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Non intercooler setup

Discussion in 'Turbo Tech Questions' started by Novi347, Jun 20, 2024.

  1. Novi347

    Joined:
    May 29, 2024
    After over 24yrs of supercharging, I'm making a switch to a Turbo combination. Just ordered an FIS GTRS47696 for my 363 build. Question is for individuals who use meth injection solely instead of intercooling? I've had great success doing it on my Blown application in the AZ summer. At full boost of 20lbs my IATs were steadily in the 90 deg range. What type of IATs do turbos reach when street driving? Thanks in advance!
     
  2. B E N

    Joined:
    Nov 22, 2016
    EFI or carburetor? How much boost?

    If the turbo isn't undersized it could be fine. I think an intercooler is always a good idea, fox kits are inexpensive.
     
  3. Punk.Kaos

    Joined:
    Sep 22, 2023
    I'm running meth injection on a twin turbo big block non-intercooled. At 20PSI I can go as high as 130F on an 80+ degree day. Meth kicks in at 8PSI.
     
  4. Novi347

    Joined:
    May 29, 2024
    What's Temps while street driving
     
  5. Novi347

    Joined:
    May 29, 2024
    It's fuel injected
     
  6. Punk.Kaos

    Joined:
    Sep 22, 2023
    Usually 20 or so over ambient, depending on the weather and not sitting in traffic obviously.
     
  7. Novi347

    Joined:
    May 29, 2024
    So it's definitely streetable! Thank you
     
  8. Punk.Kaos

    Joined:
    Sep 22, 2023
    Ohh yeah, I drive it around regularly without any problems. Out of boost its totally fine, and while the IATs do come up in boost the meth has kept them to reasonable levels.
     
  9. Forcefed86

    Joined:
    Nov 24, 2005
    Pretty wide misconception here with meth injection. The temps reported by an IAT sensor are total horse $hit. Its a stationary probe that is having heat constantly pulled from it over a long period of time. It is in no way an accurate representation of your charge temps.

    Cruising charge temps won't hurt ya at all as you don't make any boost cruising.
     
  10. saltfever

    Joined:
    Nov 15, 2007
    Huh? Then what is the correct way to measure it?
     
  11. Briansshop

    Joined:
    Dec 12, 2006
    Water meth works.
     
    B E N likes this.
  12. B E N

    Joined:
    Nov 22, 2016
    Agreed. You can avoid hosing your IAT sensor down.
     
    Last edited: Jun 26, 2024
  13. Forcefed86

    Joined:
    Nov 24, 2005
    Not with a meth soaked thermocouple, that’s for sure! Water/meth works great. I use it on all my setups. It acts is more like race gas though, not a charge cooler. Esp. the tiny volumes most kits spray. There is a formula you can use to calculate actual air temps semi accurately if you are interested.

    Think of it as pulling X amount of heat over Y amount of time and it makes more sense.

    Your IAT probe is stationary. So say you are spraying alky for 12 seconds. The tiny surface area an IAT probes thermistor does not heat soak much. (it’s the size of a match head) So blasting it with meth for 12 straight seconds pulls a ton of heat from it. This is what your IAT gauge reads. That has nothing to do with your actual air charge temp. That is simply the temp. of the sensor tip.

    Similar to carb’d E85 people thinking a frosty intake manifold means the air charge is a similar temp. The intake manifold is stationary. The entire time the engine is running its being sprayed with alcohol and having heat pulled from it over time. All this means is the manifold is “using up” ethanol’s cooling capacity before it gets to the combustion chambers. It’s basically wasting energy that would be better spent cooling the CC. You can have 300*++ charge temps with frost on your intake manifold.

    You have to realize how quickly an engine consumes air and spits it out the tail pipes. The air is in and out of the engine in milliseconds. There is very little TIME for the water/meth to “pull heat” from the charge.

    You can easily see the reported temps are BS on a dyno. An intercooled setup at say 15lbs reporting true 80* charge temps will make a TON more power than a water/meth kit and no IC reporting the same IAT. If the charge temps people see with water/meth were accurate, it would mean tiny amounts of water/meth are more efficient than intercoolers… which is clearly false.
     
    Last edited: Jun 26, 2024
  14. saltfever

    Joined:
    Nov 15, 2007
    Thanks for the reply and my apologies for my slow response. You presented a nicely detailed reply with some very interesting concepts. Here are a few thoughts I hope are not considered too argumentative. I know you understand the theory but I am repeating it in places where your perspective is different. Your quote follows in blue italic

    Your IAT probe is stationary. So say you are spraying alky for 12 seconds. The tiny surface area an IAT probes thermistor does not heat soak much. (it’s the size of a match head) So blasting it with meth for 12 straight seconds pulls a ton of heat from it. This is what your IAT gauge reads. That has nothing to do with your actual air charge temp. That is simply the temp. of the sensor tip.

    The phase change (evaporation) from liquid to a gas is endothermic (absorbs heat) for both water and methanol. Under the right conditions this phase change takes place 10x faster than your millisecond time frame. For all practical purposes it is almost an instantaneous cooling effect. That means the time through the engine is irrelevant. An IAT at the back of the manifold is surrounded by gas molecules, not a liquid stream. If the IAt is being wet by liquid of any kind it is in the wrong place. By the time a gas has changed from a liquid to a gas it is at its correct endothermic temp.

    Similar to carb’d E85 people thinking a frosty intake manifold means the air charge is a similar temp. The intake manifold is stationary. The entire time the engine is running its being sprayed with alcohol and having heat pulled from it over time. All this means is the manifold is “using up” ethanol’s cooling capacity before it gets to the combustion chambers. It’s basically wasting energy that would be better spent cooling the CC. You can have 300*++ charge temps with frost on your intake manifold.

    A manifold frosts because it is cooler than the outside air and water vapor (humidity) condenses on its surface. Heat flows in one direction only, from hot to cold. I agree the manifold is adding heat to the the fuel mix (or the mix is absorbing heat from the manifold) and the mix may not be as cold as possible but if the charge temps were 300* the manifold would be hot and not frosted because heat flows only one direction, hot to cold. In my experience the manifold frosts during idle and other low volume events when there is no boost (no compression heating). However, at the end of a run the manifold is dripping wet or completely frost free and usually hot if there was decent boost.

    You can easily see the reported temps are BS on a dyno. An intercooled setup at say 15lbs reporting true 80* charge temps will make a TON more power than a water/meth kit and no IC reporting the same IAT. If the charge temps people see with water/meth were accurate, it would mean tiny amounts of water/meth are more efficient than intercoolers… which is clearly false.

    Water is a loser. All it is is an octane booster (as you indicated) that smooths the flame front and may inhibit detonation. However, every water molecule displaces a fuel molecule! Taking fuel out of a motor is stealing HP. Water/meth combination will always steal power compared to a similar setup with an IC only. I agree the IC setup will produce more power but it is not because charge temps are phony. The dyno is reporting how much the water is hurting you.
     
    Punk.Kaos likes this.
  15. Forcefed86

    Joined:
    Nov 24, 2005
    Not at all, always happy to discuss!

    Under the right conditions would be the key phrase there, IMO. What a typical water/meth kit does is FAR from ideal. Also, time is always relevant, you can’t ignore physics! What you are claiming is physically impossible and easily proven so. If what you say were true, W/M injection (any form of it) would be more efficient than intercoolers as a charge cooler. But it clearly isn’t. Why is the question most don't understand.

    IMHO...

    1.) The droplets are not fine enough for efficient atomization. (no matter what your water injection vendor tells you) Fog the stuff at 300-2000 bar like a diesel injector right at the valve and you’d have something. But pissing it out at 200-300psi through a 5-10gph irrigation nozzle in the charge pipe is pretty weak sauce.

    2.) The majority of the “work” done occurs at the phase change/boiling point of the liquid being injected. Which directly relates to how well it can cool. IE once your charge temps hit 212*, pure water does VERY little to cool the charge further. You also need to factory in the boiling point rises with pressure. So the phase change of a fluid passing through a charge pipe at 15-30lbs of boost will be MUCH higher. The boiling point of water at 15psi is 257*. Methanol is better, but far from efficient when compared to even an average A2A intercooler.

    3.) The volume of air is massive compared to the volume of fluid injected. No vendor kits spray anywhere near enough volume to ever be as effective as a charge cooler.

    Due to the above (and more) the cooling effects are from instantaneous. If W/M was that efficient of a charge cooler, intercoolers would be obsolete.


    Your theory of all the fluid being evaporated is incorrect. (at least in every application I've seen) This is easily seen by anyone that has sprayed a significant amount of dyed fluid through the motor. You can see where fluid puddles as it stains the intake runners, pistons etc. I run my IAT sensor at the base of my 4150 style intake manifold. (Though I run an elbow and EFI). Fluid stains and droplet patterns are easily seen in the manifold and even on the pistons. Fluid is definitely all over the intake tract. Id say my setup is better than most atomization wise. Injected pre-turbo (w claimed 5 micron nozzles at 300psi). The turbo helps to atomize as well. I run no intercooler, so the charge temps are relatively high to assist with atomization as well. But I can still clearly see where fluid puddles.

    If you need further proof, look at “WARPED PERCEPTIONS” YouTube channel. He placed a camera inside the intake manifold of his supra with 50/50 water meth sprayed after the intercooler. Pretty neat footage. Very “moist” in there to say the least!

    The only way to really calculate the charge temps would be to have a large air flow meter on a dyno cell. Then run it with and without the water meth. Then use the airflow changes reported by the MAF and a formula of HP gain VS temp. removed. Once this has been done (which is has) you can use a basic formula to calculate the amount of fluid needed to remove X amount of heat from the air charge. What makes this tricky is the amount of air you are flowing directly impacts the amount of fluid needed to cool it. IE it was calculated that at 1000hp worth of airflow, 8gph of straight meth drops air temps roughly 15*. At 500hp worth of airflow that same 8gph drops temps roughly 30*. So if your charge temps are 300* and you make 1000hp you’d need 53gph to remove 100* form the air temps! No kits are spraying this kind of volume, yet they report MUCH cooler temps.

    As with anything performance I’d say it depends on application. Travis Quillens Big Block EFI setup as an example. He used 4 maxed out 2200cc injectors sprayed at the throttle body with 100% meth. (no intercooler). At 35psi it would generate 400* plus charge temps. Yet on the engine dyno the manifold would be cold to the touch, even during a pull. These are the guys that claimed it produced visible frost on the dyno cell. I’ve never seen frost on anything personally. Just cool manifolds and condensation.

    upload_2024-7-9_11-24-56.png #ad


    My own personal car maxes out the 255* GM IAT sensor before the 1/8th. Without W/M active. Charge calculator formula suggests my temps are around 278* at 15lbs. I spray 6gph of 50/50 at each turbo inlet. (12gph total) My 5.50 ET and 128 mph trap speeds are identical with the W/M on VS off. It basically does NOTHING for performance. Yet my plug reads much cooler heat wise on the strap with it on. This is why I run it. Its basically just anti-knock protection, pulling heat from the CC. Which is why I say its more comparable to race gas, and less comparable to an intercooler/ charge cooler.

    I agree for the most part. Water isn’t as effective UNLESS you have the ignition system to take advantage of it. Most cars don’t have near the fire power ignition wise to inject high volumes of water.

    If you look up RICE RACING in Australia, they make some pretty impressive “water only” kits and lean on them pretty hard. Lots of info on their website.

    https://www.riceracing.com.au/Donmega_Waterinjection.htm

    If you look at the WWII papers done by Frank Walker on the 2900 “wasp” radial engines. You can see how effective straight water can be under the right circumstances. They were running 70+ manifold pressures at near stoich AFR with TONS distilled water only claiming 3800 HP in the dyno cells. Water literally pouring out the tail pipes the whole time.

    I can’t find the old reports with more details. But here is one.

    http://www.enginehistory.org/NoShortDays/Development of the R-2800 Crankshaft.pdf
     
    Last edited: Jul 9, 2024
  16. Novi347

    Joined:
    May 29, 2024
    So back to one of my original questions. What IATs can be expected under street driving under non-intercooled conditions? Its common to see supercharged combinations go without intercooling and am wondering what temps differences are usual. With the current ambient temps here at 118deg F, how much does an intercooler contribute to aiding IATs.
     
  17. Forcefed86

    Joined:
    Nov 24, 2005
    Can’t answer your question without more information… depends on your actual inlet temps, as well as your intercooler and turbo efficiency. If you want to roughly see what your charge temps are at a specific boost level, just look at a charge temp calculator. They have one for both intercooled and non intercooled here.

    https://www.stealth316.com/2-turbotemp.htm

    Just cruising around your inlet temps aren’t going to change. The turbo isn’t actively making boost then so the temps will remain ambient… or close to it. An A2A cooler can’t cool below ambient. A good A2A cooler that is sized correctly for the CFM you are flowing is about 70%-80% efficient.
     
    saltfever likes this.
  18. Novi347

    Joined:
    May 29, 2024

    Thank you for sharing that link!
     
    Forcefed86 likes this.
  19. saltfever

    Joined:
    Nov 15, 2007
    Another trick is to set up some nozzles to spray water on the outside fins of the IC. The phase change increases cooling and improves the IC efficiency. However, how long is a full pull on the street. 4-6 seconds or less? It's hardly worth the plumbing hassel for such a short burst. Gasoline evaporation drops the manifold temps below ambient anytime you are cruising and under low MAP.

    Forcefed thanks for the links. I remember some of the P&W experiments but have forgotten all the good stuff! LOL. I do remember the study by an army Captain about the oil cooler for the P-51 Mustang. He proved that the heated air from the oil flowing through the scoop provided enough thrust to offset the drag from the scoop. Essentially, it was about aerodynamically neutral in drag. Sorry for the thread-drift . . . my bad! lol
     
  20. Briansshop

    Joined:
    Dec 12, 2006
    The charge temp calculator put my IAT at *220. I'm actually,so far,at about half that. ?
     
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