good intake manifold temperatures?

[JustinL]

Does anyone know how hot the intake air temps have to get before I need to worry about turning down the boost? I'd like to set my intake temperature warning, but I have no idea what to set it at.

[soxnail]

I would think that the car will just run rich and loose power but no damage should occur. So if you are monitoring afm then you should be ok.
Sox

[JustinL]

I run a MAP based system, so manifold air temperature is part of the equation. I'm just curious about how hot is too hot. They say that a turbo just starts blowing hot air once it's out of its efficiency range... wondering what that translates to in terms of temperature.

[soxnail]

I would think that the compression ratio of the turbo (inlet/outlet) would be the determining factor of how hot the charge gets. If the turbo is out of its efficiency range then it will just put out less charge (compared to it rotational speed) but the temp of it should be dependent on how close you squish the air molecules and as such the energy content is in a smaller space (as energy cannot be created or destroyed, first law of thermodynamics) the whole thing gets hotter.
BTW do you fly? if so what equipment ? if you don't mind my asking.
Sox

[JustinL]

I think I need to do some more reading about turbo efficiencies. From what I've learned though is that as you compress the intake more, you get more heat. With more heat and more pressure, the risk of detonation goes up and up and up. I'm trying to put a number on how hot things can safely get in the intake before I need to slow down or make adjustments.

I think you are referring to my Imperial Pilot line? Heheh I don't fly, but my helmet looks like something out of starwars.


I have a black visor on mine

[soxnail]

You are correct on the detonation and charge heat bit...but your knock sensor/control will take care of it (unless you have bypassed all of it).
May the force be with you
Sox

[nize]

JustinL; does your megasquirt setup have knock detection? can it pull timing and boost when knock is detected? if so, you shouldn't have to worry so much about turning boost down with increased intake temps as that should become self-evident when it occurs.

i've actually found that i have to increase boost pressure as intake temps rise in order to compensate for the less-dense air coming in.

[JustinL]

Nize, I'm still using the DME and KLR for my ignition. So I'm hoping the factory knock control is still working well.

As for the temps, I'm just worried that I'm running my little K26/8 right to the edge of its efficiency, but I've got no idea how to quantify it.

[nize]

okay i'm curious, do you have a writeup of your megasquirt system that uses the stock dme+klr? i'd like to know how that's done.

what boost level are you running and how are you controlling it? which w/g, controller, etc.

[JustinL]

http://www.msruns.com/viewtopic.php?t=18902

I'm running about 18psi (220kpa) MAP. I use a MBC in dual port mode with a tial 38mm. I've been thinking about trying to make megasquirt control a solenoid for boost, but I'm not sure how to make a failsafe so if something goes wrong it doesn't overboost.

[nize]

ah wow, that's pretty cool. so the megasquirt is only controlling fuel and not spark? why not go with a full megasquirt system? i have heard/read it can be set up to handle ignition/boost cut on knock.

at 18psi, the stock k26/8 is not running out and you don't really need to worry about high intake temps unless you live in some super hot climates or something. i've had it up to 22psi with my standalone ems with no problems.

[JustinL]

When I put it together last year, MS couldn't do a dual wheel decoder and couldn't handle the number of teeth on the flywheel so a trigger wheel would need to be welded on. I also like keeping the klr because the factory set up all the noise filtering which can't really be done without a lab setup. I'm going to be doing a microsquirt conversion to my n/a when it becomes available with full spark control. I think I can make a wire-in/pnp stand alone solution for 500$. I'll be posting the details and progress as it becomes available.

[nize]

the ms not being able to handle the stock flywheel timing is something that seems to keep coming up. do you know the specifics of this? why can't it handle the stock flywheel teeth?

the klr noise filtering is a good point. you could go with a full ms and use the j&s safeguard for knock protection though.

[nize]

double post

[JustinL]

Originally posted by nize
the ms not being able to handle the stock flywheel timing is something that seems to keep coming up. do you know the specifics of this? why can't it handle the stock flywheel teeth?

To re-use the stock sensors in our cars, we need an ecu with 2 VR circuits because there are no missing teeth on the flywheel. Instead we have the reference sensor. The latest beta of MS2 can handle the 2 sensors. Also for a while with the older codes, the processor couldn't keep up with the frequency of teeth that come from a 130 tooth flywheel at 6500 RPM (14 000 teeth per second). Both of these have been solved with the newer codes, and I'm just waiting for microsquirt to be released and I'll try implementing it.

[nize]

ah, that makes sense. thanks for the explanation. now what's microsquirt? if it's the new megasquirt, why not call it megasquirt5 or whatever?

[gt37vgt]

i took temps in the post intercooler pipe years ago and got a max temp of 33 C at 20 psi

[nize]

Originally Posted by gt37vgt

i took temps in the post intercooler pipe years ago and got a max temp of 33 C at 20 psi

what was the outside air temp when you got this reading? i doubt you'd get 33c intercooler temp when outside air temp is at 80c, as an example.

[soxnail]

Nize where are you living 80c = 176f
Sox

[nize]

i'm just using an example.