Pontiac Solstice Forum banner

1 - 20 of 39 Posts

·
Registered
Joined
·
459 Posts
Discussion Starter #1
What kind of gas mileage are you getting from your LS3 V8 Kappa ( Sol or Sky)? I have LS3/480 conversion and my highway mileage seems to be around 25MPG at 60mph. Anyone getting more?
 

·
Super Moderator
Joined
·
16,392 Posts
Mine varies between 13 mpg and 26 mpg. Instantanious mpg has been as high as 33 on level ground in 6th at low RPM. (1800-2200)

Mine also likes to run at 200 - 220 F and occasionally drifts upward to 235. Max I have seen is 237 on a 100 F day in stop and go traffic.

I have been told that these temperatures are normal and that the upper limit is 260 F.

Also the high ambient temps and 225 F motor / transmission means a very HOT cockpit. I am applying thermal / sound insulation so the wife stops jumpinf overboard but I am interested in your experience as well.
 

·
Registered
Joined
·
164 Posts
I get an average of 14 mpg in the city and 22 mpg on the interstates as long as I keep it under 70 mph. Anything faster then that and the mileage drops off significantly.
Temp runs about 210-215 in the city during summer and 195-200 out on the highway.
 

·
Registered
Joined
·
459 Posts
Discussion Starter #4 (Edited)
My temperatures run around 196 on the highway and can climb to 220 in the city on a 98 degree day with A/C on. As soon as I get on highway, temps return to the 196 area. I seem to get around 14mpg city, if I don't push it too hard between traffic lights. I have seen my instantaneous mileage go as high as 34 in 6th at 1400 rpm on the highway, but drops immediately if I pick up a few rpm's. I get around 22mpg at 80 mph, which is 2000rpm with my setup. I also get tremendous heat coming from trans tunnel. It can actually burn my right calf if I lean it against the hump on a hot day. Will have to put insulation in there somehow.
 

·
Super Moderator
Joined
·
16,392 Posts
My temperatures run around 196 on the highway and can climb to 220 in the city on a 98 degree day with A/C on. As soon as I get on highway, temps return to the 196 area. I seem to get around 14mpg city, if I don't push it too hard between traffic lights. I have seen my instantaneous mileage go as high as 34 in 6th at 1400 rpm on the highway, but drops immediately if I pick up a few rpm's. I get around 22mpg at 80 mph, which is 2000rpm with my setup. I also get tremendous heat coming from trans tunnel. It can actually burn my right calf if I lean it against the hump on a hot day. Will have to put insulation in there somehow.
Sounds just like mine but for the idle difference.

I am going to start insulating this weekend. I have header wrap, muffler thermal blankets and self stick sheet insulation. I am going to check the transmission tunnel at the firewall and see if there is a way to add some insulation there to cut down on the flow of heat directly into the transmission tunnel.
 

·
Registered
Joined
·
1,195 Posts
I get an average of 14 mpg in the city and 22 mpg on the interstates as long as I keep it under 70 mph. Anything faster then that and the mileage drops off significantly.
Temp runs about 210-215 in the city during summer and 195-200 out on the highway.
Noticed you didn't complain about cabin temps. Did Mallett install heat insulation? Was Mallett still in Berea, Ohio when your car was done? That's my home town. They do nice work, almost went to work for them. Thinking of doing a V8 Sol down the road. Rebuild an LS engine and pick up an older Sol. I won't do this to my coupe :nonod:
 

·
Registered
Joined
·
1,195 Posts
Rob and cooper did you guys trim back any of the styrafoam behind the grills. I've noticed the NA cars have more grill hoses blocked by foam than a GXP.
 

·
Premium Member
Joined
·
686 Posts
Rob and cooper did you guys trim back any of the styrafoam behind the grills. I've noticed the NA cars have more grill hoses blocked by foam than a GXP.
I'm thinking about doing this to my 2.4L Stage II. I feel like the intercooler isn't getting enough airflow as is. I also want to add the GXP style air-splitter that norm sells.
 

·
Registered
Joined
·
164 Posts
Noticed you didn't complain about cabin temps. Did Mallett install heat insulation? Was Mallett still in Berea, Ohio when your car was done? That's my home town. They do nice work, almost went to work for them. Thinking of doing a V8 Sol down the road. Rebuild an LS engine and pick up an older Sol. I won't do this to my coupe :nonod:
Mallett was still in Berea when they did my Sky, and I never noticed any increase in cabin temp after the conversion, In fact, I've never even used the air conditioner. I never drive with the top up. The only time I put the top up is to support the cover when It's stored during the winter months.
I am very happy with their installation, very professionally done. :dthumbs:
 

·
Registered
Joined
·
10 Posts
Hey sorry I'm off topic, but I just finished my ls2 swap in my solstice (gets great gas mileage) and I was wondering what differential you guys were using? I swapped mine for the 06 cts v 3.73 and it seems like the axles might be a little short.. Sorry im from northern california and theres nobody around here to ask for solstice help. Any advice would be greatly appreciated!
 

·
Registered
Joined
·
459 Posts
Discussion Starter #12
As far as removing styrofoam from the front goes, Dr. Dave from DDM Works will have to answer that, since he did all of the conversion work.
I am using a Getrag 3.23 positraction differential in my car to make it more driveable on the street with the 500+ HP that my LS3 is making. I am turning 1400 rpm at 65mph and 2000 at 80 mph.
 

·
Registered
Joined
·
164 Posts
Has anyone weighed their car after the LS conversion?
These are from alphajessie, who had the first LS3 conversion done by Mallett that I know of.

Before.


After.
 

·
Super Moderator
Joined
·
16,392 Posts
Actually, with the six speed transmission the numbers I have seen show an improvement in rear weight bias? There is a lengthy thread on this subject from a couple of years ago started by Wade.
 

·
Premium Member
Joined
·
897 Posts
I still have not used 6th gear and have not put a lot of thought into gas mileage. I will say I have seen some toasty temps as I did some city driving with top on and a/c blasting on a 108 degree day -- coolant temps on the DIC peaked at 136.

I have not noticed the trans tunnel being hot but I assume it is. Most of my driving is short top down trips and it is so hot here that I don't think I'd notice the tunnel temp while the top of my head is roasting.

Looking forward to driving in some cooler weather here soon and want to see how that affects operating temps. I know the blower and accessories make a tight package even tighter, but hope the scoop on top and vents on sides are helping. I also have the fan set to come on early and often and am running Water Wetter in the coolant.
 

·
Super Moderator
Joined
·
16,392 Posts
Well we did 8 hour trip to Alburquerque today. I was very concerned about range. The miles to go kept going up for the first hour of the trip. The current version of the tune delivered 27.9 MPG, the DIC was showing 344 miles to go after I filled up on the way. I was very surprised and happy.

Of course the AC does not turn on the pump so there is no cabin cooling, but what the heck.
 

·
Registered
Joined
·
164 Posts
I looks like you guys with the T56 transmission run at a lower RPM and get a lot better mileage then I do with my stock 5 speed Aisin AR-5 transmission.
 
1 - 20 of 39 Posts
Top