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,
Dave
Display MoreAs I started this thread back on March 8th I was still doing some research and looking to hear from others experiences. If you have not read by now I did end up going with the DDMWorks stage 1 turbo kit.
There were a few things that lead me down that road over other vendors. One was the overall High community recommendations for them based on experience, not only the quality of builds but the level of customer service. Big shout out to Dave as he stepped up big in my mind at resolving any issues I had. 1 was a cracked fitting which possibly could have been done when we installed it. He sent not 1 but 2 replacements to me over night. The first 1 got lost and never showed up so he sent me another one Last night that came today. When starting the install Angie had told me he was traveling when I called with some other non related questions. Not only did he answer my txt I'm pretty sure he gave me a call at some point as well while at the airport. Overall all I would rate my technical skill set in the garage 6/10 and I had no issues installing this kit. Directions were clear as can be with pictures. So again THANKS DAVE!!!!!!!
For anyone else looking into a turbo the other reason I went with DDMWorks over other vendors came down to Exhaust options. My wife last year did nothing but complain about exhaust fumes. When I bought the bike used, it came with a Alpha exhaust with electronic baffle. So I ordered a Welter Rear exhaust for this kit. However after installing and firing up the one that came with the kit I ended up canceling that order. It sounds great with the DDMWorks exhaust and also during the install I noticed that Alpha exhaust sat flush with the underside of the slingshot. The DDMworks exit sits probably 2 inches lower.
All I have left to do is put the hood back on which I'll probably do tonight or tomorrow. Even though we got some Snow last night I still took it out briefly today and OMG what a difference. I can't imagine the people running Stage 2 kits with tuned motors. I can now in 4-5th gear give it the gas and she will actually go. Before as others have complained it really lacked some passing power in the higher gears at low RPMs. Hopefully tomorrow since its going to be almost 60 I'll take it out for a longer ride.
If anyone has questions feel free to reach out. I attached some pictures of the finished install.
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!
Dave
I'll be there. Stalking up on the green caps as we speak
You are stalking them? 
Dave@DDMWorks started a new event:
QuoteLooking forward to this one!
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.
Display MoreDave@DDMWorks wokka Kyle D FunCycle Edward Neal SoCal MACAWS Bigdog BKL
My scooter used to have 710 hp (peak 1,246 hp for about 1 second) from a hybrid system I rigged up with a competition drag racing electric motor. LOL
Thought you guys might get a kick out it!
I made a special coupler to engage the electric motor into the belt drive weight reduction holes.
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
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,
Dave
Display MoreDoes the EVAP Solenoid line at the Intake Manifold have a one-way check valve?
Looks like the DDM EVAP delete kit comes with a rubber cap that goes to the intake manifold. But my intake manifold may be between 15-25psig.
I could remove the intake manifold and put a boost rated "Airborne" custom cap if needed.
Would I need the DDM EVAP delete kit with a Haltech ECU, I believe not?
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.
Display Morelooking at this 2015 parts list...
.
which number is the complete Caliper. #1, #5 Or #6....and why 2 numbers with 5 & 6.
I don’t want a rebuild kit....I want the entire unit.
I found the answer to my brake failure light.....over the winter brake fluid leaked out of the caliper somewhere. It’s eating the powder coating off the rim.
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.
Modified Welter 2.5" exhaust. Still no fumes, but man does this sucker shoot flames now.
Before:
After:
Pictures or it didn't happen
I love driving those sidekicks at night after and install, so much fun lighting up the road behind you 
We have some awesome customers!
Yesterday we did a 95mm pulley and Stage 3 cam install on a customers Slingshot here and at the same time upgraded the customers coil cover to a powdercoated version. He had a bare aluminum one and we asked if we could post it on the forum for free and he was all for it.
So, this is a aluminum DDMWorks coil cover, all installation hardware is included. Just pay for shipping and it is yours. First person that emails Angie@ddmworks.com and claims it, gets it.
If you are expecting a perfect coilcover for free, this is probably not for you It has a couple little scrapes, etc, but still looks very good.
You can drop the passive-agressive BS at any time, You've been that way to me from day one and it's pretty annoying.
Anyone that looks at the results can easily tell you were only the fastest because kyle wasn't there. Your 1/2 speed wasn't even close.
REGARDLESS....
This thread is about a guy being fed false hope that he's going to make a true 500whp on pump 93. And somehow people have convinced him that he just needs enough pressure? It's absurd.
There's a hundred different calculators online that convert mass fuel flow into approximate HP. Witchhunter is a good start. However, flowing 500hp worth of fuel does not mean you're going to make 500hp; those calculators are assuming you're NOT knock limited. It's disturbing that people would sit here leading him on, as if buying the right fuel system parts is somehow going to get around that.
Not sure if you have me confused with someone else, but this thread is the first time I have ever responded to any of your comments on this forum.
As to wether Kyle would have been faster or not at the same track on the same day is debatable since traction is going to be a big factor in the 1/2 mile speeds and that traction changes from track to track. Kyle set his record at one place, we set ours at another place, he may have been faster at the event we were at, just as we may have been faster at the event he was at.
That also brings up another point with 500hp at the wheel builds and traction of the rear tire on the street. From all the 425+ rear wheel HP builds we have done here, at that power level usually you can break the rear tire loose at almost any speed in 4th gear. So if he makes 485HP or 515HP at the rear wheel with all the weight he has removed from that Slingshot, there will be even less traction on the rear tire and he will not be able to put that power down anyway. Once he gets to the top of 4th gear, the aero loads with that exposed frame is also going to be pretty high.
Even at a road course like the racetrack in Savannah we were at this last time we were only running 17psi on the 7163 with a Toyo R888R on the back and stayed in 4th gear the entire lap since we could break the tires loose at any RPM above 2200. Until traction is taken care of you can make all the power you want, but the Slingshot will not be faster. In the video you can hear the rear tire breaking loose coming off the turns and on the straight -
Hi all...I have a SC kit...small pulley...can I change the cams only?
When installing the cams you do also need the ECM recalibrated for them and we suggest swapping out the HLA's at the same time as the cam install. Let us know if you have any other questions about the install.
Dave
did you even read what I said? If it’s enough to get the required mass flow, then it’s enough.
kyle is the fastest in the world with a ~33psi differential.
Real world trumps keyboard thumping.
Is that a Yes to both questions?
ARM with your tuning at ZZP, Kyle only has the fastest speed in the 1/2 mile for now, a great accomplish for sure. However, maybe you are not aware we have a faster speed recorded in the 1 mile and faster than even Kyle thought anyone would go before the event.
Probably a valid concern. I played at the track one night. Made 3 passes with a best of 8:05 on a legal 1/8mi. 60' times were in the 1.8's and it slipped a couple notches on the belt. That was with 10lbs boost on a single rear tire.
I can tell you from expreience that the synchronizers are tender. Mine has a gimpy 3rd gear synchronizer now. Don't affect up shifting but you have to burp the throttle down shifting. It's a pain in butt. Looking to buy another trans so I won't be down while I repair this one.
Yeap, that has been the most common issue we have seen with the transmission dating all the way back to the Solstice/Sky, they basically have the same transmission in them. With those we would also see the 3rd/4th gear synchro issue that Ghost has. As for actual breaking apart failures, those have not been super common in the Solstice/Sky world with much heavier cars. Also, the AR5 transmission used in the Slingshot is used by a lot of guys as an upgrade in things like the Supra, just FYI.
Hope that helps,
Dave
also, this talk of atomization at high boost is kind of silly when you're spraying on the back of a closed valve any time you're past 25%idc. the fuel mostly vaporizes from the heat of the valve and the remaining liquid is atomized as soon as the valve cracks open. Hell OEMs have been spraying on the back of the valve on PURPOSE for decades in a lot of cars.
Yeah you need a usable pressure differential, but it's simply because you have to be able to hit your mass flow. These cars/bikes need a feed line upgrade long before a referenced regulator IME.
From tuning experience at ZZP then, the fuel atomization on a boosted 2.4L engine running an EFR 7163 at 25psi of boost pressure using #80 fuel injectors with a 33# pressure delta is considered acceptable? You consider 33# of fuel pressure a usable pressure differential at the fuel injector?
Hello all. My new to me SS is being delivered today! YIPPEE. Hoping there's an idea out there to make it easier to drive for my better half. My wife is small (I'd say short but she might read this :). She don't hit 5 foot with shoes on. Is there a safe option for extending the pedals/bringing them closer to the driver? Thought about pedal extenders, but don't want to create an unsafe condition. Anyone using these? Thanks.
Edit. I'm 6'2", so I'm looking for an option I can leave in, that brings them a couple inches closer that I can live with too.
Have you considered something like this -
\\
Just kidding
I haven't seen anything out there that can extend the pedal that much that could be easily swapped out easily. We modeled up some pedals early on that did extend the gas pedal out a little bit to match up with the brake pedal and make easier heel/toe driving, but no where near as far as you would need.
I did a quick search and came across this, no idea if it would work or be safe, but it is on Ebay, so it must be
https://www.ebay.com/i/2645768…3rSwQYEAQYASABEgK40_D_BwE
Also found this - https://www.indemedical.com/Su…3rSwQYEAQYAiABEgLL9vD_BwE
Hope that helps and welcome to the forum!
Dave
Display MoreKyle D Definitely some golden info in there. Thank you!
(FUEL) Regarding manifold pressure referenced fuel pressure regulator, I believe as manifold pressure increases then fuel pressure differential across the injector decreases.
Example:
Provided 60psig = 74.7psia and estimating maximum 26psig boost
(NA) 74.7psiaFuelRail - 14.7psiaManifold = 60psiaInjectorDifferential
(Boosted) 74.7psiaFuelRail - 40.7psiaManifold = 34psiaInjectorDifferential
Although injector pressure differential is not super linear with respect to flow vs pressure changes. Assuming a linear relationship, we might need bigger injectors with 76% greater flow rating to achieve the same job, without the application of a manifold pressure referenced fuel pressure regulator.
I think ECU tuning injector pulse width and maintaining a smooth idle may be easier by avoiding 76% larger injectors and providing a constant injector pressure differential.
(AIR) Regarding Max whp on 25-27psig, I think I am are running about 300whp at 9psig (23.7psia) at current unknown temp.
Example:
At constant manifold temp, changes to absolute manifold pressure is proportional to changes in air mass.
Assuming I can maintain similar manifold temp, through extra cooling, at 9psig (23.7psia) to 26psig (40.7psia).
26psig of boost will be about 515whp, potentional air mass.
Do these values seem logical?
Kyle D Great information and I appreciate your feedback, on this journey
The other thing with the respect to fuel injector sizing that is not mentioned above is RPM of the engine. As engine RPM increases the time for the injector pulse width (intake valve opening) gets shorter and shorter, so this all becomes even more important as engine RPM goes higher also and needs to be considered also.
Any recommendations on the fuel system components to match 26psi boost? I don't think there was anything posted on the website.
I'm assuming Rabtech was running 511whp on 93 octane, considering the 80# injector, if I'm putting the puzzle pieces together correctly.
I can get you the list of what we did to our Slingshot for the system, shoot me over an email - dave@ddmworks.com
As far as I remember rabtech was on 93 octane for that run, I am sure he can answer for sure.
Display MoreWas having difficulty finding a thread regarding Fuel Pressure. Point me in that direction and I will add to it.
What is stock Fuel Pressure? (about 58psi?)
rabtech Dave@DDMWorks Kyle D and All,
- I'm trying to avoid E85, for a couple reasons... At what HP running 93 octane will I need to upgrade the fuel pump?
rabtech I know you mentioned 450whp no problem (511whp peak bursts), but then I notice a thread where you replaced the fuel pump and I think you are running 93 octane?
- At what HP/BoostPressure running 93 octane should go with a manifold pressure referenced fuel pressure regulator?
- What is recommended constant fuel pressure at 500whp?
- What is recommended injector size for suggested fuel pressure at 500whp?
Note: I'm aiming for 500whp (on my current DDM Stage 3 Turbo) with future DF Project 324 8.6" LSD to lay it down.
Kyle D, Thank you for the previous data which I will continue to refer to.
Stock fuel pressure that we have seen is 58psi on most Slingshots we have tested.
I would say it is more of a boost pressure thing than a HP rating for when you will want to upgrade the fuel pump, not really need to change it. As you increase boost pressure in the intake manifold the pressure delta across the fuel injector (fuel pressure minus boost pressure) starts to decrease, therefor for the same injector pulse length, less fuel comes out of the fuel injector, this then requires longer and longer injector pulse lengths at higher boost pressures. by going to a boost regulated fuel pressure setup on higher boost setups, it makes tuning much easier and also the injector pulse length on the same set of injectors can be kept shorter allowing more headroom in the injector. The other thing that lower fuel pressure delta causes is poor atomization of the fuel compared to higher pressure. You can ask rabtech of his experience with this, but we have basically the same setup and were able to get 80# injectors to work very well at those power levels without going completely static.
That being said, really as low as 15psi I would say you will start to see a benefit from going boost regulated setup on the fueling, not needed, but it is nice. I would definitely recommend it over 20psi, otherwise your fuel injectors are basically only seeing 38psi of pressure, which sucks for fuel atomization and flow.
On all of the boost regulated setups we have done, we set the pressure to 58psi.
We are running 80# fuel injectors on ours and it is working great.
As for the EFR 71623 in the Stage 3 kit, even if you run it wide open with no wastegate control you will not see over 26-27 psi at the airflows you will be seeing, rabtech has done it and we have maxed it out also, it just can not flow more pressure than that on the 2.4L.
Give a call or let us know if you have any other questions,
Hope that helps,
Dave
