Posts by TravAZ

Any Slingshot adapter will work.

I like the looks of the NRG one over the Assault, but that's just my preference. There are several options out there now.

I'd personally skip the oil cooler, but it wouldn't be a bad item to have if you are set on getting one. I've run several track events in really high heat and haven't had any issues burning up the oil. I do change it more frequently though and run a good synthetic.

Leave your O2 sensor right where it is. There is no reason to remove it or mess with it. If you leave it unplugged or disconnect it, it will mess up your closed loop tuning.

Like iNewton mentioned, just have a shop weld a bung in for the AEM wideband sensor 6-10 inches after the hot side of the turbo.

That code is explained below...
This code is just a timeout feature for EPAS after sitting for over 5 minutes jamming to music (etc.) in accessory position, or at least with key on and engine not running also. Code will clear itself after a couple of restarts.

Make sure you keep the stock O2 sensor where it is. It is still working with the ECM in closed looped sections on the tune. You will need to add another bung for a wideband sensor 6-12 inches after the turbo in the exhaust.

I personally like the AEM Failsafe gauge. It shows both boost and AFR reading on one gauge and also records logs. Logging will be really important to you, if you are going to swap motors and raise boost. It is vital info in making sure the tune is correct and that boost psi is in line to what you expect with wastegate spring changes.
AEM Failsafe

I haven't seen anyone running one yet. I personally think it is a waste of money on our application. Why...?

Boost levels aren't really that high.

Newer turbo technology as we see with these oil cooled Precision turbos is much better than older turbo kits that used turbo timers.

Turbo is in a good spot to stay pretty cool.

You can easily manage the cooling of the turbo yourself. You really only need to cool the turbo after really hard driving. A couple minutes of low boost driving or idling and you're good to shut it down.

I don't even think any vendors are selling a turbo timer option / upgrade.

It's really important that you get a AFR and boost gauge installed. These numbers are critical in diagnosing issues and overall performance of the machine. AEM Failsafe is a really good choice.

It is very possible that your issue is related to the port and polish. Probably not on the intake manifold, but others have had weird performance issues with the throttle body port and polish. I'd make a new thread and see if people can chime in that had / have a similar issue.

Sounds like you're on the most current and correct tune.

A few of us on the west coast are running 10 -14 psi of boost and are not having any clutch issues. These are hard miles with myself running several tracks days. If you are going to pull the motor and shoot for a number over 350hp at the rear wheel, it wouldn't hurt the just replace the clutch. For experimental purposes (this is if you are going to build your stock SS motor and put it in this winter) it would be awesome to see you push the stock clutch and find the breaking point before doing the DDM upgrade.

I also haven't heard of anyone having fuel delivering issues at the boost level listed above on the side of the country. Most people have realized not to push their vehicle hard under 2 bars of shown fuel on the gauges to make sure not to have a sloshing issue. I have ran my vehicle hard on the track on the way down to 1 bar and haven't seen any issues. I wouldn't do it on purpose though if it is easy avoidable.

What you are explaining above is most likely a fuel enrichment / tuning issue. We have made some adjustment to the Alpha 2bar tune lately to help with some fuel bog issues that some people are having. When it "bogs out", look at you AFR number and tell us what your are seeing. If you are seeing low 10s or numbers in the 9s, you probably need to research to make sure you are on the most current Bob tune for this setup.

You are right man. Alpha leaves the other springs out because they don't want someone messing it up and blowing a motor. They may have extras laying around. Id email them or call the shop. Or you can buy them online.

I have changed my springs a couple of times. It's not too bad, after you've done it once. I recommend buying 2 long bolts that assist you in getting the cap secured. Look at the ones you pull out and buy 2 around 1 inch longer. You'll understand why these longer bolts are so helpful when you go to put the cap back on.

I've talked to Bob quite a bit about running at the high end of 2 bar and the possibility of having to go to a 3bar setup. He says you can actually run above 2bar boost (14.7 psi) and the tuning would still be ok without switching to 3bar. You could probably run two bar and go up around 16 psi if you think the motor will hold.

Would the tune need to be changed from what you're running now if you run 15lbs of boost? Maybe. It really depends on how your AFRs look as you start climbing the boost ladder. It's possible the tune would work just fine. It's also possible some fuel would need to be added at boost levels over 12lbs.

I'd run the red and natural first. That's what "should" be installed right now if you're running the header and most recent Alpha tune. Then go green and see how everything looks; should be fine with 06-07 and good head studs. Then there is green and natural. Couple of other steps. The last step would most likely be green and yellow.

Rough / quick guide on boost numbers to expect from what my machine does...

Red - Precision says 6psi max; actual with header is around 8 to 8.5psi.

Red and Natural - Precision says 7.5psi; actual is 9.5 to 10psi.

Green - Precision says 9psi; actual is 11 to 11.5 psi.

Seeing a trend here...? So we can just take a blind guess on where the max psi would be on 2bar tuning.

The green, yellow, natural combo should put you right between 15-16psi.

Just keep in mind, this is how my machine acts with a short tip on the Alpha side exhaust. Also keep in mind the boost levels get around 1psi higher than what you typically see when flying in 4th gear. At over 6000rpms, I'll see 11lbs of boost on some laps - 9.5 to 10psi is what I see normally.

Hopefully this info is helpful. I like the direction you are going and hope to see good results.

I think you have a great idea, especially considering you can swap the motor yourself. It wouldn't be the end of the world if you blew a $600 motor anyways.

What turbo kit are you running and where are you located at?

He stated pulling a 2006 motor. It is my understanding that everything in 2006 and 2007 is forged.

Now finding one with low enough miles just to swap it may be a long shot...

Quote from mniron

I believe 10k gets you a base 2 wheel rear conversion only, you would need another chunk of change for the V8.

Bingo.

$10k for a quad kit and another chunk for the LS3 swap.

Even at $20,000 (guessing), you are getting quite the package! You could have a $40,000 vehicle and just drive circles around pretty much everyone else.


On a different note, I would love to see some small fenders over each wheel that have the lines of the front hood portion the covers the wheels. A little protection and the machine would look much faster when parked.

Quote from Bugzilla

@Dave@DDMWorks

I agree. I have not seen any detonation issues with the iridium plugs. I actually think they help with detonation. It is more of a spark plug heat range issue that will cause detonation to happen. (or just a bad tune)

Non iridium plugs that would be comparable are the NGK TR7 for boosted and the TR6 for NA applications. Some people even use the TR55 for NA applications. Not sure what the 4 digit part numbers are off the top of my head.

@Bugzilla the NGK TR7s are most likely too short.

You will be in the same boat I was when I switch my plugs the first time and didn't realize the "reach" difference. Good thing I didn't mess up the head at my last track event. TR7 specs below...

Shell

• Thread Size: 14mm
• Thread Pitch: 1.25mm
• Seat Type: Tapered
• Resistor: No
• Reach: 18mm (.709")
• Hex Size: 5/8" (16mm)
• Terminal Type: Removable Nut
• Overall Height: ISO
• Gap: .031" (0.8mm)

Quote from Dave@DDMWorks

Since the stock NGK non-iridium spark plugs are LTR5GP, then the 6 heat range plugs would be an LTR6GP, but that is not available from NGK, neither is a LTR7GP.

That plug that was listed for the HAHN setups is a LZTR5A-13 and so the 6 heat range would be a LZTR6A-13, which is not available either.

I would have to do some searching to come up with a copper plug with a 6 heat range in the same length, nothing right off though. As for the iridium causing detonation, that is not something that we have seen at all, typically it works really well since the tip is so small on the iridium it runs cooler at the tip and is less prone to detonation.

I guess through my experience so far, it has been actually backwards on my machine.


I have been told this by a trusted source, but I am not sure what value it holds. Paraphrasing what he told me below...

"Iridium plugs tend to heat up much faster under full boost conditions because of the small tip. It is like heating up the pointy end of the pencil instead on the eraser end. You can easily see which one will get hotter faster. Because iridium gets so hot so fast under full boost, we will see many machines on the dyno have detonation issues and also make less power. On the positive note, iridium plugs will last much longer in boost applications compared to "standard" copper plugs."

Another internet source on the subject... (is it reliable, who knows...?)

"I have kept quiet for a long time about the iridium plug debate on here but I am going to throw in my $.02... These findings are based on on-time data logging and research on a turbo'd 400whp audi a4 (2871R).

Copper is one of the best conductors of electricity and heat, but they just plain dont last mileage wise. Iridium & Platinum last 10 fold longer thus the reason why auto manufactures use these. Coppers can last 5K miles if the engine is operating optimally. Platinum and Iridium plugs have a center electrode (fine-wire) that is thin. Under high boost application they get so hot they will begin to "heat glow" and cause premature ignition in the combustion cycle (pre-ignition => detonation) unless they were properly designed to pull the heat. This is a problem for all of the turbo guys running high boost. Copper on the other hand, has a much thicker center electrode, on top of that, the copper material is able to dissipate heat from the combustion chamber fast enough to keep the combustion temperatures lower. Coppers use thicker electrodes simply based on the fact that they can easily jump the spark, whereas platinum and iridiums will require a fine wire to better direct the spark to prevent misfires.

Remember the TWO primary functions of a sparkplug:
1) To efficiently ignite the A/F mixture without misfires (gap..etc)
2) To pull heat from the combustion chamber into the head, where the cooling system should dissipate that heat. (Heat Range)

A platinum/Iridium plug in a colder heat range usually runs just as hot as a copper in the standard heat range when under high stress. So many people will use a Platinum/Iridium plug TWO steps colder to counter that. But using a plug that is 2 steps colder, will lead to two things:

1) More prone to carbon-fouling on "normal driving" where EGT's are kept low. (Plugs must stay above 550C Deg to burn off excess carbon deposits to "self-clean")
2) As a result, loss of horsepower from a less efficient/inhibited spark.

You need a plug that is actually "hot enough" to ignite the A/F mixture as hot as possible to get the most efficient combustion, as well as burn off carbon-deposits (~550C deg), and yet cold enough to prevent pre-ignition when compression is high (< 870C Deg)."

The real test for me is going out and driving my machine hard with the new copper plugs installed. I am pretty sure this is the fix, but won't know until I get up really early and drive it or go out in the 100-115 degree heat. If I don't hear detonation, I will stick with the copper plugs and be OK with changing them every 10,000 miles or so.

@Dave@DDMWorks @Bugzilla

If guys don't want to run iridium plugs in NGK heat range 6, what would be the non-iridium replacement NGK plug?

I feel like their has been more detonation issues with the iridium style plugs. Maybe it is just me though....

Quote from MACAWS

The Hahn Turbo set up recommends NGK 4306

Here are the details on this plug. Seems like a hot plug to me when pushing over 250hp. I would also think the gap is pretty large...

Product Details

For the Alpha turbo kits we are using one of the below set of plugs...

• Iridiums that come with turbo kit - NGK: BKR7EIX11
• Copper / Standard Option - NGK: 92038 - LFR7A

If you are going to run anything different, pay special attention to the heat range, gap, and length of the plug. I was running some other NGK 7 heat range plugs, but realized they were much shorter than what should be in there.

Quote from rabtech

Every turbo system should have a boost and AFR gauge. I think DDM carries the AEM Failsafe gauge. It is easy to read and it is very accurate . And as an added bonus it has a 3 hour data logger. Just install the free software and download the data via the USB cable attached to the gauge.

The stock engine is pretty dang tough. I forced 10.2PSI into my slingshot for a while.. I did notice several times that my fuel ratio would go rather lean. If I had not had a gauge I would have probably kept my foot in the throttle and who knows... It could have blown. I have since added a fuel pump and I am hoping my problem of running lean at higher boost levels has gone away. I will know soon.

There has to be some common sense when running these boosted engines,, Even at low boost you can kill an engine if you get a tank of fuel that isn't up to spec. Or if you lug it around or if it knocks for some reason. You have to use your ear and your butt to get a sense of what the engine is doing...

Agreed. Most of the engines are pretty dang tough. I consistently see over 10lbs of boost on the track. Flying in 4th gear it will go over 11lbs.



Unfortunately, some people get a bum motor and/or don't get their system installed correctly. It is not hard to blow a motor if your stuff isn't hooked up correctly and you don't know what to listen/look for.

I am sure the DDM built motors will be sweet! Looking forward to seeing them out in the wild!

This is the problem I ran into for several months. You need to find out where these organizations are HQ'd at and visit them in person with the machine. Or, stop by one of the events and show the organizer and tech team the vehicle. Make sure you are explaining the below for this purpose...

It isn't a motorcycle (it is an autocycle) and it would NOT be safe to run with 2 wheel motorcycle clubs/groups.

Ask them - What is the difference (safety wise) from the Slingshot to a Shelby Cobra or a topless Miata?

Explain that other people in the country are currently allowing Slingshots to run on the track with cars. Show the youtube videos.

Mention you don't care if you are in a points class and see if they will check with their insurance agency on allowing it.

Be willing to buy and use arm restraints.


It took several NOs before I got one group to give us a yes. Good luck!

After several months of NOs from several different organizations, I was able to get the Slingshot approved to run with the ProAutosports group. These are mostly in AZ, but are worth the trek for people in neighboring states that want some track time. They are not Slingshot only. You will have to run through their New Member program for 1 day and then you are out running with the other cars. There are several groups bases on experience and speed. Some groups are pretty mild, and other street groups, like Green, are full of fast cars.

I am attending one on Friday nights under the lights are Wild Horse Pass.

More information can be found at their website. They have several events during the year.

http://www.proautosports.com/

It will be interesting to see the first turbo people install this "heat kit" radiator shroud. My guess is, that it will be a nightmare because of the additional turbo plumbing and intercooler.

I am guessing it will take some cutting and some additional curse words. Hopefully not though...

Quote from Leadfoot

Original cost $300.00, will sell for $125.00 + shipping.
Includes coil over spring of course.

I would be interested in the belt if you want to let it go for cheap.