Towing with a Turbo Gas engine?
Towing with a Turbo Gas engine?
(OP)
I have never seen a gas engine have good tow ratings, but turbo diesels do well.
Why can't you tow with a turbo gas engine?
If I was to build a 454 Chevy and turbo it, it would be a beast for towing, but why isn't it done or why has it never been done?
My 301 Turbo Trans AM is no recommended to tow with, the Dodge/ChryCo turbo's were limited to 1000 lbs, the Dodge minivan turbo was 1000 lbs, but the 3.0L V6 was 2000-2500 lbs. Same trans. And many other turbo gas engines towing is discouraged.
Why can't you tow with a turbo gas engine?
If I was to build a 454 Chevy and turbo it, it would be a beast for towing, but why isn't it done or why has it never been done?
My 301 Turbo Trans AM is no recommended to tow with, the Dodge/ChryCo turbo's were limited to 1000 lbs, the Dodge minivan turbo was 1000 lbs, but the 3.0L V6 was 2000-2500 lbs. Same trans. And many other turbo gas engines towing is discouraged.





RE: Towing with a Turbo Gas engine?
As I see it, a properly set up SI engine (compression ratio, turbo, spark, cam timing, fuel injection, cooling, etc.)should do just fine. A lot of river rats around here tow with V-8 and V-10 engines. I guess if you can afford a $40+thousand truck and a $60,000 boat, you can handle 8 mpg!
I pulled race car trailers behind Ford, Chevy, and Dodge V-8's for 33 years before I bought my Dodge/Cummins. I don't recall too many major problems (Chevy wheel cyl. in'63, Ford tranny in '72 and Dodge radiator in '90). I will be towing my newest vintage Mini-Cooper behind my 454 powered motor home @ 6.5 mpg. I don't anticipate any problems except fuel cost.
Rod
RE: Towing with a Turbo Gas engine?
I suspect the reason towing with a turbo is bad is piston heat. I melted a piston in my 301 Turbo at 110 mph, heat related, it literally turned to liquid on the top side of it. Maybe just the pistons in a Diesel are tough enough to handle the higher heat of the boosted engine than a gas engine is.
I would think we would see lots of SB350 Turbos out there to replace the 454's to get better mileage and better power with a smaller turbo engine. If my 301 made 345 lb ft torque with those lousy heads, imagine what a EFI Turbo 350 would make. Easily smoking the 454 for about everything.
As for 6.5 mpg, I have been thinking of a 454 Suburban, the only one I have talked to about it said he gets 10-12 mpg no matter how he drives and no matter what he pulls. Sounds close? His was a TBI injected 94 Sub. 95 went Port EFI.
Tom
RE: Towing with a Turbo Gas engine?
Most of the SUV's out here get anywhere from 8 to 15 mpg, but the higher figure is at a lower speed and no one drives at anything less than 70 mph around here. We have an overabundance of incompetantly driven wanna-be trucks on our roads and the usual roll-over-a-week.
My Dodge gets 19 to 21 mpg towing a 3500# trailer @ 55 to 60 mph. My son's later model Dodge gets even better mileage than that. Both have 4.10/1 gears and 235/85R 16 tires. The 454 in the 27 foot Silver Eagle is carburated and 6.5 mpg is about the best it will do with or without a trailer.
Rod
RE: Towing with a Turbo Gas engine?
Cheers
Greg Locock
Cheers
Greg Locock
RE: Towing with a Turbo Gas engine?
Why haven't the car manufacturers ever (yes, I know turbo's are not good for cold emissions, so they are on the way out)make a turbo or supercharged gas engine in a truck? A SB Chevy 350 Turbo/Supercharged will have more power and torque where you need it than a 454 non turbo, and get better mileage, but they don't do it, nor have they ever did it. Why don't you see ANY towing capacities on turbo gas engines?
Thomas Martin
RE: Towing with a Turbo Gas engine?
It seems there are two questions here... SI turbo vs. CI turbo, and SI turbo vs. SI naturally aspirated. Background on the first question is given in the threads, "CI vs SI" thread in this forum, and "why do diesel engines have more torque than gasoline engines" in the automotive engineers forum. As I am sure you are aware, towing large loads means operating on the full load curve for extended periods. Meaning you need torque, torque, torque. These threads explain the problems of detonation limiting SI engine operation at full load. These factors only worsen with turbocharging. CI engines on the other hand are ideally suited for turbocharging to increase torque, and can run there for extended periods. This is one reason why the trucking industry uses diesel engines and not gasoline.
On question #2... I would guess fuel economy is the cause as Rod mentions. Production gasoline cars are not made to run at full load for extended periods of time. At full load, gasoline engines (turbo or not) run rich. The reason being to cool the exhaust and keep from melting the catalyst. Tempertures in the combustion chamber may also be high enough to cause damage without this enrichment, especially with a turbo. In addition, towing means slower speeds with an undersized engine, reducing air flow for cooling, and further increases in coolant and catalyst temperatures. So running rich causes fuel economy to suffer significantly, and turbo charging would only make it worse by needing more enrichment, or other means to provide thermal protection at the cost of fuel economy.
Again, I don't know that these are the reasons, but it seems likely.
RE: Towing with a Turbo Gas engine?
But not under those conditions, it would be much better.
I guess there is tradoff's... Plus the additional heat may be not very tolerable by the engine, requiring internal mods like special high $$ pistons, monster radiators, etc to keep it cool, where the 454 is just plain cheaper....
RE: Towing with a Turbo Gas engine?
Blacksmith
RE: Towing with a Turbo Gas engine?
I can't wait to turbo my lawnmower....
Honda OHC....
But at repeated blasts from 55 mph to 100+ mph, I finally literally melted down a piston. So performance, yes, reliabilty at that performance, not with cast pistons you don't!
Thomas Martin
RE: Towing with a Turbo Gas engine?
We all are nuts when it comes to cars and car related stuff, myself included. When I didn't have much money to play with, I hopped up my Briggs & Stratton lawn mower. Ran great, I left it in Colorado when we moved. I would like to have seen the look on the first person that fired it up!!(Brazed up and reground the cam by hand, DelOrto carb, milled head, tuned exhaust, etc.)
Rod
RE: Towing with a Turbo Gas engine?
Mine would go though tall grass at a very conservative engine speed and not stall, and redline was a very scary rpm! It screamed at the high end! I never have needed more than "3.5" hp in that one....
RE: Towing with a Turbo Gas engine?
Blacksmith
RE: Towing with a Turbo Gas engine?
Admittedly this is a fairly mild turbo installation, but I think that this suggests that the guts of a conventional SI engine CAN take high loads for long durations without a meltdown.
When we used to run engines in the conventional wisdom was that you'd blow them up at the high speed low load conditions, rather than high speed high load.
Cheers
Greg Locock
RE: Towing with a Turbo Gas engine?
Cheers
Greg Locock
RE: Towing with a Turbo Gas engine?
I am shooting for a bit over 150 hp from my 1380cc A+ Mini engine for the Cooper S with one 45 DCOE 9 Webber carb.
Rod
RE: Towing with a Turbo Gas engine?
Blacksmith
RE: Towing with a Turbo Gas engine?
Check out the F-1 BMW and Ferrari engines. Half the size same power range, but at 18,500 rpm !!!!! and for 2 hours flat out . Amazing. I wish I could make it to the US Grand Prix at Indy next year. I worked two F-1 and one CART race at Long Beach, and F-1 is the race to see.
reminiscing----Rod
RE: Towing with a Turbo Gas engine?
Blacksmith.
RE: Towing with a Turbo Gas engine?
Cheers
Greg Locock
RE: Towing with a Turbo Gas engine?
With the advent of Sir Jack Brabham, Colin Chapman, Jim Clark, Graham Hill and the rear engine Coopers and Fords, the die was not only cast for rear engine racers, but for multi speed gear boxes, and the emerging importance of rapid pit stop strategy. Clutches remain, to this day, one of the weak links in the power train. Take a 1000 hp in a 2000 lb. car and slam it from zero to 230 mph a few times while trying to make it last 500 miles and still WIN?
CART, IRL, and F-1 are state of the art open wheel racers, but even with all the expertise and money, things still break, and clutches are right up there near the top of the list.
I was told this little ditty a long time ago, but I still go by it ---"There are 1,000 parts in a racecar, kid. If you checked 99 percent of them, YOU STILL MISSED TEN. " {this is a "TRUISIM" guys, don't panic}
This has gotten WAAAAAAAAY off the original question in this thread, and I apologise. I tend to run on a bit, sorry.
Rod
RE: Towing with a Turbo Gas engine?
We are way off the original thread, but now I remember, a lot of the early Indy drivers moved up from USAC sprint cars, which had no clutch and trans, just an in/out and the rear end gears, Indy wasn't a road course, so why use multiple speeds. I remember one of my early heroes, Dan Gurney came to Indy with a 302 CI Ford, double disc clutch and 4 speed trans. He would light the tires leaving the pits. I guess the point is that usually, a turbo is used on a mass production gas engine to increase all out performance, which may not be the best for towing, while the mass produced turbo diesels tend to emphasize load carrying and towing performance rather than acceleration or top end.
RE: Towing with a Turbo Gas engine?
One day we must meet. My old Lotus Cortina race car is owned by a gentleman in Connecticut and he has invited me to come up and go out to Lime Rock for a test drive someday.
It is my intention that when I have finished my Mini-Cooper to do just that. No date yet, may be a year or more.
Interested?
Rod
RE: Towing with a Turbo Gas engine?
Again, we are on our own chat room. Maybe we should meet, but I'm in VA and don't get to CT too often. Should of had this years ago when I used to get out to Carson (LA) CA about 4 weeks a year while I was teaching EFI and outdrives for the boat company - I had nothing to do and lots of time on the weekends!
Blacksmith
RE: Towing with a Turbo Gas engine?