MRG MotorSports 818S Build

[mikeb75]

'grats on everyone's accomplishments this year. Hope next year is even better!

[Mitch Wright]

Great way to finish off the year.

[Bob_n_Cincy]

'grats on everyone's accomplishments this year. Hope next year is even better!

Great way to finish off the year.

Thanks Mike and Mitch.

[wallace18]

Congrats to both of you!

[Bob_n_Cincy]

We are looking at a front radiator configuration.
We are planning on have a storage / crumple zone box in the front of the car behind the radiator.
Looks like it's going to work. Only testing will tell for sure.
Bob

P1050802.jpg P1050803.jpg P1050805.jpg

[RM1SepEx]

Bob, isn't this the rear radiator car? and don't you need air to flow through that boxed area vs storage?

[Bob_n_Cincy]

Bob, isn't this the rear radiator car? and don't you need air to flow through that boxed area vs storage?

Hi Dan,
Yes this is the rear radiator car.
The plan was for air to be sucked out of the back of the car. Our red neck tunnel test showed at 60-80 mph that turbulent air behind the car was working against us. Our temp starts to creep up over 190f after 30-45 minutes of highway driving.
The storage box would be installed for DD, but removed for autox and track days.
Bob

[RM1SepEx]

I bought a pair of Craig's fener louvers. I'm thinking that between my AAIC and a pair of small radiators on the front sides I can recover that space for real storage. The problem is that every one of those "upgrades" delays getting the car on the road.

[Bob_n_Cincy]

The problem is that every one of those "upgrades" delays getting the car on the road.

I understand that. We have a bunch of little upgrades to do to blue. While trying to get red to go kart stage.
Bob

[Bob_n_Cincy]

Got some nice weather today to work on the 818.
As part of or front radiator mod, we added an engine coolant bleed port. (similar to Wayne's mod)
In my opinion it would be difficult to drill and tap the crossover pipe with it in the car.
Instead we decided to add a temperature sensor housing to the upper radiator hose. The install a 5/16 barbed fitting in the housing.
It's working as expected.



The next thing I want to do is measure the pressure on the upper outlet hose and the pressure coming from the front radiator bleed port.
At Idle 700rpm .
Hose from radiator port was 1ft and upper outlet hose 2ft.

At Idle 1500 rpm. Hose from radiator port was 3ft and upper outlet hose 5ft.

[Hindsight]

Nice idea on the bleed port via coupler.

Why are you testing the hose pressures?

[Bob_n_Cincy]

Why are you testing the hose pressures?

The port on the outlet hose and radiator port both go to a tee at the expansion tank (degas tank).
If the port on the outlet pipe has greater pressure than the port on the radiator. It will block any air in the radiator from making it's way back to the degas tank.
I do not want a system that has to be manually bled of air. I want a system that is self bleeding. Similar to most cars.
Bob

[lance corsi]

Evans waterless coolant. 'nuff said.

[Hindsight]

Thanks Bob, that makes sense. I always figured that even if there was more coming from the output pipe bleeder port vs the radiator port, that there would still be enough to allow some bleeding. I agree about the self-bleeding.... very important to have. Since your test showed more pressure from the upper bleeder port vs the radiator port, does that mean you feel you aren't getting any bleeding action from the radiator?

I asked the question because I'm playing around with this stuff too now due to an overheating issue. I have the same setup you do, in terms of bleeders (though I do have my upper bleeder coming from a fitting I welded onto the upper coolant pipe - but in effect it's the same as what you have). I did, however, block off the heater core lines by capping each one with a block-off cap instead of the FFR provided U-pipe. I can't test during driving due to a bad MAF calibration that i'm trying to work through, but while idling for long periods of time, the radiator fans kick on and the coolant temp just keeps climbing. Are you experiencing an issue like this too or are you more just testing to ensure self-bleeding functionality? My right-side coolant pipe to the radiator is very hot so I know the thermostat must be opening and coolant must be flowing to the radiator, and even with the heater core line blocked off, there should be enough coolant cycling through the turbo, the upper pipe bleeder, and back down the return pipe from the degas tank to hit the thermostat and make it open (the turbo coolant hose, the engine bleeder hose, and the rad bleeder hose are all hot to the touch so coolant must be going through them all). The left side coolant pipe is quite cold though. I'd expect it to be at least warm.

[Tamra]

...... I did, however, block off the heater core lines by capping each one with a block-off cap instead of the FFR provided U-pipe.

I thought the heater core lines had to be looped or the thermostat wouldn't open? Is the cold side also hot (it should be)?

[Hindsight]

Hi Tamra, I thought the same thing but Chad mentioned in a post that Jim Schenk told him FFR was blocking off the heater core pipes instead of looping them on their race cars because that loop made it too easy for the coolant to go that way instead of going through the radiator (path of least resistance). I thought about the same thing you just mentioned, but if you think about it, there are two paths for the coolant to go when the thermostat is closed: 1 - through the heater core loop and 2 - through the turbo, then into the degas tank, then down out of the degas tank. The degas tank return line is connected to the heater core loop return line.

Maybe my thinking on this is flawed though? Oh, to answer your question, the cold side isn't hot... it's cold. Hot side is hot though.

[Tamra]

That means you are not getting flow. Cold side will be uncomfortable to touch if coolant is flowing. It'll be cooler than the hot side but you still won't want your hand on it.

I suspect that the thermostat is not opening. The top side of the engine is just equalizing temperature with the hot side hose.

[Hindsight]

Thanks for the input Tamra; I will try replacing the heater core u-hose and see if that changes anything. The thermostat itself could be the issue. It has set for 2+ years and it wasn't one of the items I replaced during the build-up.

[Bob_n_Cincy]

Evans waterless coolant. 'nuff said.

does that mean you feel you aren't getting any bleeding action from the radiator?
Are you experiencing an issue like this too or are you more just testing to ensure self-bleeding functionality?

Hi Lance,
Even with the waterless coolant, I still need to get the air locks out of the system.

Hindsight,
I have a couple thousand miles and 300 autocross runs on my rear radiator set up with no coolant issues. All my problems were air flow related.

I have a heater core instead of the "U" pipe.

My thinking right now.
I will put the "T" close to the tank so both will bleed into the tank.

I wish I could find some low cost flow indicators to put into the lines.
Something like this:

Bob
'

[Bob_n_Cincy]

Michael and I did 2 autocross fun events (no points) this weekend.
Saturday: Columbus Indiana sports car club. 6 runs each for a total of 12
Sunday: Cincinnati SCCA. Michael 25 runs and I got 15 for a total of 40

So tortured the 818 for 52 runs. It ran like a champ all weekend.
I estimated we used about 8 gallons of gas. About 1/4 the rear tread on my Toyo R888 255/40/17. About 1/8 the front tread on my Toyo R888 235/40/17.

On the 52 runs I only had one spin and Michael had none. He is getting very good at countering steering the instant the tail breaks loose.

My modified suspension is getting very even tread wear with these settings. My suspension has -1 degree of camber gain per inch of up travel. align2.jpg

Here is a video of one of mike's runs.

www.youtube.com/watch?v=igzxJo7TPx0

Bob

[Frank818]

Really cool to see you guys having fun!
I believe you are the ones using the more the car(s), could I be right?

[Jeff Kleiner]

Great to get to see you both again on Saturday! Michael is definitely getting it---you just gotta' teach him to do a better job of dressing for the weather

Jeff

[Bob_n_Cincy]

Great to get to see you both again on Saturday! Michael is definitely getting it---you just gotta' teach him to do a better job of dressing for the weather

Jeff

Jeff,
Good to see you also.
Sunday morning it was in the 30s. He did wear some sweat pants over his shorts while he was chasing cones.
Bob

[Jeff Kleiner]

Jeff,
Good to see you also.
Sunday morning it was in the 30s. He did wear some sweat pants over his shorts while he was chasing cones.
Bob

Our Sunday was even cooler than Saturday---25 when I pulled out of the driveway at 7:30 for the 55 minute drive (wearing 5 layers on top PLUS my helmet!).

Hope to see you for the April 24th event.

Jeff

[Hindsight]

The camber and caster specs are less than I would have imagined for AutoX, though I am NO expert on alignments or AutoX at all.... just going by what I've seen from others. How did you end up at those numbers? Glad it is working for you!

[Bob_n_Cincy]

The camber and caster specs are less than I would have imagined for AutoX, though I am NO expert on alignments or AutoX at all.... just going by what I've seen from others. How did you end up at those numbers? Glad it is working for you!

Hello Hindsight.
Disclaimer, I am an electrical engineer, with limited high performance driving experience. So my settings might be all wrong.


Caster at 2.5 degrees. I didn't want something the was heavy to turn but would return to center on it own.
I tried something this past weekend and it worked. I was on the gas coming out of a corner and the back end kicked out. I loosened my grip on the steering wheel and let it spin on it own. The car self recovered with out going around. So it is enough caster to point the tires the direction the car is going.
With 205 tires the car steered great. With 235 toyo R888 sticky rubber, the car is a little jetty on uneven roads.

Camber at -0.5 degrees.
I change my pick up points on my suspension to give me more camber gain. (about 1 deg per inch of suspension travel)
During a 1g corner I am seeing about 2 degrees of body roll with my spring package. The outside wheel is compressed about 1" so it is at 1.5 negating camber. The inside wheel is extended about 1" so it is at 0.5 positive camber. My goal was to keep the outside tires flat on the ground during hard corners.
I plan to go to -1.0 degrees next alignment.

Bob

[Mitch Wright]

Bob, what does the bumpsteer look like with that much camber gain? I am at 6* caster, with out the body I found the steering still pretty light.
My gut tells me I would still like more static camber than .5*

[Jeff Kleiner]

Bob,
You didn't mention front toe. Zero or a little toe out will give you more initial bite at turn in but comes at the expense of straight ahead stability ("a little jetty"). On the roadsters that see street or mixed street and track use I go for about 3/32" total toe in. You can always run toe in on the street then give a tie rod a twist to toe it out when you get to the track and turn it back the same number of turns to put it back afterwards.

Jeff

[Bob_n_Cincy]

Bob,
You didn't mention front toe. Zero or a little toe out will give you more initial bite at turn in but comes at the expense of straight ahead stability ("a little jetty"). On the roadsters that see street or mixed street and track use I go for about 3/32" total toe in. You can always run toe in on the street then give a tie rod a twist to toe it out when you get to the track and turn it back the same number of turns to put it back afterwards.

Jeff

Jeff,
the settings are front 1/8" out (Negative) and rear 3/16" in (Positive).

Mitch,
I have never measured bump steer.
Michael and I are all signed up to see you on the NCM track Saturday and Sunday.
Bring your helmet to work.
Bob

[Frank818]

Toe-out up front, interesting.
Just learned that at the rear when torque is applied the wheels tend to toe-in. I always thought the axles would then to push backwards, which means toe-out. You made me read on toe, good thing.

[Bob_n_Cincy]

intake air temperature FIX

At our last track day the IAT (intake air temperature) measured at the MAF sensor was 100F while running and got to 120F during a pit stop. This while only 60F ambient.

The ECU reduces engine power if this temperature is over 104F.

My son Michael took charge of fixing this problem.
Our OEM air box was drawing air from the engine compartment.

P1050842s.jpg

Michael used 2 air box covers to modify our air box.

P1050843s.jpg

Then he added a 3" elbow to suck the air fron the side vent.

P1050844s.jpg

The orange elbow is temporary.
I have a different angle on order.
Bob

[STiPWRD]

Bob, have you ran the engine since doing this intake mod? Putting a bend right in front of the MAF (picture 2) will really mess up the reading and cause you to run very rich. I've done this before too (put a 90 degree bend right in front of where the MAF was) and couldn't figure out why the car ran so rich even after removing tons of fuel from the map. The MAF needs to have straight laminar air flow to work properly.

[taco20]

http://flexconverter.com/collections...-harness-02-07

Hey why don't you just move the IAT sensor into the inner cooler with this kit and not worry about what the temp is at the MAF?
I went speed density with mine and used this kit and it works great. If you have a Cobb it has a spot to let it know you are using the Chevy sensor and compensates for the different ready.

[Bob_n_Cincy]

Bob, have you ran the engine since doing this intake mod? Putting a bend right in front of the MAF (picture 2) will really mess up the reading and cause you to run very rich. I've done this before too (put a 90 degree bend right in front of where the MAF was) and couldn't figure out why the car ran so rich even after removing tons of fuel from the map. The MAF needs to have straight laminar air flow to work properly.

Hi STiPWRD,
My MAF and AIT is still between the air filter turbo. We just used an extra housing before the air filter.
Bob

P1050842s.jpg

[Bob_n_Cincy]

http://flexconverter.com/collections...-harness-02-07

Hey why don't you just move the IAT sensor into the inner cooler with this kit and not worry about what the temp is at the MAF?
I went speed density with mine and used this kit and it works great. If you have a Cobb it has a spot to let it know you are using the Chevy sensor and compensates for the different ready.

Hey Taco20,
Before the 818, I new nothing about MAF,AIT, turbo efficiency, speed density, or subarus in general.

I'm still running stock tune open source.
That link you posted, talks like it is no big deal to switch to Speed density.
Bob

[taco20]

Hey Taco20,
Before the 818, I new nothing about MAF,AIT, turbo efficiency, speed density, or subarus in general.

I'm still running stock tune open source.
That link you posted, talks like it is no big deal to switch to Speed density.
Bob

Hey with that setup you really don't have to switch to Speed Density for the sensor to work. It just moves the sensor to a different place. It reads at a lower temp then the Subaru IAT inside the MAF. Mine ready 10 deg cooler then my gauge said.
That is close enough to actual to not effect drive ability unless it is real cold outside. It would keep from showing the heat coming in your air box and tell the computer the temp going into the intake. If you had a Cobb and a good tuner
it would be an easy fix. It is a cheap and easy solution that might be worth a shot.

[UnhipPopano]

The MAF [Mass Air Flow] is in effect telling the ECS [Engine Control system] how much Air/Oxygen is going into the engine. The ECS uses this information to control the fuel rate. Too Lean and the engine will knock and eventually fail. Too rich and the Plugs and Valves will foul up, and lead to engine failure.

The MAF is a Flow transmitter that measures in one spot and correlates this to the entire flow. For the best possible reading the MAF would be mounted in a long tube of the correct diameter. The standard way it is mounted is not optimal, but good enough for the ECS to work with. Mounting an elbow before the MAF will result in a airflow that is not uniform and the MAF signal to no longer be linear. Mounting it in a box will also throw the signal way off and may not be linear.

There is videos on the web that debunk the idea that you can improve the engine's power from taking air directly from the outside of the car. To gain power you need a large scoop that would increase pressure to the intake manifold, but it would also increase the car's air resistance.

[Bob_n_Cincy]

Hey with that setup you really don't have to switch to Speed Density for the sensor to work. It just moves the sensor to a different place. It reads at a lower temp then the Subaru IAT inside the MAF. Mine ready 10 deg cooler then my gauge said.
That is close enough to actual to not effect drive ability unless it is real cold outside. It would keep from showing the heat coming in your air box and tell the computer the temp going into the intake. If you had a Cobb and a good tuner
it would be an easy fix. It is a cheap and easy solution that might be worth a shot.

I didn't want to trick the ECU. I wanted to get rid of the heat coming in the intake.
The configuration I have now is closer to the Subaru original setup.
So I should be good to go.
I will talk to TIC (Turn in Concepts) about switching to Speed density.
Bob

[Bob_n_Cincy]

After we damaged out first transmission, we replaced it with an 2012 MT5. It did not have a VSS sensor mount.
Our second attempt was putting a prox sensor in the rear hub abs hole sensing the lug bolt head. This worked for a month or 2. At our last track day the prox sensor failed. We suspect the brake heat was to hot for the sensor.

This time we modified the front unused CV joint and mounted the prox on the front hub.
Bob & Mike.

[Bob_n_Cincy]

I'm making an 818R roll bar for my 818s.
Can somebody measure the height of the 818R roll bar.
Thanks
Bob

rollbarr.jpg