Posts by Dave@DDMWorks


    Have you installed these type of set-ups Slings with one of your built engines? Would it be beneficial for the set-up we have been discussing?



    We have installed a lot of the water/meth setups now on Slingshots with and without our engines. We could add something like that on your build, you might talk with MACAWS, he had a hahn kit and our tune and injectors and was making really good power, low 400's on just pump gas.

    15psi of boost pressure at the intake manifold is not always going to be the limit you can run on 93 octane, the knock threshold is going to be dependent on a lot of factors, boost pressure is not the sole factor. There are plenty of Ecotec's running around on higher pressures than that on 93 octane out there.

    There are a couple other factors right off that I can think of that contributes to pre-ignition also -

    - The air/fuel ratio

    - How homogenous the mixture is in the cylinder (there can be pockets of different air/fuel mixtures within the cylinder)

    - Carbon deposits on exhaust valves

    - Too far advanced timing

    - Spark plugs in the wrong heat range

    I am sure there are some others, that is just off the top of my head.

    Water/Meth is one of our favorites to run here on high boost setups. It does a couple good things compared to E85. With the water/meth spraying you keep the engine overall much cleaner. Also, if you run out of water/meth, you can still just keep driving (staying in low boost where water/meth is not needed) on 93 octane. If you are traveling you can typically find higher octane gas, but E85 is sometimes hard to find when traveling. For all out race cars E85+ can be fun, but for anyone that drives their vehicle on a daily basis, 93 octane with water/meth has been more preferred by our customers.

    Hope that helps,


    well, today they had a very limited launch window - launching a rocket off of a spinning ball to meetup with an object in space that is orbiting around that spinning ball at 4.76 miles per second and timing it all right so that the rocket has the fuel to put the capsule it the correct orbit so that this can all be done is complicated and requires precise timing - - add to this that in the case of these maned launches they need good weather out over the ocean all the way up over Canadian waters just in case they need to abort the launch and bring the astronauts back down.

    if it were easy this would not be the first time ever that this was being done by a private company - seriously in all of history only the U.S. Russia/USSR and China have ever put a human into space

    Hoping for good weather on Saturday a couple of us might head down that way to see the launch :thumbsup:

    Wow, that is really sad to hear, really have no words, even though he started out as a customer, he really became a good friend that hung out at our tent at the events, definitely going to miss having him around with his quick wit and humor. Definitely thinking of his family, I know all of us here will have them in our thoughts and prayers. You will be missed Rob!

    Awesome, thanks for the clutch order, we really appreciate it!

    The shift adapter will bolt to the top of the shifter coming out of the transmission for sure, typically I would not recommend it since you can not put a shift boot around it like the other shift adapters we have for the Slingshot, however with your setup, I don't think that will be an issue ;)

    We could do something like that shift knob, let me see what I can model up :thumbsup:

    How Many of you installed Head Studs on a ZZP or DDM Stage 1 Turbo install?

    Early on, back in the days when Alpha was still around, Henry at Alpha made a big deal about installing head studs in all of the turbo engines that they installed their turbo kits on. Towards the end, Alpha started to have a lot of engine failures with their turbo kit caused by several factors, head studs not being one of the issues. They were destroying a lot of pistons with their kit installed, and the thought was they were lifting the cylinder head and coolant was getting into the cylinders and destroying the engine, hence the ARP headstuds were installed to help prevent this from happening. As I mentioned earlier though, that was not the issue causing the engine failures. Henry at Alpha claimed he saw loose stock head bolts and that was the reason that they made a big deal about swapping in the ARP headstuds. So a lot of those kits you will find have the ARP headstuds installed.

    That being said, I would say a significant portion of all the supercharger and turbo kits we have been selling/installing for the Slingshot since 2015 go on completely stock engines with no internal upgrades. We do not actively recommend the ARP studs to customers when selling either or supercharger or turbo kits, as there is some risk to installing the studs and for the most part the stock head bolts have proven to work at the power levels we recommend running our kits at. The engine failures we have seen out there with turbo kits are typically from heat related issues at the piston, which causes piston failure or engine knock due to tuning/mechanical issues. There is one kit that does have a tendency to destroy rods, none of these failures are not caused by a lack of ARP head studs installed in the engine.

    We have had a stock Slingshot 2.4L engine with 2 head bolts loose from the factory show up here. I couldn't believe it, but did shoot video of it just to document it, that is pretty rare though. Even with those 2 loose bolts, the engine operated fine with a Stage 1 turbo on it. We did replace all of the head bolts with ARP head studs in that case.

    So, if you want to install the ARP headstuds, it is going to be nice insurance and a good idea if you really want to make things as safe as possible, but in general we have not seen a big need for it with our supercharger or turbo kits.

    Hope that helps,


    If you are still planning on maxing out that Stage 3 with the 4 wheel, I am definitely going to recommend the track clutch on our setup.

    I have the "performance" clutch. It's not a problem for every day use. The wife complains about it being stiff and causing her leg to cramp up but it's never been an issue for me. Dave@DDMWorks can tell you which one I have. Got close to 20K miles on it now.

    Ghost - You do have our most aggressive clutch, as the street disc was not an option at that time. The 6 puck version you have is a little bit aggressive, but will hold the power you have no problem.

    I appreciate the quick responses. I'm not sure I even have my cat any longer. I do know that the exhaust made a huge difference. We are in AZ, and my wife's feet melted in the summer before we got rid of the cat. And I'm a big guy (320 lbs with a paunch, but I was a 300 lb linebacker so I can't lose too much). Fully loaded with wife and gear I'm over the supposed cargo capacity. I'm not worried about that, but there was a huge difference with the header/exhaust. Off the line, and pulling hills in a higher gear than I could before (we live at a mile above sea level). I don't think I can give that up.....

    Do you have the 1320 header and 1320 rear exit exhaust?

    If so, you do not have a catalytic converter any longer for sure.

    There have been some people that have had luck with the rear deck spoiler decreasing fumes in the cabin also, not sure if you have seen those. Also, Welter used to have some small flaps that they ran under the Slingshot that created some turbulence and help eliminate fumes also you could check into.

    All of the rear exhaust systems do not go below the Slings frame

    The Welter 2.5" is tucked up above the frame rails all the way back. The Thermal research rear exit though does sit below the frame rails in the back -

    Not sure if it is just the prototype, but the pictures of ZZP's rear exhaust also show it lower than the frame, Kyle D can answer that though for sure -

    The 1320 rear exit exhaust also sits slightly below the frame -

    Hope that helps,


    Install looks great, really hope you get out and enjoy it! Thanks for hanging in there with the weird UPS delivery issue! If there is anything else we can answer or help you with, just let us know!


    Got everything today, fired it up and had a coolant line leaking. Took it off and the flare was cracked. DDM overnighting me another one so hopefully I can fire it up tomorrow before the blizzard this weekend lol. Anyways installed my AEM failsafe tonight. Configuring the gauge what is the ideal AFR for boosted slingshot engines 12-15 ? Not looking for the perfect number just range from idle to load.

    Thanks guys

    Post some pics maybe a video when I get it all together. ..... maybe tomorrow.

    On that failsafe gauge, we usually set 12.5:1 AFR and 5psi for the start monitoring pressure on that gauge.

    I hope I get to meet you next time I am in Texas, looks like you are enjoying the heck out of that thing and having a lot of fun :)

    Hey gang, long time no see! I’ve been reading up on posts, but wanted to share some mods I’ve been doing and weight in on the coolant. I just converted all my lines over and my tank to the ones sold by DDM Works. The tank had split right on the seam. Luckily my amazing wife had ordered all this stuff for me and I just hadn’t had any free time to put it on. I used this opportunity to flush all the dex cool out of the system and fill it with Peak Final Charge. I will say imho there is a noticeable difference on how hot the sling runs. This coolant is usually used on over road trucks but is used for any severe engine condition both gas and diesel. It’s guaranteed 8 years or 1,000,000 miles. I had considered the waterless coolant but thought if I ever had a roadside emergency this would be easier to get my hands on. Our local farm and fleet sells it for $14 per gallon. Overall I am very pleased with the result. I changed all the fluids to Amsoil products and added the ZZP rear pinion brace. A must have for any sling!!!!

    For my next addition I would like to add a Fab Factory intake manifold but since they’re no longer being made... I’m hoping to pick one up used!

    Any who, I hope to change the sway bar, links and mounts yet this week also should the weather hold out :00008698:

    The engine bay is coming along nicely, looking good!

    As for the intake manifold, if you do add that you will have to make a custom intake as the Alpha one you have now will not bolt up to it, just want to make sure you knew that before swapping it out with the stock manifold.

    Also, as Kyle mentioned, we have dynoed a couple Slingshots and on boosted applications atleast, the 2 aftermarket intake manifolds (HAHN and Fab Factory) do not make as much power as the stock intake manifold.

    Hope that helps,


    The EVAP solenoid does not have a one way check valve. If you switch over to the Haltech you do not need the EVAP solenoid and can remove it from the back of the engine and just cap the nipple on the intake manifold, or use it for a boost reference.

    part 1, 5 and 6 are all for the entire rear caliper. There were other part numbers but the new part number is shown in red, which is the same number for all 3.