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Glad I'm not the only one that has dented their IC with that stupid placement of a hood latch. It would be 1000X better if they had simply attached a small locking arm to either side of the hinges -- it's like the chassis design team and the body design team came from different pubs!
lotus stopped using these because over time it warped the hatch.

The hot air from the radiator is an issue. Just stick your hand on the roof on the highway, you'll notice the air there is quite a bit hotter than if you raised your hand into another airstream. Crude thermometer I know but the difference can be felt. I've heard of a splitter added on bottom of front of roofs similar to cup roof along the windshield top edge that supposedly splits the hot air and runs it in a different direction allowing fresh air in the scoop.

Really Really interesting post by the way. :clap:

I am in the camp that thinks that fans is the only way to go. Either roof, the bottle neck is still at the fettle location. Even with fettling, the opening is just... ridiculous. If fans are used, just a theory but I think the non cup roof would be a better combo here.
 

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I have also felt the hot air that comes over the windscreen,it is from the heat of the radiators in the nose,and it is suprisingly hot.
I looked into fans a while ago,and the tiny fans that would fit don't come close to pulling enough air,pushing is not a good idea,either. the only place where fans might help on this car is when it is in traffic,but how much horsepower do you need in traffic? I am still thinking that a scoop on the drivers side "sail" panel(opp side of the fuel filler door)--or a NACA duct ---run into the stock air duct along with the roof might be the answer. It could be replaced with another gas filler door(screwed shut)if desired should the need arise. If you wanted to remove the top,you would still get air into the IC from the top scoop on the clam and the new sail panel air inlet. All of this is just mental masturbation on my part until somebody gets temps and meaningful data. Where is Jim Hall (Chaparral) when we need him?
I ordered 2 small motorcycle fans from SPAL to be mounted push inside the shroud. Just going to use a simple on off switch routed through the fire wall somewhere in the cock pit. I think the pre-IC shroud location provides a good vacuum seal aiding fan efficiency as opposed to fans in the open trying to pull air through. At idle standstill in street, or slow speed hairpins on track, this should help.

I know there are concerns that it would block airflow but in this case and it's just my own guess, since the bottleneck at the rear clam opening is so great, the fans can only help. At speeds, (cup roof) air rams through but is choked at the fettle location, my theory is the fans help pull that stream and push through the IC.

The fans I chose, if mount the way I want them to, on both sides will still leave a small open unobstructed IC space in the middle. Im no pressure engineer but imagine there's some turbulance on eighther side of the shroud, and the fans for the IC (for the exige config) can only help. I'm hoping innovate will come with the IAT parameter update soon so I can log this. I have some thermo couple but don't want to put these direct in the charge stream if dont have to...

On a seperate note, I wonder how much timing changes from the ecu are a result of IAT and how much are result of other parameters like ECT... ?
 

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This may be a little over the top, but has anyone tried a setup whereby a small jet of atomized distilled water is injected into the cooling airstream? Maybe injection could be automated as a function of boost?
A liquid->stream phase change absorbs lots of heat...

BTW- how much HP difference are we dealing with (say between an optimally cooled IC versus no IC at all?)
search RLS aquamist, one of the members here is selling a kit. I've bought one but not hooked up yet.
 

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For those interested, I have the same fans as WildWhl... you can get them at the SPAL clearance center for $38 each...
ah man... i just paid double that, using the same, 5.2" ATV fans.

i just hooked up my innovate system to watch the OBD2 IAT Pid. Before car's started, reading is a bit higher than ambient so appears to be accurate. IAT mid 30C's. Ambient is low 30C's. Infrared temp gun aimed at the IAT from exterior confirm similar temps.

Once warmed up and running, IAT is consistantly around 42C. When full throttle through one gear, it'll quickly rise to 43C+. LOnger durations, 44C. In traffic, idling if the car is hot can get up to mid 40C's.

Not sure how to analyze the info but it's interesting, that at highway speeds, no matter how fast I am going, the IAT doesn't appear to move much. the range is more or less 1-3C and correlation appears to have more to do with throttle rather than speed.

higher speeds which normally = higher flows which = lower IC charge temps are normally reflected by IAT changes that are in line with speed variations/flow unless in cases where the higher speeds do not = higher flow. I guess making a new rear clam/hatch mold for the SC exiges was too expensive to fit in the lotus 2006 budget. When ever i have the roof off, I laugh shake my head at the fettle bottleneck location. Having owned several modified FI cars in the past, I've witnessed the fundamental importance of an efficient IC.

I'm hoping the IAT Pid is accurate (via innovate's OT1 obd2 reader). Have purchased the complete RLS WI IC system and 2 Spal fans outlined above to be installed inside the shroud pushing. Climates in HK are hot and humid so should be a good testing environment. A thermocouple in the roof scoop would also be ideal for the data log but that's still in the works. (If anyone knows how to make a thermocouple for this application that yields accurate readings, please feel free to clue me in. Currently I have the wire(s) run, soldered one inch exposed, stuck in the shroud but temps are about 10C higher than they should otherwise be.)
 

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Anyone out there using a datalogging OBD-II reader? What've you got?
i can. using innovate's ot1, and a laptop. suggestions on log parameters?

planning to do some testing this weekend. impending doom of late nights is upon me...

again if anyone knows how to convert normal thermo wire into an accurate air temp sensor, this would be greatly appreaciated. I already have 1inch exposed wire soldered but temps are 10C higher than they should be.
 

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Thanks for the info... I'm going to take a closer look at the OT-1.

As far as the thermo wire goes... are you using innovate's TC-4 to digitize the thermocouple? I'm not an expert on thermocouples, but I guess there are a few things that could cause inaccuracy. Are you saying that when exposed to ambient conditions the thermocouple is giving readings 10C too high?
yes using the tc4. I ordered a thermocouple sensor kit from innovate and it works perfect so the wrong reading has something to do with the thermo couple wire in question (which was sourced seperately).

yes when exposed to ambient, temps are 10c higher than actual.

as of now, have one end of the wire to the tc4. The other end is about an inch exposed from insulation, twisted and soldered.

My only guess is that the wrong solder was used.
 

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thermocouple...

yea it's K type.

After reading up on the net and looking at pics of air sensors, I think I know why:

1) the thermocouple is sensing surface temps near by even though it's not touching. So the result is a measure non-contact proximity surface area + air.
2) most bought air sensors appear to have some sort of insulation on the probe itself, probably to isolate the probe to air only.

THink I got the 10C difference prior because the probe was near the clam after the car had been run. Ambient was 30s, thermocouple reading was 40s. So that probably explains it.When the car has warmed up and thermocouple in the shroud, temps shoot up to 55-60C. I'm suprised the difference between ambient and inner shroud is so great.

dont know why i didnt notice before but when the car is completely cold, the IAT and the thermocouple probe in question are giving off the exact same reading give or take 1-2C. Using a infrared temp gun clam surface temperature is 30-31C, more or less ambient.

Given 86F (30C)ambient air temp/warmed up car; Does 131F (55C) sound to be reasonable for air temp inside the IC shroud (highway speeds), when corresponding IAT is 109F (43C)?

If I can get reliable readings from the thermocouple, it makes sense to tap the inlet side of the IC pipe and take readings to understand change between inlet and outlet temps on the IC.

I'll try the innovate kit sensor tomorrow, but it's harder to work with, insulated with a yellow plug, looks like a the kind of thermo used on a turkey on thanksgiving. duct tape both to the roof and see what kind of readings come in.
 

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ok cars all set up. the issue with the temp differences had to do with technical problems with the gauges. Laptop temps are accurate. Will do a test tomorrow and log the data.

Close up of thermocouple. these things are really cool.



Attached to scoop entry.



sensor inlet side






IAT and other obd2 parameters via Innovate OT1 and AF ratio via Innovate LC1.
 

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I think this is a full software download from innovate. It's called Logworks. Program doesn't allow an export to excel and I dont want to copy just a section of the graph, there's about 20mins of data.
Support :: Innovate Motorsports

For those interested in data logged; download, install, the above in order to view the data file. PM me your email if interested, the file type is invalid for attachment here.

Look at session 1&3, 2 was an accident. Session 1 is upon engine start to warmed up. Session 3 includes highway driving, ending with semi traffic and parking lot.

TC4_2 is the temp at Cup roof scoop entrance.
TC4_3 is the inlet side temps

All other parameters self explanatory.

Dont pay attention to AFR, my sensor needs to be recalibrated.

I did another run tonight that was accidentally deleted, 2nd gear rolling start redlining thru 4th to 8k rpm to 180km/hr, twice. Inlet temps went up to 80C+ but drop quickly post hard running, outlet temps never crossing 60C mark, dropping slower than inlet IAT did to mean. For the most part IAT temps range in high mid 40Cs to 58Cs when running normally. Will be interesting to see stock IC and RLS+ fans result.

Ambient temps high 20's. TC4_2 hood temps were consitant with this prior to run and raised to high 30C's, and stayed around there regardless whether car was moving or still. Marginally down 1-2C at higher speeds. My guess this has to do with hot air from radiator which heats up surface near roof entrance where thermocouple probe is located. Since it also senses radiant, this is prob why.

When I get the chance, will do the same with a stock IC only. then RLS with Spal fans arrived today... and another data set with fans + RLS IC + heat shield (between engine and IC).

Note: car has large alum rad., low temp thermo RLS IC, WR header/decat, Sard stock airbox highflow filter, airboxsnorkel delete, Ti TWR muffler.



pic of fans inside shroud of stock IC.

 

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Very interested on how the fans workout.

Any chance you wiring guru's could share info on where I might be able to find an RPM signal in the center wiring harness inside the car?

Thanks, Rob.
i think on of the pids is RPM which comes from the ecu... but dont take my word for it...
 

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Bosch MDF and Data Interchange Format (dif.)

oh the innovate software allow log data to be exported to 2 formats; Bosch MDF and Data Interchange Format (dif.), not sure if you can view these.

I can do this if anyone needs.
 

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You can export the data from Logworks as a tab-delimited text file (on a per session basis). It's pretty easy to get it into Excel from there...

BTW, I'm assuming that IAT is the intake air temperature before the supercharger... I guess charge temperature downstream from the intercooler is not available as an OBD-II parameter?


TC4_2 is ambient for air temps flowing thru the IC core. But can also assume air temps pre air intake are similar.

Air Intake -> SC -> IC -> Engine
So
TC4_3 is just before IC
IAT is just after IC which goes straight to intake manifold...
Both post SC temps.
 

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If I'm reading the schematic correctly, IAT is taken from the TMAF sensor, which would put it pre-SC. The temperature signal from the TMAP sensor (post-IC) is not used...
first off, I am just learning by seat of the pants so excuse me if the following is totally off. TMAF= temperature mass air flow?


If what you've pointed out is true:

1) why would TMAF have high correlation with RPM/Load etc? as you say the location is pre - SC.
2) How can this temperature be consistantly higher than that of the post SC/pre IC temps?

Searched around found this link. Pinout 18 TMAF - IAT ground and 31 TMAF - MAF ground. May be there are 2...

http://www.lotustalk.com/forums/f25/forcedfed-dyno-plot-9232/index4.html
 

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I don't have a definitive answer, but I'm leaning towards IAT being pre-SC. Maybe an engine expert can chime in (paging charliex...). Even though there's some correlation, it seems that changes in IAT are related to engine temperature (which is correlated to RPM/Load also) and not charge temperature. I don't see IAT being higher than the post SC/pre IC data in the graph below (from your session3). There's been some discussion of how the throttle body gets heated by some of the emissions gear, which can cause IAT to rise higher than ambient, and be related to engine load.

The pinouts you're referring to are just two pins from the TMAF... and yes, TMAF stands for Temperature/Mass Air Flow sensor (it senses both).
yes the cylinder head gases are routed to the throttle body location. But these temps must be in the 100C's. (more reason to install a vent to atmosphere oil catch tank)

The MAF is before the TB, on the airbox, so is that to say the TMAF is not located behind the throttle body then? If not, then this temp sensor should be getting hit with only ambient air. I'd think the ecu would want to take IAT temp post SC because this is the charge right before combustion, so seems counterintuitive. hmmm...

on your graph, whats the yellow temp? if it's downstream and it's not the "TMAP IAT" location on the exit side of IC, did you put a probe here?

nice job on plotting the graph, thanks for doing that.

Oh... note checked multiple times with an infrared gun pointed at IAT location (at idle), and it matches the IAT reading. But this could just be a coincidence.
 

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Yes, and I think some of that heat soaks the area around the throttle body, perhaps even the airbox (making it an interheater, I guess).
but the MAF is really really "far" away from the TB and the fact between it is the rubber inlet and abs plastic on the box that act like heat gaskets. just find it hard to believe air rushing downstream would still yield such high heat soak. Also when i was monitoring the IAT, the temps moved really quick up and down, quicker than I guess heatsoak can. The TC4_3 IC inlet temps behaved more like a heatsoaked location would.


I would have thought that it would be useful to measure the temp of the charge after the IC too. :shrug: Maybe it has something to do with the evolution of the ECU; the N/A version of the car only needs the temp and flow from the TMAF at the airbox.
but that's cos that's the intake charge temp that goes direct to the intake manifold... as opposed to SC. I mean on an NA, there'd be no other place to put it.

if you are indeed correct about this, i dont mind tapping the other stock tube and getting data there. I have an extra yellow sensor probe as well as thermo wire twist probe.

The yellow temp is cooling air from the roof duct after it's passed through the IC. The sensor I used to measure cooling air flow through the IC has a thermocouple and pressure sensor too, so I was able to take all that data at the same time.
Just to add a little support to this... here's the graph of downstream cooling air vs. speed that I logged... note that there are 10-15 degreeF (6-8 degreeC) increases in the cooling air during high load periods... I'd expect to see some of that in the IAT if it was post IC..
.
OIC what you mean, right increeses in speed followed by heat transfered air... that makes sense. But this does coincide with the IAT data under the theory that it is post SC. JUst might not be able to see this in the graph made off the innovate data because 1) changes are almost instant. check the graph using the software, follow the time line towards the end where the cars running a bit harder, and watch the IAT and Load, there's definite correlation. 2) Keep in mind i was cruising to work for this session and not driving as one would in a spirited fashion. the session where I took 2 hard consequetive pulls was accidentally deleted, but reflected the correlation better because the fluctuation in IAT was much more volatile. There's a typhoon warning for tomorrow so might not get a chance to log some hard pulls but will do so and email to you asap.

Yes, at idle the SC is bypassed, so the air coming in from the airbox is not compressed, and should be roughly the same temp post IC.
right which also why it would rise inline with throttle when compressed...

you might be right, but hope not...
 

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It's the schematic that has me convinced that the IAT shown as an OBD-II parameter is from the TMAF... the TMAF is labeled IAT in the schematic, and there's a large note saying that the temperature signal from the TMAP is not used.
:coolnana: let's swap the wires and see what happens :p no seriously shooting in the dark here, but assuming post SC is the optimal "correct" IAT position, perhaps lotus thought the engine could run faster and handle running on the "misinformation", and because they knew the IC couldn't cool charges enough anyways, so they left pre SC (knowing if they hadn't the SC cars would be dog slow). If so, any cars planning on boosting up, should seriously consider compensating for this eitehr via relocation or ecu map. Or... figure out a way to cool the charge down nearer to TMAF temps.

even though I am sure there's more inputs that determine spark advance (one of pids and logged), it would be interesting to establish thecorrelation between spark advance, fuel trims versus the IAT data. This would help us understand in relation to other inputs, which is most important. For example, I suspect ECT is pretty important but doesn't appear much attention is spent to control this variable. wheres the statistic/regression analysis software when you need it... time to dig through those econometrics class materials...
 
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