Posts by Dave@DDMWorks

  • Bullet Speed Quad Conversion

    You can get Atom 2's with the supercharged Ecotec for around $45K used. One of our first twincharged Atom's sold for around that price recently with around 400whp and we have another person we are helping to purchase one in that price range also. It would be a neat comparison between a 4-wheel Slingshot and an Atom, the Atom's are actually a little bit of a handful to drive fast and remember that they do not have ABS, traction control or any nannies at all. They are also heavily biased to the rear for weight and have less steering angle than the Slingshot, so if the back starts to come around in the Atom, it is something you have to stay ahead of.

  • CLUTCH MC LEAK?

    The master cylinder is the same as a Pontiac Solstice, we have swapped one in to verify on a Slingshot that we had an issue with. Just wondering if you have the aftermarket cap on your clutch reservoir? The Slingshot we had here that we had to replace the master cylinder on had the aftermarket cap and it was leaking because of a lack of seal under the aftermarket cap. This allowed the clutch fluid to run down the hose to the clutch master cylinder and caused the rubber mount on the clutch master cylinder to fail. When the rubber failed on the master cylinder, when you pressed the clutch pedal all the way to the floor, the clutch would not fully disengage and made it very hard to shift.


    Not sure if that is related to anything you have going on.
    Dave


  • Engine Oil Lubricant Discussion Thread

    Quote from Bigdog

    Does the valvoline racing oil comply with the Polaris recommendations for warranty purposes?

    The Valvoline VR1 oil has not been licensed as Dexos certified. Just a guess, but I would not think that Valvoline would be worried about getting a race oil licensed as Dexos compatible even if it meets or exceeds the standards since they have plenty of regular oils that have been licensed as Dexos compatible.


    The Valvoline VR1 oil is not something I would even recommend though for most Slingshots, this is something for forced induction Slingshots that are putting a lot more stress on the engine than a naturally aspirated engine.


    Here is the complete list of Dexos compatible oils though if you want to check to see if one is on there -


    dexos1™ Gen 2 Brands | GM dexos® Licensing Program

  • Hawk Brake Pads on sale...

    Quote from MiM

    Everything you said @Dave@DDMWorks makes no sense on my helicopter... You sure you know what you're talking about? 8|


    Not applicable to Bumper boats, unicycles or Helicopters, sorry I didn't put that disclaimer in there.

    Quote from kev

    Yes ! thanks Dave@DDMWorks, finally somebody with a lot more credibility then little ole me , confirms you can get rid of mushy brakes (most times) by bleeding that fourth port ! I once was trying to explain to somebody named blitzekr... over on the dark side, how we have been very successful in just doing a ten mph skid with the right front wheel off the pavement and in the gravel , (verses Noel,s high speed brake jamming fix) which will immediately activate your ABS , then bleeding that port , but he then reiterated with five bold lines of , YOU MUST ACTIVATE THE ABS WITH DIGITAL WRENCH , over and over again ! so I just left it at that and played dumb , but chuckled like hell when @Tripod replied to him , so lets be clear, Do I have to activate my ABS with digital wrench ?


    If you really want to make sure, go out and activate the ABS a couple times to get fluid to move through those circuits. However, most of the time the air that is in the dead 4th leg can be removed by bleeding the closed off nipple on top of the ABS module. I am not going to say that in every circumstance it will always work, since I am sure there is going to be some person(s) that it will not. That being said, bleeding that 4th dead leg is relatively easy to do, requires no special tools and in our experience has made a significant difference, so why not try it and see if it works? If it doesn't then go down the path of using a digital wrench, etc.

  • Engine Oil Lubricant Discussion Thread

    Our most recent recommendation based on what we have been seeing with the turbo and supercharged engines is Valvoline VR1 oil in 10w-30. The VR1 oil is technically one of their race oils, but it also has a higher zinc/phosporus content. We have been seeing some wear on the rod bearings coming out of engines that have been ran hard with turbos/superchargers and the higher zinc will help, along with the slightly higher viscosity of the 10w-30 compared to the 5w-30. It is readily available and about the same price as Mobil 1 which is what we have typically used in the past.


    More info on Valvolines site - VR1™ Racing Oil (VR1™) : Product Catalog - Valvoline®


    VR-1 Oil Specs -
    Valvoline VR1 10W30 Racing Oil (Silver Bottle)
    Total detergent/dispersant (anti-deposit buildup/anti-sludge) = 2787 ppm
    Total anti-wear = 3019 ppm


    Valvoline VR1 10W30 Racing Oil (Silver Bottle, lab tested 2011)
    This one does NOT have the API symbol, but its text says it exceeds API SM
    Silicon = 10 ppm (anti-foaming agent in new oil, but in used oil, certain gasket materials and dirt can also add to this number)
    Boron = <5 ppm (detergent/dispersant, anti-deposit buildup/anti-sludge)
    Magnesium = 73 ppm (detergent/dispersant, anti-deposit buildup/anti-sludge)
    Calcium = 2707 ppm (detergent/dispersant, anti-deposit buildup/anti-sludge)
    Barium = 3 ppm (detergent/dispersant, anti-deposit buildup/anti-sludge)
    Total detergent/dispersant (anti-deposit buildup/anti-sludge) = 2787 ppm
    Zinc = 1472 ppm (anti-wear)
    Phos = 1544 ppm (anti-wear)
    Moly = 3 ppm (anti-wear)
    Total anti-wear = 3019 ppm
    Potassium = 6 ppm (anti-freeze inhibitor)
    Sodium = 380 ppm (anti-freeze inhibitor)
    TBN = 7.6 (Total Base Number is an acid neutralizer to prevent corrosion. Most gasoline engine motor oils start with TBN around 8 or 9. And in use, this becomes depleted over time as mileage accumulates)
    Viscosity (cSt at 100*C) = 11.0 (cSt range for SAE 30 is 9.3 to 12.4) And cSt (centistokes) in general terms, represents an oil’s thickness.




    Mobil 1 Oil Specs -
    Mobil 1 5W30 API SN
    Total detergent/dispersant (anti-deposit buildup/anti-sludge) = 1489 ppm
    Total anti-wear = 1755 ppm


    Mobil 1 5W30 API SN (lab tested 2011)
    Silicon = 8 ppm (anti-foaming agent in new oil, but in used oil, certain gasket materials and dirt can also add to this number)
    Boron = 87 ppm (detergent/dispersant, anti-deposit buildup/anti-sludge)
    Magnesium = 603 ppm (detergent/dispersant, anti-deposit buildup/anti-sludge)
    Calcium = 799 ppm (detergent/dispersant, anti-deposit buildup/anti-sludge)
    Barium = 0 ppm (detergent/dispersant, anti-deposit buildup/anti-sludge)
    Total detergent/dispersant (anti-deposit buildup/anti-sludge) = 1489 ppm
    Zinc = 801 ppm (anti-wear)
    Phos = 842 ppm (anti-wear)
    Moly = 112 ppm (anti-wear)
    Total anti-wear = 1755 ppm
    Potassium = <5 ppm (anti-freeze inhibitor)
    Sodium = 6 ppm (anti-freeze inhibitor)
    TBN = 7.5 (Total Base Number is an acid neutralizer to prevent corrosion. Most gasoline engine motor oils start with TBN around 8 or 9. And in use, this becomes depleted over time as mileage accumulates)
    Viscosity (cSt at 100*C) = 11.5 (cSt range for SAE 30 is 9.3 to 12.4) And cSt (centistokes) in general terms, represents an oil’s thickness.

  • Hawk Brake Pads on sale...

    Quote from nipper51

    It's my understanding (I'm old school)) the ABS has to be open to allow for correct bleeding of that system. The pulsating (antilock) comes from that metering device and by only hooking up the on board computer, that opens and clears the way for a complete bleeding of air to flush thru.
    So much for the old bench bleeding.

    There are a couple circuits for fluid to travel inside the ABS module. The standard fluid path (while the ABS is not engaged) does not require anything to be energized for that path to be open, otherwise if there was an electrical failure you would lose your brake pressure, and that would be a bad thing. When the ABS is activated though, the ABS system does open up a pathway to an accumulator to release some pressure and then can also open up another pathway to the ABS pump which returns brake pressure back to the master cylinder. In order to get air out of that pathway, the ABS would need to be activated for fluid to travel that circuit. That being said though, that system returns pressure and fluid back to the master cylinder and the air should go back with any fluid and simply go into the reservoir since air is going to travel to the highest point in the system. The problem we typically have seen with the ABS module needing to be bled is that the empty 4th line that is capped off on the ABS module is the highest point on that dead leg, so even if the ABS module is activated, any air in that leg can not travel back down into the ABS module and return back to the reservoir. Also since any air in that 4th dead leg would be part of the normal brake pressure circuit, it will make the brakes feel "mushy" or soft, which is one of the complaints we often hear with the Slingshots.


    That is why bleeding the dead port on the ABS module without activating the ABS works in most cases since it is the high point on that 4th dead leg, although I am sure there are going to be exceptions.


    Hope that helps,
    Dave

  • Hawk Brake Pads on sale...

    Quote from Bigdog

    Explain the procedure for bleeding the ABS....do you bleed it after the 3 wheels and do you need to pump the brakes to bleed the ABS? Thanks

    When we bleed the brakes here, we start with the rear caliper first. Then we do the passenger side front and then the drivers front. Last is the ABS module itself, there is one rubber nipple on it, pop off the nipple and use a 10mm wrench to loosen the bleed, after bleeding that nipple, tighten the nipple back with the 10mm wrench and clean any extra brake fluid that may have dripped out off of any painted surface.

    Quote from Bigdog

    I can't ever remember a car mechanic talk about bleeding the ABS

    Since the Slingshot uses a ABS module from a car, but they only use 3 of the 4 ports is the reason that you have to bleed at the ABS module. In most cars all 4 ports would be used, so you can just bleed all the air out at the calipers.


    Hope that helps,
    Dave

  • Need advise, Some kind of engine noise that's not good

    After listening to the video again (sorry, when I first heard it over the weekend it was on @rabtech phone), another thing that you should check is the timing chain, timing chain guides and timing chain tensioner again. We have seen a decent amount of the timing chain tensioners go bad and also the timing chain guides in the front of the engine crack or break, although usually at higher mileage than you are reporting. Another thing I would pull and check is the VVT solenoids on the top of the engine (2 silver canisters sticking up on the front of the engine with electrical connectors on top). They come out pretty easily, just remove the single 10mm bolt and disconnect the electrical connector, twist and pull up and they will slide out of the engine. There are screens on those solenoids, look to see if you have any debris on those screens and clean the solenoids with some brake cleaner and re-install.


    Was the noise as bad with the Mobil 1 compared to the Rotella? Did you notice a definite increase associated with the timeframe that you changed oil also?


    What I hear in that video is sometimes what we will hear in Solstice/Sky 2.4L when the oil is left in for a long time and the VVT actuators can not work correctly. I have had people call and think that they blew up their engines because of that noise and then after cleaning the VVT solenoids and changing the oil the noise goes away. It is hard to diagnose anything long distance, but something to check for sure.


    Just some other things to check, keep us up to date on what you find.
    Hope that helps,
    Dave

  • Bugzilla's supercharged destroked 2.4L build


    That was a very early test of the cams, without any associated tuning to take advantage of the change in VE of the engine. We also were able to drop a pulley size on that dyno at the same time while still maintaining the same boost pressure as the larger pulley we ran before, which increased the VE of the supercharger in the lower RPM range, ahd had the result of increasing midrange torque. We had tried the smaller pulley's previously, but because of the increase in pressure delta on the supercharger, the net power did not increase like what we saw with the cams installed.


    As for the rev limiter on the engine and where to set it, that has more to do with the calculated torque at the wheels and how the engine is making torque. A simple Excel sheet with torque and gear ratios will show exactly where you should shift and what RPM is actually useful in each gear. Although there are times like autocross, where even though you may make more torque at the wheels in the next gear, saving the shift time means it is actually beneficial to hold the same gear out to a higher RPM.


    Attached is a sheet that we have done on other setups to show the torque at the wheels. All we do on these graphs is input the torque from a dyno of the vehicle at different engine RPM's (every 250RPM) and the gearing of the transmission and final drive. That will calculate the torque at the wheels and also plot it on the graph. Then you find the point at which they cross and that is your optimal shift point for each gear. Spinning the engine beyond that point means you are making less power at the wheels and you would accelerate quicker in the next gear.


    Hope that helps,
    Dave


  • How difficult to install?

    When we are installing them we put some blue painters tape along the front and sides of the surge tank also to help protect it from getting scratched during the installation. Like others have said, it is a tight fit to get it in there. Then once it is installed, peel the tape off.


    Hope that helps,
    Dave