Inlet temperature help pls

All Bada Boom, Bad Big Badaboom jokes aside.

As he originally posted he was planning on running a 30 lb switch, you use these with electronic injectors to only allow the injector to be activated when there is 30 lbs of boost present in the tube so that in the event of a backfire or other malfuntion in the tube the injector is deactivated.

When you couple this with a burst panel the likelyhood of a partial failure that would allow the system to leak enough air fuel mixture to be dangerous but not deactivate the injector is highly unlikely.

This sort of system used with methanol on an F-3 provides totally adequate cooling using only the tube from the f-3 to the intake.

Pulling tractors with staged turbos use water injection due to the fact that water has twice the latent heat of vaporization, unfortunatly without the added heat of the multistage turbos these systems do not evaporate nearly enough water to cause the disired cooling with an F-3.

There are a lot of 10.5 and drag radial cars using the methanol injectors in after the F-3 that is why I suggested to him in a pm that he should go to YB to get some opinions from people who have experience with it.

Richard Gavle

 

http://video.streetlegaltv.com/video_detail.php?mId=7127

Jim Blair just had an intercooler explosion in his car last weekend. Fortunately, it was just air.

The explosion was big enough to blow the windshield out and the carbon roof off.

Would you really want fuel mixed in with the air?

 

I agree with your comments "generally" about typical H20 cooling systems (or as I call it, aqueous intercooling) requiring high prevailing temps to be adequate in normally practised form. However, when sufficiently atomized the intake heat is not as big a deal as you might think. I'm not talking the spray flow from a regular EFI injector at 75-100psig. Much finer. Same for wet fogged fuel delivery.

Even with a 30psig cut switch/algorithm there is going to still be a considerable volume of wet intake tract which could ignite at a moment's notice. Better have a few burst panels unless the tubing and adapters are stout. Might even want to have an intentional sacrificial section of "weak" tubing.

Yes, fogging with fuel, instead of intercooling, does drop the temps considerably as measured in the manifold, but remember it's all about what happens inside the chamber once all of the valves have closed. Measuring in the manifold is just a means of estimating the cylinder conditions. Ideally, one would (and can) measure the in-cylinder conditions.

I don't dispute that there are a lot of guys fogging the tracts of centrifugals or turbos and avoiding engine destruction, but I will say that this is not the optimal solution from the point of view of either max power or cylinder balance or wallet protection.

Again, take a look at what the size constrained Ecotec import drag guys are doing. If you look at the math & thermodynamics, then it it does not take long to realize that the "power density per litre of displacement" is sharply affected (positively) by having a dry air to ice/H20 intercooler onboard where the rules permit.

If you think that perhaps you have cooled the air/meth mix "too" much with the air/liquid intercooler, then simply add more static/dynamic compression. The motor will generally love it with meth........

 

Ok just got back from the Track well it cooled it but it ran all screwed up first when it was to cold the car wouldnt even make it up on the two step . after a cpl pulls it did first we leaned it out 20% didnt make a difference then fattend it up 20% so then it went up on the two step car ran like a bag of crap the safetys came on which means it shuts down the cylinders if EGTS hit 1200 deg or what ever we had it set to anyways car is back on its way to the shop we are putting the old tube back in and taking the intercooler out . now the dilemma is it only dropped to 57 lbs of boost we thought it would drop more but it didnt and ran like crap . so the only other change we have made to the car is going from 8.5 to 10.5 compression could that in itself be responsible for 14 more pounds of boost as everything else is the same as when we used to run 43 lbs of boost on gasoline with the intercooler . so We were wrong as to our inlet temperatures thinking they were 400 deg they arent . We are going to put the smaller F3 back on the car . we have 8 injectors just above the intake ports electronic they flow 700 lbs per hour each . funny thing was with the intercooler we hit the Egt safteys right away even in the burnout and we were using over 4400 lbs per hour of fuel doesnt make sense to us . only thing we can say is when we initially came out with less overdrive on the blower and only making 50 lbs of boost and we leaned the bottom end out first gear with 30 deg of timing and a 4.2 to 4.3 air fuel ratio the car ran like jack the bear but as soon as you hit high gear the egts would get to high and we were shutting off cylinders and the af ration in high gear went to 3.8 when we tried to lean it out made it worse . We do have two other port nozzles that we can turn on in the intake elbow that fan the fuel spray out and the larges jet they will take is an .080" jet as that is the size of the hole we control those with a nitrous solenoid off the fuel rail and they will dump as much as 1100 lbs per hour of fuel in when activated . we can control those either with low hi gear map or with boost pressure . We are just very paranoid about putting in injectors right after the blower Im sure you understand and trust us we have blown intercoolers up in the past as well and blown the back window out of the car .Your help appreciated as we are back at the track tomorrow if we cant get a handle on this thing and make it run a hi 6.40 no point in going to vegas Ps the intercooler and all the stuff added 175 lbs to the car .could our problem be camshaft ? 283 288 at .050 same cam we used on gas . put it this way on gas we ran 210 mph at almost 2600 lbs a 6.65 now we have run a 6.63 with a 2415 weight and only 207 mph cant get the backhalf to run at all with the new combo . it will burn the plugs off and nip pistons about 1280 to 1300 deg .

 

I don't have any personal experience with an F-3 but I also wondered about the 400 degrees and 70 lbs but did not feel qualified to challenge it.

You mentioned that the only thing you changed were the fuel and compression, is there any chance you unintentionally changed the cam timing etc? this could affect boost pressure and charge temp as well as egts and performance.

In all of my posts I have said to use a burst panel on the tube and pointed out that the tube and any explosion would be on the other side of the firewall. It certainly would not be a bad idea to place a blanket around the tube assembly. Some of the guys that are fogging a passenger compartment mounted cooler or just running one dry are definatly dancing with the devil.
As far as cylinder balance goes I assumed the port nozzles were going to be used for that function just like on a roots/screw deal. I have no argument with using intercoolers I just think that you can also run very well without one particularly with the F-3 at the typical boost and temperature range they produce as compared to the boost and heat the guys making 1800 hp on a 4 cyl run into.

Richard Gavle

 

well our first thoughts are incorrect we dont have 400 deg inlet temperatures according to the perfect gas law as we now made 57 pounds of boost not the 43.75 we had originally with the intercooler on gas our inlet temp works out to 200 deg . the only change in the Engine as cam is degreed the same etc.. is the compression going from 8.5 to 10.5 to one . we have axed the cooler and will put the smaller f3 down from the 131 to the 123 and give that a shot for tomorrow . now as far as timing goes we have no idea at this point ?? so to make 57 pounds of boost from the 70 we had and we know our outlet temp is 80 deg with the intercooler that formula works out to 200 deg to make 70 pounds of boost of which is way to much for what we are doing we know that . as to why we keep getting high Egt temps could that be to much timing we normally run 25 deg and 30 on the two step . can figure it out as without the intercooler and we weighed the car again today it adds alot of weight as we were 2590 not the 2415 before . why wont this car go any faster on alcohol as its lighter has gone from 8.5 to 10.5 compression and its on alcohol and from what we are to understand makes up to 14% more power than Gas .When we did first come out though we ran 50 lbs of boost and had to lean the car out to get a decent number when we fattened it up to keep it off the Egt overides car slowed down 12 mph and went 7.0s

 

Hi Dan.
You have had the car going well into the six`s so I appreciate that you have a very good understanding of what you are doing and I respect that a lot. Like you seem to be, I also am a advocate of strong theoretical knowledge and like to compare the theory to the practical facts/measurements to double check both methods. With the above in mind I put the following in the arena for discussion.
My basic understanding of high EGT`s is
-lean mixture
-retarded ignition timing
-lots of power
Hopefully some of the more experienced players out there can add more detail and some possible remedies to my most basic list.
Regards.
Jim

 

just thinking out aloud...
what ignition you running?
we run ttsbc , mfi , 30 + psi boost , and had to use a msd 10 to burn the meth fuel.

the msd 7 never cut it,
the msd 10 actually was cooler in egt , probaly due to burning in cylinder not in pipes...

cheers
ash

 

We run the Kam system it uses 8 individual coils. plugs at .020" ngk 10s . Just leaving to track now appreciate everyones thoughts . occured to us last nite better double check the map sensor as you never know if its out maybe that would explain why we have High boost levels as at this point nothing is making any sense . We have been banging our heads against the wall for 45 passes this year and nothing is working as it should .yes our initial thoughts were burning in the pipe as well .But dont feel this to be true as adding more fuel does lower the EGTS just slows the car down way to much to actually make it down the track we will run 7.0s and in reality the car should run 6.50 falling out of a tree .

 

You should call Billy Martone, he has run an f3 on a hemi injected alcohol in outlaw 10.5. He ran a KAM system also He can probably give you some good info. Nice guy, tell him i told you to call
254-624-1495

 

Well we found the problem its in the computer system . our map sensor was reading 30 lbs of boost on the two step with the small blower that wasnt the case as we hooked up a small gauge autometer and it was only 17 lbs so that was throwing off our whole fuel map . we did run ok in the bottom half of the track today .983 60 foot 2.74 330 and 420 to eigth backed up but as soon as it goes past the eigth mile the map goes off the scale and starts doing weird crap to the engine af will go from 3.8 bounces up to 7.8 and starts to run crappy its a map sensor problem . ran a 6.56 at only 200 mph with cylinders not firing properly past 900 feet Egts were averging only 1130 so the problem is somewhat sorted out . now I have a question as we suspect the Egt calibration to be off . when the car is Idling on the pro jacks the computer will read the Egts we put a temp gun on the headers and the cylinders we know to be running rich with the temp gun are around 230 deg the others around 330 deg but our computer is saying the are all pretty equal and running over 500 what gives and we have 3 temp guns and all say the same thing . we ended up kicking a rod out on the last past because we feel it pounded a bearing out as its been detonating after the 800 foot mark due to map sensor problems but generally we are happy as we have been chasing this problem now for several months . Lesson learned dont trust computer stuff out of the box as our map sensor was showing 65 pounds of boost with the small blower and we know there is now way it would make more than 40 on this engine . Hopefully our misfortunes can help others down the road . We do feel now that car will run its low 6.40s hig 6.30s once computer glitches are sorted out .thanks for all your help guys .in all new systems there can be a bug or two but we are happy overall just a learning experience for us .we chased our tail alot on this one and admittedly not working properly yet but at least we are happy to have finally found the problems as its very frustrating when your smart enough to run something and start to second guess your abilities this car really kicked the crap out of us this year but we are prevailing and sorting it out . at 1 am in the morning last nite both of us dead tired decided to call the car second guess .