S3E2 Fuel and aerodynamic mods ....We do some experiments to try and get the Saturn to go faster. 

the fact the coolant isn't very warm on this engine stock is not necessarily a problem, since kubota likely designed it to operate under load as a stationary engine for very long periods of time, while being as thermodynamically efficient as possible, hence the cold exhaust manifold. by blocking off almost all the airflow to the engine bay with the airomods, the engine is likely now heat-soaking under heavy load, leading to your perceived power loss. additionally, without an oil cooler, the higher than stock RPM is probably getting the oil nice and toasty-you should probably be monitoring the temperature of that too.

Alright, I'll pitch in now. I own an 82 Isuzu I-Mark Diesel. .50 drag coefficient. From the factory, it is equipped with a 51 horsepower, 72 lb-ft 1.8L engine. On the tire size, from the factory, it was equipped with 155/70R13s. Those are difficult to come by where I am, so I run 175s. I also run my tires at 40 PSI. I've been able to pull 62 MPG out of it. 0-60 takes 20 seconds. Fastest I've ever had that car on a test track was 94 MPH. Not kidding. Anyway, just figured I'd toss you that information to give you a base for what was commercially available.

I wonder what effect covering the rear wheel wells like with the insight would have

It's the boot spoiler! Removing that cost you 3 seconds! :-) Everyone know's they make you go faster! I reckon adding a couple of stripes will knock another couple of seconds off!

Possibly fuel supply shortage? A turbo should lower EGT with the help of an intercooler. Looks good so far Jimbo keep it going 🙂

Robot Cantina: Posts new D722 video Me: Searching Craigslist/Marketplace for a junker to do the same.....

Try putting the spoiler back on. Strange as it sounds it might actually cut drag in your case. IF The airflow stays attached going over the rear of the car that can increase the air pressure acting on the rear window which has the effect of pushing you forward slightly or at least pulling you backward less intensely. If you have a pitot tube and/or a magnahelic gauge laying around that you can measure air pressures you can do an a/b test on that or if not you could do tuft testing with some yarn to at least observe the airflow to see if you have a separation bubble

You should push the speed in 4th speed higher because it seems that the gearing makes the 5th very "long" for economy. When switching from 4th to 5th you go down to 2400rpm!

I'd bet the spoiler did more for aero than you may think. I know all late model cars and trucks have a hangover lip off the truck or tailgate to smooth Eddy currents at the rear of the vehicle. That spoiler might have done just that.

Looking forward to the turbo test! In theory, you’ll be wide open throttle less if you boost it, so your EGT’s shouldn’t be too insane. I’d get a gauge for oil temps just in case, and run an oil cooler with a thermostat.

If you want to gain 30% more power do the LPG (propane-butane) injection to the air intake. If you never heard of this, search for LPG-Diesel. Actually I have this system mounted in my 2.5 Audi A6 C5 and it is working great. Before I installed proper system, I was experimenting by just putting hose from camp gas tank into air intake,.You can try this for beginning :) (this is short term solution, because without heating system for gas, nozzle will froze after few minutes).

Excellent progress Jimbo! Do I hear a bad wheel bearing? That is additional mechanical drag if so. Does the Saturn trans use atf or gear oil? If the latter, then a swap to GM Synchromesh oil will reduce drag further. Look forward to the turbo installation!

I'm afraid you might have blocked off air intake into engine, so it's possible that after some time of max throttle engine is starved of (cold) air, so maybe installing a cold air intake would work out, and since you have that area on bumper to cut, you don't have to ruin bonnet. Should slightly improve performance on high speed doubling as an inertia supercharger (air resistance in front push more air into engine) Cheers, that's a good project and video, Thanks!

Smokey yunick ran airplane tires on his high mpg car "hot vapor fiero" he built. Not sure why haven't researched. I saw it at the don garlits museum here in florida.

a small turbo with a few pounds of boost would solve every problem with speed, and make it so the car doesnt need to have crazy aero mods. Plus, turbos for diesels increase overall efficiency and can easily lead to more MPGs Maybe a k03 turbo from an older audi / volkswagen turbo engine would do well... The inducer size on those is like 30mm so not too big for the baby sized engine

This sort of reminds when I was 9 or 10 years old , riding a Kubota on a rice/padi field in my village.... Never in a watever lifetime a YT content gonna kicked my memory into reverse 😁

Needs a air dog 165gpm lift pump,125hp injectors and a 63mm turbo and it will be golden 🤣

stop messing around and bolt on the turbo, I have this same engine and want to know what its capable of, lol. todays video answered a lot of questions I've had about the fuel enrichment screw, thanks.

You don't need a wind tunnel, I'm sure a CFD company or a CFD engineer would be happy to help you model the car and run the *simulations*

man this channel is so charming. Just curious, are you getting weird harmonics with that engine or smaller wheels/tires? i hear some odd noise on your acceleration test.

Try adding water meth when you go about installing the turbo. It will help drop charge temperatures and will also add more fuel into the system. Also that aero is probably a bad idea since you’re going to want that area and air flow for a intercooler. Like another viewer commented rig up a cool air intake, your power loss is most likely due to the engine breathing hot air. It’s not about how much boost you can cram into an engine but how much air density you can feed it.

Seeing the engineering on all other videos I have no doubt you could add oil squirters to this engine. Tap into oil galley and just add them to stand alone rail inside block under rotating assembly. Honestly that would be simple compared to the other wizardry you have already done.

To verify if the aero-mods are improvements or not, you could use cotton/textile strings and a camera to see flow separation, turbolence, etc. A Pitot tube or Magnehelic gauge are a bit more expensive but obviously more accurate. Would be cool to see the data of lift and drag before and after mods

Fun stuff as always. I'm excited for the turbo!

it’s good to see another 18v makita impact driver up to no good on cars, at least i’m not the only one

ALSO, DON'T FORGET, the weight difference between each wheel, space saver v normal.. SO I AM surprised, you had slower acceleration...🤔 I have a 2007 Fiat Grande Punto 1.2 8v (ahem 'Estimated 65BHP' factory), and I know someone who has the exact same car that I have driven a coupla times. Mine, though had been fitted with large aftermarket 205/40/17s by previous owner, his - standard (alloy) 185/65/15... And MAN.. What a difference! Acceleration? - Hahaha, Fuel Economy? - "Here, just go ahead and burn my wallet!" Hahaha... It HAS made me think 🤔, 'IF' I could get a bog standard steel wheel with 205/45/17 tyre say, and compared the weight with one of my wheel & tyre.. COULD I get a lighter wheel & tyre AND STILL have the grip but better acceleration/economy, as, I'm sure, it must be, that a lot of the times the cheap alloys are heavier than and equivalent steel wheel and tyre setup..... 🤔🤔🤔 😎🇬🇧

Aero engineer by education here, a couple of tips to consider: 1. The spoiler does actually help with aerodynamics. You probably don't need to put the big spoiler back on, but you can get the little plastic stick on spoilers, or even just cardboard/plastic board plus tape to help the air at the back to separate from the trunk. You just want the air to ramp up a little bit. If the air can "jump off" the spoiler ramp a bit, then it can rejoin the airflow easier and reduce drag. 2. Another cheap thing you can do is try adding vortex generators to the back of the roof, to help the airflow stick to the back window as it flows down. Something like you see on Subaru WRX's. This will also help guide the air into the spoiler. If you want to crank the hillbilly aerodynamics up to eleven, you can add a full undertray and boat tail. The channel "think flight" has a small series about this for a better visual of what I mean.

Cool project you got going. Volkswagen in Europe has a model titled Lupo, dont know if available in US? This does easily 2,9liters/100km. It is a 3 cyl turbocharged diesel. Some very serious attempts to lighten just about everything. Even the transmission goes to such extent as hollowing out shafts....Note that when you closed the air inlet, you may in fact have increased the frontal area...

You need one of those little English muffin sized turbos for that engine now

I thought I was having another stroke for a moment. SUSCRIBIRSE!! 🤣

Did you hook up the brake power booster vaccum line?

The exhaust on my Cub Cadet with a D600 Kubota gets very hot. It has a stamped metal safety guard. Under heavy load it blows black smoke, 54" snow blade, chains and tractor tires. I use it to plow my drive way over on Fox road by MIchigan ave near your old stomping grounds. In cold weather the tractor runs very cool, the only time I see the temp gauge move is during summer. There were Cub Cadets that came with those diesels. The garden tractor pullers use a turbo from a European smart car, its 3 cylinder, and has the turbo built in to the manifold, you just need an adapter plate. The Military also had d722T on their generators.

Why not remove a shim from the the injection pump to advance the timing. Might not be ideal once it is turbo though.

if you do decide to run the ubiquitous RHB31/vz21... theres a billet compressor wheel upgrade available. i really would like to see a comparison between stock and billet on these things

I wonder if it’s a intake air temp issue that caused a reduction in power.

I've seen a video (no site details because yt keeps deleting my comment) of kubota d902 (so almost the same) installed in a snowmobile and claimed to be able to make 80hp (but kept at 65-75hp). I think your engine is going to be just fine. :)

Fender skirts? Increased tire pressure? Air scoop enclosed directly to intake? Front campaign sign mod increases downforce, try moving top forward and bottom rearward, so it looks like an arrow shape from the side (reduces downforce, reduces drag)? Lower oil viscosity,? Water injection? Continued success! Thanks for the video!

The rear wing, surprisingly, helps with aerodynamic drag. See SuperFastMatt's latest video.

Hey Jimbo, That was a fun video. You can fit a pressure guage to your fuel supply point at the pump, make sure you're not dropping fuel pressure at wide open throttle. That engine should be good for 1 Bar boost, it has a tough sub assembly. You can also safely go to 650 on the egt, but you may want to either intercool the boost or add water/meth injection...keep going !

Hey, I had a diesel swapped SL2 a few years ago. Aero mods on mine were blocking the front ducting with plastic removing the side view mirrors and having mirrors mounted inside the doors that could see outside. They were basically a convex mirror. Worked well. And on the sedan at least the front lights were inset on the body. The lights were mounted on stand offs to ouch them out to be more level with the hood and front bumper. And finally the wheel covers were like the flat ones you see people running at bonneville. Car got about 90-100mpg when driven nicely. And even driven hard it was capable of 50-60mpg.

The majority of small diesel equipment engines that are turbocharged are running low boost to help with widening the torque bulge and keep revs consistent when the load varies. Typically, manifold pressure is 4-6 psi so an intercooler is not really needed, nor are piston oil sprayers.....however, the majority of turbo Kubota's do utilize a water/oil cooler under the oil filter. An air/oil cooler would probably be easier to fabricate and would greatly help with engine/turbo longevity, especially when holding full throttle for long periods in top gear.

I took the spoiler off of mine because I liked the clean look without it better but it actually hurt my gas mileage a bit. More modern cars will have a little lip on the back of the trunk lid that would take the place of this spoiler for you. Manufacturers claim 1-3% increase in fuel efficiency from that, so it has to reduce drag significantly.

i don't know about your state but my state if it came with seat belts,right mirror and CHMBL it stays i have been pulled over by uneducated in classic cars cops one time for not having CHMBL on my 77 impala and once in my 61 caddy series 62 for no seat belts and in my 48 chevy fleetmaster for no mirrors no belts no reverse lights even the parking enforcement when i lived in the city tried to go after my 73 cheyenne 4dr camper special c30 454 with the extended box for being over 21' but my state is classic friendly so none of it stuck the only one they ever got me on was in my 86 regal for going thru a intersection with wheels of the ground or something like that certain ares don't care for hydraulic lowriders.

skinnier wheels will indeed have less rolling resistance and provide less air resistance. You can also max out the pressures to whatever the sidewall allows. You can also try to cover the rear wheel wells.

Id really like to know if you could make it a electric diesel hybrid. Either run like 5. for example 120amp alternators or hook it to a genset, have a simple capacitor bank (instead of stupid heavy batteries,) and have two elec drive motors. that are fed by the capacitor bank. ie no mechanical drive train. That way your engine can run in its sweet spot rpm wise and you potentially better mpg mph and 0-60

Very interesting stuff!!! Keep it coming!!

The lighter the better.. mabie remove the hubcaps, the heavy interior bits, the trunk lining and spare, any extra seats etc. Mabie it was the wind block in the front of the grill, who knows🤷‍♂️

Such a fun project to watch! We can't see what the exhaust is doing, but if you're giving it more fuel then it may also not be buring it completely. Maybe consider adding a propane injection when you get the turbo on? Thanks for sharing!

The extra air from boost will help cool the exhaust some up to a point as it will lean the mixture back out to normal. The mixture now is rich , and should be running cooler but its diesel and I don't know enough about the fuel system. Normal exhaust operating ranges can vary and be quite high on some engines. This is at full load in 5th right now . Its laboring. Boost will make a huge difference. 6 to 10 lbs. Would be a great improvement

Id recommend advancing the pump timing to make some power

The transfer pump you are using is all the evidence you need of air bubbles in the fuel. Magnetic piston fuel pumps of that type are notorious for causing cavitation bubbles in fuel lines, especially with oil fuels like diesel. It’s a well known phenomenon in the self-installed diesel air heater community. Try mounting your pump on about a 25-45 degree angle with the outlet side up and the inlet side down. This is the first piece of advice given to anyone dealing with cavitation bubbles in a heater. I sincerely hope this helps. Thanks for reading my comment and thanks for all the great content. I have been watching since the insight first got a predator.

Very Nice! Fun times had by all!

I half-expected you to try the flat wheel covers like they use on tractor-trailers for drag reduction. And.....why don't you want to deal with the police?

Having a 999cc turbo 3 cylinder gasser in my daily driver, I find this series quite intriguing. My brother has the same car I do but with the naturally aspirated 4 cylinder. We both have five speeds and the difference is very noticeable. His transmission has much shorter gearing and close ratios. Mine has much taller gears and significantly wider ratios which I assume is to give my turbo a chance to spool up and do something. I'm curious if the close ratio transmission is going to be a problem during acceleration once the little Kubota gets the Turbota.

Would the car go faster if you took the black covers off the bumper with the fuel adjustments? Sometimes blocking airflow like that makes a difference in aerodynamics too, and not in a good way.

I bet removing the rear seat and front passengers' seat would be help for weight reduction. The best car to put the little diesel in would have been a late 1980's GEO Metro, they only weight 1650 pounds. But we use what we have for experiments. I like how you explain things as you go, it helps us who don't understand everything, understand. Thanks from Michigan.

I can tell you from experience this engine in a G1900 tractor the exhaust gets hot. Very, very hot lol. It also runs a little faster than yours did before your governor adjustment.

Maybe your fuel is getting hotter and hot fuel is less dense. With less fuel in the tank and longer testing times it should get worse.

Some of these have already been said by others, but: Power loss might be due to warmer intake air temps from closing off the grille. (Also, worse aero can notably hurt near-top-speed acceleration.) Maybe could run a hose from the rectangle hole in the airdam to the engine intake? Removing that spoiler might make aero worse (that type of spoiler is probably catching airflow coming off the roof and helping it separate from the car cleanly). Blocking unnecessary air from going into the engine bay with that airdam is good, but a sharp 90-degree transition at the bottom of that airdam is not good for aero. An easy way to make that a nice smooth curve is to get a length of foam pipe insulation two or three inches in diameter; slice it in half lengthwise so it's a semicircle in shape, then glue it round side out to the airdam so the bottom edge of it lines up with the bottom edge of the airdam. So that from the side (with the car aiming to the right), a cross section would look like a lowercase b.

Just get smart car tires on the donuts

The pyrometer (exhaust gas temperature), is the best way to know just how a diesel engine is performing. you can figure as the exhaust temperature rises water temperature will rise along with it. there is some amount of over fueling that is acceptable. but if your smelling raw unburnt fuel then it's over fueling too much. a small puff of black smoke when shifting gears is acceptable. as long as that is the only smoke that is detected. there is a huge difference between turbo charged and naturally aspirated engines. and you want to have an intercooler with the turbo. but you will really have to keep an eye on the pyrometer. if the temperature rises too possibly nine hundred degrees for that engine. back out of the throttle and the will drop. and on both turbo charged and naturally aspirated engines you will want make sure the exhaust system is large enough diameter. it's important that diesels have free flowing exhaust. and don't ever shut off a turbo charged diesel with the pyrometer over six hundred degrees. I know this from many years of being an OTR truck driver and have ran a lot of turned up diesels.

I'm impressed with those numbers. Good as a VW TDI or little Saab TDI. Obviously, the recirculation of the exhaust gas will balance the increased KW Joules nicely. ✌️♥️👍👍 Maybe the drag at the rear should be red yarn tested with three or four 1 meter lengths across the trunk lid. In practice the yarn will likely not fly straight away but instead suck back into the low pressure drag ares created by removing the vortices extending wing. Good for a guy riding your tail on motorcycle but not for acceleration and fuel savings.

Put the wing back on. Propeller heads at GM designed it for fuel economy. Also consider rear fender skirts (like your Honda). Make them out of that sign board stuff you put on the front

The engine is likely heat soaking which would explain the power loss. If you put a hole in the aero mod for the intake air you will get way better power and lower egts. This bit will be very important for turbo charging as without the piston oilers and perhaps a oil cooler, you are going to want the air going in as cold as possible. Remember colder air going in give better power and fuel economy

Adding boost to a diesel is not the problem.....adding too much timing is the real problem. As long as the egts are in range, you'll be good. And put in some good oil ( Schaeffers or Lubrication Engineers )

19:15 the aero mods made it WORSE. a flat panels on the front that you made offers MORE resistance than a hole

I have a 2000 Honda insight. I have four spare wheels on my car. They are supposed to be at 60 psi loss mileage at that psi. Air them up to 90 psi and you get a lot better mileage.

Dope ass channel keep her coming!

Also you can try replacing hub wheel bearing(s) i can hear that distinctive sound and they cause drag, i dont know if it's only left front wheel or both front wheel bearings.

Come on turbo, we added a oil cooler with our mod on our old cummins, that was a good move. Might want to watch that oil temp. Have a wonderful week. God Bless

Seems to me that going by the speedometer on the car can't be right. The number is higher because the tire is smaller, and smaller wheels cover less ground per turn. See where I'm going with this.... Good job on your videos

Looking forward to the turbo test. Diesels LOVE boost

Would be interested to know if you could tease 31hp out of that 722, struggling to find a super compact diesel engine that size to generate that power

One thing that can help is lighter wheels. I’m sure those little steelies are pretty light but when it comes to rolling only a few pounds means a lot more. I’m sure you knew that though just wanna see some nice rims on the beast performance wise that this is

12:10 Cold exhaust at idle. This is typical for a diesel. The excess air running through the cylinders keeps the engine cool. This is why idling a diesel for long periods is a bad thing as it leads to " Wet Stacking" / lots of carbon. Some gas engines during a cooling system failure shut down alternating injectors to limp home the car.

Mount motorcycle tires on the spare wheels! (idk if motorcycle tires are better durability than "temp spare tires", because they don't last much longer on a vehicle that weighs ~1/4 as much, with twice the tires)

You should have left the car in its natural state. The only aerodynamic aid you needed was to install the hood. You should always test for real world circumstances. Acceleration is never going to be a show stopper. At this stage i will say you are splitting hair!

Can't wait for a turbo

Hey...what if you use narrower, tall tires.. taller then the spare tire, but narrower then the stock tires? Also what if you used a smaller lighter radiator, like a heater core modified with a inline filler cap? Also could you put a rivet losely in to the thermostat flow by vent hole to help with the engine temperature? Its just an idea..

Love your videos!

The rear spoiler might actually reduce airo drag, please try to re install it and see how the top speed change. The spoiler might work in a way that it reduce the low pressure area on the back window and the slope, now a part of that is lift and a part of that is drag because of the slope. The spoiler will in a control mater reduce this low pressure by resisting a bit the airflow and separating it from bending down to the back of the trunk. You make too many modifications at the same time, how can you say what works and does what, you make one mod and gain 10 points, and an other mod that you lose 9 points, the outcome is 1 point.

You should have left the dirt, it added a low pressure zone causing the air to help push the car forward! Lol I can't wait to see more.

Donuts in the back, all aired up to 45 psi should give a couple mph. A little turbski should unlock 75 mph at least.

removing the rear spoiler is actually counterproductive, you want turbulent air at the back of the car, and very smooth air at the front.

This would be interesting to run on the salt flats, probably do very well in a power/weight calculated division

That intake using hot air from engine bay reducing power and short inlet reducing low end torque...

The spoiler helps with drag. It elevates the trunk and helps the flow to reattach. If you want to reduce drag further, look into making sharp separation edges on it and on the bumper.

If you blow that Kubota, I've an extra Kubota V-2203 fresh on stands

neat

Blocking off the airflow at the front might now mean the underhood air is now entering mostly through the radiator. So this air will now be warmer than before. If the engine inlet air is drawing from this source then power will definitely be down.

Thanks for another interesting episode! That little Kubota is gonna go places :-) Wondering what new thrills and chills (or pitfalls) the turbo is going to bring. We'll see next Sunday :-)

Can confirm a 26hp Kubota tractor engine has cool exhaust at idle, cooler yet in winter.

Sweet!!

Hmm, seems you have really bad wheel bearing noise...might help to fix that.

good to see you’re doing better jimbo!! keep up the good work. highlight of my weekends

Never seen a 2nd gen saturn with no right mirror. I know the 1st gen sedans had the right mirror as optional. I used to sell right mirror delete plates found on cars at salvage yards.

That little diesel sounds lovely, though I've always like the noise that 3 cylinder engines make. The fuel delivery on a turbo diesel should be matched to boost pressure, otherwise you'll still get smoke off boost. If you were keen I suppose you could use a servo or stepper to adjust the rack stop automatically if that is a problem.

The idea to remove the spoiler is terrible because it creates a sharp seperation edge that helps alot in reducing turbulences in the Air. The fact that it sticks out a Bit in the front doesn't seem to be important because this area is most likely to be a low pressure area. The Saturn engineers aren't mindless after all.

I think you should use the insight wheels on the saturn to test if the lighter weight, combined with the wheel design could reduce drag and make it go faster! I just looked, and both sets of wheels should have a 4x100 bolt pattern with an offset range around 45. Who knows, maybe even a cardboard and duct tape mock up panel to copy the insight (rear wheel well panel) would help too!

Weight... shave weight... thats going to have a greater effect on accelerating... the aero will help with efficiency... Power to weight ratio.