Whipple for the 8.1

tmf6902 · August 21, 2003

Ok, if you have a Whipple supercharger for your 8.1, how is it. Pro's/cons. Has it broken anything, did you have to make any other mods to accomodate it?

I am only looking at whipple because it runs pretty quite and my dad had one on his suburban, besides running to lean it worked/works/working great.

Do you have an intercooler? Is it nessecery(I can't spell today). How much better did your engine perform, I know they say 50% increase but what did you really see.where'd ya buy it, I search on the net last night, and the best price I could find for the non-intercooled black version was 3700 and change, which isnt to bad.

anyway Thanks

TMF

greyghost03 · August 21, 2003

TByrne has a supercharger on his 8.1L Burb, but I'm not sure if it's a Whipple or not. I think he can answer alot of your questions!

You can PM or e-mail him!

Pancho · August 21, 2003

I heard a rumor today that Wipple may be pulling the supercharger for the 8.1/Alli due to ongoing problems. Supposedly, Kenne Belle is coming out with something w/i the next several months but w/o an intercooler. Any truth to this??

CMNTMXR81 · August 22, 2003

Tom's is a Whipple. I think if mammory serves me correct he was doing an extra 100+ at the rears with it. One of the guys on superchargersonline.com (Dennis) used to work for Whipple I believe and has quoted me around 700lbs-ft of torque with the intercooled unit.

The only thing holding me back is a little new car (another toy) coming from Austrailia.

Tjwong · August 27, 2003

I have a Whipple on my 02 Suburban which is also an 8.1 but with the 4L80E transmission The blower has been in the truck for about a year now and so far no problems at all. But thats because I fixed all the weird stuff that was wrong with the kit.

Whipple and Kenne Bell both offer blower kits for the 8.1L engine. Both kits are well made and installs will relative ease. At the time of my installation the Kenne Bell kit was still under development. Whipple released theres about 6 months before the Bell kit was released.

The kit as far as installation goes went well. The problems came after the installation, in terms of setting DTC codes from the PCM. Codes that caused the PCM to through it into LIMP MODE or what is more commonly referred to as REDUCED POWER MODE. The problems I kept having was that it would throw out DTC P0103 and P1514, MAF sensor high and throttle body performance codes. I called Whipple about it several times, they blammed it on headers and the high flow exhaust system, which was all BS. I went as far as reinstalling the OEM exhaust system and it never went away. And Whipple never fixed the problem! And come to find out I was not the only one out there!

First off let me explain what you get with a Whipple kit. You get of course the mechanical parts such as the blower and the necessary mounting brackets and hardware. Also you get a boost enrichment EFI system which consists of a piggy back controller (mini-efi controller) wire harness, a fuel pump voltage booster(same as a Kenne Bell boosta pump) and two 50lb/hr auxillary fuel injectors.

The piggy back controller is wired (I didn't like intruding into the GM harness) into the factory PCM which in turns intercepts the following signals: MAP, MAF, TPS, Coolant and Intake air charge temps and crank signals. Plus it was wires in such a way that the right and left O2 signals went in series with their controller and the GM PCM.

The way this thing works is that if there is any problems such as something that went hey wire in the GM PCM their little controller would disable boost but applying 12 volts to the boost bypass solenoid. That is a good idea but not really needed seeing how if there was a major problem with the system you are not going to run past reduced power mode anyway. Their little controller was just part of the problem.

The main problem was the DTC the PCM was setting due to the fact that it was now a supercharged engine. DTC P1514 is the tac (throttle actuator control) and MAF performance code. It sets because air flow exceeded what the PCM expected to see at X TPS and X RPM and X MAP. The PCM has a look up table the lets it know what airflow is to be measured at the various TPS vs MAP vs RPM scales. If airflow exceeds what is in that table DTC 1514 sets and you my friend are in REDUCED POWER MODE.

After several phone calls and arguments I realized Whipple wasn't going to fix this for me. So I made the decision to fix it myself, either with GM's help or without. Well even with my connections GM wasn't going to help me so I waited until LS1 Edit was released and purchased it. Once I got my hands on the PCM programming tools I was able to go in and adjust the tables to stop DTC 1514 from setting. That cured that one problem, onto the next problems......

As stated above Whipple gives you a small piggy back controller to control boost enrichment. The way it works is when it sees X MAF flow and X TPS position it assumes that you are in boost. Then it sends the GM PCM a fixed 450mV O2 signal because remember the O2 sensors are wired in series with their controller and the PCM. Their controller intercepts the O2 signals and sends the PCM a set 450mV so that the PCM thinks its at STOICH and will stop trying to correct for lean and rich conditions. Their controller now starts their fuel enrichment by sending fuel through the two 50lb/hr Multec injectors that are mounted on the intake manifold housing where the GM throttle body once resided.

This picture shows the Whipple intake body as it connects to the intake the injectors here have been removed.

This is not a terrible idea, but what makes it so bad is that GM designed that intake manifold to be a dry intake. And that means that there is nothing that flows in it but dry air. Fuel is introduced by the factory injectors that spray it directly into the intake runner of the cylinder head and impinges onot the hot intake valve. Now with fuel being introduced into a manifold that was designed as being dry you have a couple problems. One fuel the fuel tends to condense and pool therefore making for p**s poor distribution into the cylinders. I proved this by installing thermocouples on my header tubes. I got as much as nearly 300* of temperature differential between cylinders. While there is always going to be a variance it is not going to vary by that much. Not to mention the surging that was felt when at WOT or when accelerating hard and the blower going into boost mode.

My fix was to remove all of Whipples electronic and return full control to the factory PCM. Larger 8.1L marine fuel injectors were installed, and the PCM was programmed to reflect the larger injectors and it was remapped for boost enrichment. Torque managment was also tuned out as was the factory PE delay mode. I spent several hours tuning it in and I am now very satisfied with how she runs. Fuel milage is as good as it can be considering it is a 496 CID engine, and of course drivability is as good as stock with not a bit of surging as with the Whipple electronics installed. After all the tuning was done I was able to replace the blower pulley to give me two more pounds of boost as well.

I also rewired Whipples boost bypass as well and their Boosta pump was retained to provide a 150% increase in fuel flow when under boost. The device is turned on with a boost pressure switch that is set to close at 3 PSI. You can see the pressure switch in the picture below.

All in all I am happy with the system now, and have since fixed several Whipple installations around my area here in Portland Oregon. Kenne Bells system is also a screwcharger and he does not use a piggy back controller but rather the same idea that I have. The PCM programming is implented by a supplied hand held flash programmer. You also get a set of marine injectors to replace the stock injectors with. Whipples mechanical installation is good but having to relocate the alternator is another weak point. So far I have had to repair the Whipple alternator bracket once and had to replace broken alternator adjustment bolts twice. Kenne Bells system does not require you to relocate the alternator. Both systems takes between 8 and 10 hours to install.

tmf6902 · August 28, 2003

tjwong, thanks for the explanation, I have heard that people were having problems with their wipples....and I have looked closely at the KB SC, since i first posted this question. If I were leaning towards one or the other I guess I am leaning towards kenne bell. I know it doesn't have a intercooler, but neither does the whipple unless you buy it. I don't plan on trying to goto the strip with it, I just want it for some fun on the beach, and just to have. But I do like how KB doesn't splice into the computer, and I am glad you told me about the alternator, I was looking at pics of a whipple installation and I swore the alt was on the opposite side as mine, but I thought I was just seeing things....ehhh...I'm not gonna get this mod till next summer, when I have a garage and can do it my self, so I have some time to do more research. Thanks for not blowing sunshine up my a&&, and telling me the way it is with your experience, it's something to think about.

tmf

Tjwong · August 28, 2003

Personally if I had it to do all over again. I am not so sure I would spend the extra cash on the intercooler. It is water cooled as you may well know. If you look at the top picture upper left of the pic near the air piping against the firewall you will see the reservoir for the coolant system. Behind and below the passenger side fog light resides the water pump for the coolant system.

Mind you if you are in stop and go traffic, that intercooler soaks up a engine heat like a sponge. And soon the coolant is at or near that same underhood temperature, so the efficiency of the intercooler drops way off to near zero. On the highway it may perform OK at best. I would have thought a better intercooling system would have been a large air to air unit placed behind the grill somewhere would have been much more effective. For an additional $1500 I could have paid for my complete exhaust system and then some.

I need to place a couple of my thermocouples in the inlet and outlet of the intercooler to see exactly what its doing. I have been out of the country for a long time and thats why I haven't been lurking around the forum much. With a dial up connection in a third world country, surfing the web isn't much fun, boy am I glad to be home where I can drive my toys, enjoy the fresh air and not have to worry if there is a toilet seat on the toilet in the McDonalds or not!

Dihappy · August 28, 2003

TJ,

GREAT write up...err. REVIEW

Thanks!

8100HD · August 28, 2003

Awesome write up, has helped me make up my mind, I can now see through the tire smoke, and I see a KB SC in my future. I've been back and forth between Whipple and KB, but after a real world review like that I know where my green will be spent.

CMNTMXR81 · August 28, 2003

I've been back and forth between KB and Whipple. Problem is, I am not well versed on PCM tuning. So it would've been a bitch for me to work out those kinks in LS1Edit.

The KB DOESN'T use an intercooler right? Not only do I see the problem with heatsoak but it would make the engine all that more difficult to service without having to remove major S/C components.

Pancho · August 28, 2003

Per Kenne Bell, they do not have a intercooler and their supercharger for the 8.1/Allison is not out yet? As of last week, it was to be released soemtime w/i the next several months.

How difficult is the install of a supercharger? The manufacturers would have you believe it is pretty easy bolt-on operation. Many of you here seem to have extensive experience in this area and I get the impression that there is a lot more to it.

CMNTMXR81 · August 28, 2003

I thought I remembered reading the KB felt it unessecary to need an intercooler due to their compressor/impeller/vane design (or something along those lines)

For install, A couple hours at least. What's nice as TJ pointed out, with the KB you won't have to relocate anything on the belt drive like the alternator as is the case on the Whipple. Then there's all the intercooler plumbing and install to add time to the Whipple.

A lot has to due with comprehending the instructions and then working out any kinks that they don't spell out in the instructions for you and of course any improvising and/or fabricating one may have to do.

Tjwong · August 28, 2003

As for the intercooler removal, it is very easy. It takes about 8 minutes to loosen the hose clamps, remove the plastic air ducting and one stud that holds the IC to the intake, lift and lay over towards the passenger side. The IC just "lays" there on tip of the rear most pastic air duct, it is held in place by the air ducting and one 6mm stud. A decent design actually.

Once the air duct is removed and the IC out of the way, remove serpentine belt then the larger idler/adjuster pulley on the main blower bracket, disconnect the TB electrical connections and the blower bypass solednoid connector, then remove the two 12mm bolts that once held the alternator in place, rock the blower up and down a couple times, then lift straight up and out. This takes about 8 more minutes to do. All in all to get at valve cover gaskets or what ever on top of the engine should take no more than 15 minutes to remove the blower components.

In this area Whipple did very well engineering the mounting of the major components. Where he messed up was that alternator mount as it is weak, it needs to be reinforced somehow or a different bracket design. I reinforced it with some additional steel. But I haven't got it right yet, as the vibration tends to shear off the lower 12mm adjustment bolt after about 6 or 7 months or about 6k miles.

The Kenne Bell unit mounts totally on the passenger side with its own casted bracketry. It is very strong and stable. KB uses the same manufacturer (Opcon) as Whipple for his blowers, they are of the same screwcharger technology as well. KB's blower is just a different model than what Whipple uses and is of a smaller displacement. But because of where KB mounted his blower and having less elbows he has less pressure drop to get the pressurized air into the engine. Therefore the need for a larger displacement blower was not needed. From the discharge of the blower he comes over and dumps directly to the intake, basically two bends. Whipples design with the IC has 5 90* bends and not to mention the pressure drop across the IC itself. This is just speculation on my part from my engineering background.

Another good point about the KB system is that it comes with larger injectors and a hand held programmer similar to a Hyper-Crap power programmer to reflash the PCM with. Therefore negating the need for the end user to worry about any programming needs and the need to buy LS1 Edit (EXPENSIVE!!) to program the PCM on his own. It is a well engineered system, and the good thing is that if you ever have a problem or a question you can call KB and speak with the man himself! I have spoken to Jim Bell on many occasions, he knows his stuff and he is a nice guy as well.

Both are good systems, both produce good usable HP and Torque. I just think KB covered the bases better and has the tuning right without having to intrude upon the factory PCM wire harness or having to try to manipulate what the PCM signals. It is my beleif that the best way to control fueling is to use the PCM, that is what it's there for. The GM PCM is one of the best PCMs ever designed it is fully capable of doing the job as long as it is programmed to do so. And that is what KB has done. The only reason one would need to get into the PCM programming is if one adds a cam to the engine or wants every last bit of Hp out of his engine. There is a fine line where the balance of power and longevity lies. Cross that line and things start to break I have been there and done that, I learned the hard way....good thing I have friends with GM

CMNTMXR81 · August 28, 2003

Thanks TJ, you're really sending me towards the KB. I am a mechanical genious albeit not an engineer and can fabricate mounts, brakects, etc, but I'm only average when it comes to tuning and agree 110%, let the GM PCM do the work and with KB's system any tampering with me using LS1edit isn't an issue.

Dihappy · August 28, 2003

Response from WHIPPLE

Henry,
It's true, we had some problems in the past regarding "reduced power mode" because of GM computer cals gettting more complicated. We've had that cured for almost a year now. Before this time, headers and extra parts aggravated the issue but as of now, you can do headers and other parts with no problems. We've never refused to fix a problem. As for the manifold not being designed for being wet, thats true, but very few are. When fuel is mixed and compressed with gas, the fuel atomizes together with the air, this is a pre combustion process. The cylinders that get air are going to get fuel. They are by no means the numbers claimed by others.

We have never had any claims regarding the alternator bracket (we have a 1 year warranty, you would think if it's a problem, we would get some claims). The alternator takes approx. 2-6hp and has very little load with the 6 rib belt. Typically most failures are caused by improper installation.

Our boost bypass valve that releases boost works during shifting (to reduce strain on transmission) as well as when the computer fails or see's a problem. Simply disabling codes is not always the best soloution. We have been on the market far longer than Kenne Bell and have sold 10 times more systems. This system was introduced well over 1 year before Bell.

Thanks,

Dustin

Whipple Superchargers