Turbo G8 owners check in.

[Robert@KBXPerformance]

Well just curious to see how many other G8 owners are on here that are turbocharged. I don't come across many others that are turbocharged so I figured why not post a thread and ask. I see so many Maggie owners out there but not many turbo guys. Speak up! I am also curious to see what kind of power and torque numbers you guys are putting down as well as any 1/4 mile times too.

I am running a mild Gen-TT based Garrett GT2871R system

Boost Level: 8.5psi
WOT AFR: 11.1-11.2
Total Timing: 14 degrees
RWHP/RWTQ: 500/570
1/4 mile ET: TBD

[parish8]

home made aps style. twin 60mm precisions. stock 5 muffler exhaust, stock cam, stock converter.

Boost Level: 9.9
WOT AFR: 11.1-11.2
Total Timing: 13
RWHP/RWTQ: 475/504(mustang dyno)
1/4 mile ET: 11.44@124.5(10.5psi)

[Robert@KBXPerformance]

home made aps style. twin 60mm precisions. stock 5 muffler exhaust, stock cam, stock converter.

Boost Level: 9.9
WOT AFR: 11.1-11.2
Total Timing: 13
RWHP/RWTQ: 475/504(mustang dyno)
1/4 mile ET: 11.44@124.5(10.5psi)



Nice 1/4 mile runs! I thought I had read that you were also on meth injection on LS1tech. Is that the case for those power numbers and ET or were those put down beforehand?

[Mlozano]

How come you guys chose turbo or procharge?

[Robert@KBXPerformance]

How come you guys chose turbo or procharge?

I chose to do TT's on the G8 because I like the efficiency of turbo's and I already have a Kenne Bell blown vehicle. I don't prefer the Maggies because they don't please me from an aesthetic sense and if I were to get a PD type blower then it would be a full on twin screw rather than a TVS roots. The turbo system does require allot more install time when compared to a Maggie blower or Procharger though.

[Mlozano]

Hmmmm... i see.

Thanks.

[parish8]

Nice 1/4 mile runs! I thought I had read that you were also on meth injection on LS1tech. Is that the case for those power numbers and ET or were those put down beforehand?

yes, lots of meth. those numbers/et are with the meth. duel 3" exhaust is next along with some 60lb injectors.

my hp numbers dont look all that great compared to some i am seeing but the mph in the 1/4 seems good to me and the ET isn't too bad considering a lowly 1.92 60'

[G8GT721]

APS Kit, 60# injectors, cat-back

Boost Level: Stock 7 psi
WOT AFR: 12
RWHP/RWTQ: 451/498
1/4 mile ET 12.270 @ 118

[Ktlplxm]

There would probably be more Turbo cars out there if the kits were readily available. Not to mention less Maggies if KB would get off their asses and design a kit

[Robert@KBXPerformance]

yes, lots of meth. those numbers/et are with the meth. duel 3" exhaust is next along with some 60lb injectors.

my hp numbers dont look all that great compared to some i am seeing but the mph in the 1/4 seems good to me and the ET isn't too bad considering a lowly 1.92 60'



Yep, an 11.4 ET at nearly 125 MPH trap speed is NOTHING to sneeze at. I could give two shits what a car pulls for numbers on a dyno as long as it performs at the strip. :)

So I assume you just stuck with stocker injectors and made up for the fueling deficit with the meth. I haven't sprayed meth in my car yet but I do have the FAST 65's in it. My next plans are to delete DOD and do a turbo cam, upgrade my connecting rod bolts, and do a meth injection system. I also have 2 Walbro GSS340 fuel pumps laying around from a previous project that I plan to swap into a custom fuel hat with a single -8AN line running forward to an A-1000 regulator, billet rails, and -6 return. I figure that will be a good resting point for a little while.

[Robert@KBXPerformance]

There would probably be more Turbo cars out there if the kits were readily available. Not to mention less Maggies if KB would get off their asses and design a kit



If I had more time I would build a few systems for some of the G8's local to me. I used to do that for a few other vehicles that have virtually zero aftermarket support. So far around where I am at there are not many people that have G8's let alone getting serious with them. :huh:

[G8GT721]

What are you guys stil using 5w30 for oil?
Oil Pressure?
Oil sender location?

[gman1227]

make a turbo for the V6(we dont have anything:()

[Robert@KBXPerformance]

make a turbo for the V6(we dont have anything:()


You got to have a tuning solution before getting forced induction.

I do not know what HP Tuners plans to do for the V6 G8's but I do know SCT (Superchips Custom Tuning) has been working their asses off lately to get their GM tuning up to snuff. We pulled and dumped my stock, N/A, and turbo tunes through an SCT X3 about a month ago so SCT support for the G8 GT is RIGHT around the corner. Hell I have been on vacation for the last 3 weeks so support might already exist by now.

You might want to give SCT a call or email their GM tech to see what they can do. It will be a bit of a process to go through but if you are serious and do some legwork with SCT they might just attempt to support the V6 G8's too. I know that as of right now SCT does not offer anything for the V6 G8 and might not for a while. But if you V6 guys start contacting them and are willing to work with them then you could get something going. Good luck.

After the tuning is happening then forced induction options can start being discussed. As of right now it would be sort of putting the cart before the horse.

[Marauder]

Do you get better fuel economy out of a TT than out of a supercharged engine?

[MGM GT]

There would probably be more Turbo cars out there if the kits were readily available. Not to mention less Maggies if KB would get off their asses and design a kit


Yepp... If only someone would design a single kit for about $5k it would sell!

[parish8]

What are you guys stil using 5w30 for oil?
Oil Pressure?
Oil sender location?


i use the cheapest full synthetic in the 5-30 weight. this week it was napa brand at 2.99 qt.

not sure what the oil pressure is but i did put restrictors in the lines to the turbos. it was smoking at ilde without them. oil sender location is right by the filter. you can get a nice t fitting from the factory that is ready to be 1/8" npt taped.

[Robert@KBXPerformance]

Do you get better fuel economy out of a TT than out of a supercharged engine?


Yes, you usually do.

[Ktlplxm]

Do you get better fuel economy out of a TT than out of a supercharged engine?

Speculative. Depends on the driver and the set-up. Some say the power adder cars get better fuel economy than NA cars, or that smaller engines get better mpg than larger ones because the BSFC is greater. Maggies for example, require all of 1/3 hp to spin; that doesn't equate to much mpg loss. Theoretically, a turbo should provide equal to slightly greater mpg, but its so minuscule its almost not noticeable (the added back pressure or restriction should be close to 1/3 hp as well). the other thing you have to consider is the fuel/spark curves in the tuning. Turbo's typically (but not always) have more heat related issues than SC's. Even with intercoolers the turbo set-up introduce warmer air into the engine. With some tuners, the easiest way to control the detonation is to cool it off with a richer mixture. IF it gets too hot or lean the chances of spark knock increase drastically so people have a tendency to put a little extra fuel into the mix to keep the temps down. Superchargers have this issue as well, but not usually to the degree a TC does. If you have a dialed in tune, and a well designed kit from someone like Robert, (not an ebay 3500.00 special) you shouldn't see a cruisin MPG decrease at all.

[G8GT721]

according to the DIC i get 18mpg around town, and if i go on the highway i go up to about 22-23mpgs at 75.

[Ktlplxm]

according to the DIC i get 18mpg around town, and if i go on the highway i go up to about 22-23mpgs at 75.

Wow. Thats surprising. i get about the same in town, but 26-27 on the open road at 75-80 mph.

[G8GT721]

yea, i haven't really been on any long trips of over 100miles highway before or after the turbos. I think the best on just a 93 tune was 24mpg highway which was just over 100miles. It really sucks down the gas though when you step on it, i do an 1/8 of a tank of gas on a 30mile trip to and from work.

[Robert@KBXPerformance]

Speculative. Depends on the driver and the set-up. Some say the power adder cars get better fuel economy than NA cars, or that smaller engines get better mpg than larger ones because the BSFC is greater. Maggies for example, require all of 1/3 hp to spin; that doesn't equate to much mpg loss. Theoretically, a turbo should provide equal to slightly greater mpg, but its so minuscule its almost not noticeable (the added back pressure or restriction should be close to 1/3 hp as well). the other thing you have to consider is the fuel/spark curves in the tuning. Turbo's typically (but not always) have more heat related issues than SC's. Even with intercoolers the turbo set-up introduce warmer air into the engine. With some tuners, the easiest way to control the detonation is to cool it off with a richer mixture. IF it gets too hot or lean the chances of spark knock increase drastically so people have a tendency to put a little extra fuel into the mix to keep the temps down. Superchargers have this issue as well, but not usually to the degree a TC does. If you have a dialed in tune, and a well designed kit from someone like Robert, (not an ebay 3500.00 special) you shouldn't see a cruisin MPG decrease at all.



The key is having a well dialed in tune. You could have the best hardware in the world but if the tune isn't dialed in to allow decent gas mileage then it all doesn't matter. Hey Ktx, one thing I do want to mention is that you talked about an engines tendency to want to knock with forced induction especially while lean. While that is very correct especially from a WOT standpoint, you would have to assume that if people are talking gas mileage then it would be safe to assume they are off of the loud pedal. This would mean they are just cruising at or very near a stoich AFR (14.64:1 AFR) and under very light load too. There will be no need to dump additional fuel into the cylinders to cool the combustion chambers to minimize detonation. What you refer to is something used primarily when the vehicle is in open loop fueling while WOT. In those par throttle cruise conditions the intake aircharge temps will not be up any considerable amount (within a few degrees of ambient). Even under WOT pulls my IAT's stay pretty darn low. With a proper intercooler setup turbo systems will usually introduce less heat into the intake aircharge than a positive displacement blower such as an Eaton roots, TVS roots, Kenne Bell twin screw, or Whipple twin screw. The AWIC's can be very efficient in the PD type blower setups but it is hard to fight heat soak when the blower is mounted directly above the cylinder heads.

[Robert@KBXPerformance]

yea, i haven't really been on any long trips of over 100miles highway before or after the turbos. I think the best on just a 93 tune was 24mpg highway which was just over 100miles. It really sucks down the gas though when you step on it, i do an 1/8 of a tank of gas on a 30mile trip to and from work.


Your tune could probably be tweaked to gain a little more mileage out of it. Right after the car was wrapped up I averaged right around 27mpg on a 300 mile roadtrip and wasn't driving like a grandma at times. :) I recently took a 120 mile round trip to Mobile, AL for a doctors appointment and averaged 28.7mpg with a small amount of mixed in town driving too. This was done mainly on cruise control at 70mph which by my tests yielded the best results. When I tested it at 75 mph the mileage had suffered by about .5mpg-1mpg or so. The best speed to attain the highest mileage will depend on the setup of the car including the tune too though so what works for me may not work for you.

[mystic98ls1]

STS Twin turboed
7.5 psi
512rwhp
543rwt
Meth numbers still to come and 9 psi
And my car still gets atleast 25 mpg

[Ktlplxm]

The key is having a well dialed in tune. You could have the best hardware in the world but if the tune isn't dialed in to allow decent gas mileage then it all doesn't matter. Hey Ktx, one thing I do want to mention is that you talked about an engines tendency to want to knock with forced induction especially while lean. While that is very correct especially from a WOT standpoint, you would have to assume that if people are talking gas mileage then it would be safe to assume they are off of the loud pedal. This would mean they are just cruising at or very near a stoich AFR (14.64:1 AFR) and under very light load too. There will be no need to dump additional fuel into the cylinders to cool the combustion chambers to minimize detonation. What you refer to is something used primarily when the vehicle is in open loop fueling while WOT. In those par throttle cruise conditions the intake aircharge temps will not be up any considerable amount (within a few degrees of ambient). Even under WOT pulls my IAT's stay pretty darn low. With a proper intercooler setup turbo systems will usually introduce less heat into the intake aircharge than a positive displacement blower such as an Eaton roots, TVS roots, Kenne Bell twin screw, or Whipple twin screw. The AWIC's can be very efficient in the PD type blower setups but it is hard to fight heat soak when the blower is mounted directly above the cylinder heads.

I agree, that's why I mentioned the tune being a key factor. There are a fair amount of shops that still like to keep things a little rich even at cruising conditions (we've all ridden behind these cars before and been able to smell it) I'm pretty sure this why both you and I keep using key words in a sentences such as "optimal","ideal", and "proper". In a well engineered system (as I mentioned earlier) these things shouldn't be an issue. Unfortunately, a high percentage of people always seem to cheap out and ignore those key words. Had there been a proven reliable system available for my vehicle, I would have purchased it in a heartbeat. I'm of the opinion that a quality turbo kit should be in the 7K range. Any higher than that and the designer is being greedy and attempting to turn a quick profit. Any less, and they are cheaping out on parts.

[Tempest2000]

demand doesn't help the G8 in terms of kits... not enough of us to get the volumes up and the pricing down. could try to take a kit for the camaro and adapt it if you had the time...

[Mike P]

* bump *


I was doing a little searching to see who on this site is running turbo set ups..... :)



...

[HoldenSS]

Is there are aftermarket single turbo or TT for the G8GT ?

[Ktlplxm]

Is there are aftermarket single turbo or TT for the G8GT ?

Do a quick scan of the Power adder section, it should help you out

[Devilish34]

Search is your friend check New Era's web site

[Jinx]

Ok, I love to see at least a set of Parish's "header to turbine side", "downpipe", and wastegate flex piece. That seems to be the ticket parts. The charge pipe/intercooler pipe would seem to fall into place once you figure out the angles on each of his bends (some of the most redneck of DSMers made an art out of this). I know APS claims that the vertical cores have less restriction; but I like to see what a run of the mill, affordable horizontal core intercooler can do. I like how Parish's APS style fits in the place of the stock cats, where the there is already heat shielding and uses the stock manifolds.