motor? would it fail faster then the same motor being NA even though its just being street driven?
how often would you say the motor needs to be tuned with the standard ctsc? I think there's about 15k miles on my ctsc and everything seems to be running well. can I expect the reliability to last? ( I do moderate with a little "spirited" driving almost daily for 5 months out of the year)

 

[comtec]

I purchased a whipple high boost kit but would like to install it as low boost. I know i can change the pulley and use my oem injectors instead of the ones in the kit. What about the fuel system, will anything need to be changed?

Thanks
Mike

 

[RYU]

I purchased a whipple high boost kit but would like to install it as low boost. I know i can change the pulley and use my oem injectors instead of the ones in the kit. What about the fuel system, will anything need to be changed?

Thanks
Mike

What is included in your CTSC kit's fuel system now? Need a detailed inventory of your existing parts...

Best case, you likely have everything you need and will simply have to readjust your RRFPR to achieve the best possible fuel trims.

 

[comtec]

I just bought it last week and haven't received it yet but this is what i know of - Signal Modifier, Fuel Enrichment Modifier, Fuel Pressure Regulator (x2), Updated Fuel Line.

Thank you
Mike

 

[RYU]

You'll need an AFR gauge and a fuel pressure gauge and you need to start tweaking the RRFPR (rising rate fuel pressure regulator).

Or you can take it to a tuner.

 

[comtec]

You'll need an AFR gauge and a fuel pressure gauge and you need to start tweaking the RRFPR (rising rate fuel pressure regulator).

Or you can take it to a tuner.

Thanks RYU, sounds like i have everything i need. One of the regulators is new so maybe (fingers crossed), it is set correct for the low boost.


Mike

 

[RYU]

Thanks RYU, sounds like i have everything i need. One of the regulators is new so maybe (fingers crossed), it is set correct for the low boost.


Mike

Unless your new RRFRP is from CT themselves and properly pre-calibrated to low boost (or at least high boost) be careful on your first WOT pull. If it's an out-of-the-box unit from Vortech it could have the wrong baseline setting and worse.. wrong spring. You'll at least be able to set the base fuel pressure at idle.

If you're going thru all this trouble it's worth looking into a piggyback or standalone.