How much boost without IC

[ATaylorRacing]

I had an over-the-motor-and-through-the-hood inter cooler burst the side with a nitrous sneeze......I replaced it with a piece of exhaust tubing....still running 14 psi of boost....results, still just as driveable as before BUT 1/4 mile ET went from 14.0s with it to 15.0s without it......Get one!

[Marcus86GLHS]

is reliability and durability important? because if it is (like it should be) just ask yourself: did dodge ever build a turbocharged car that was setup from the factory to achieve 12 psi of boost or more without also being equipped with an intercooler?

if reliability and durability are not important at all then run whatever boost you want w/o intercooling.

[whistlin']

Quote:

Originally Posted by sleeper_1 On the 2.5 L motor how much boost could you run with water injection but no IC. I am thinking about the Devilsown kit with progressive controller. I have WB for tuning, could add 5th fuel injector if required. (But prefer not to, NOT looking for big power). It's for low milage stock misu T1 motor. G-valved. Stock exhaust. Will probably go to 2.5" exhaust with high flow cat & muffler soon.

Sorry but I had to quote the original post seeing how some people misread it and thought he was asking for opinions on whether to run water/meth injection OR an intercooler.

[glhs441]

I am going to run a direct port Devil's Own kit on my TIII with no intercooler and 25psi.

[t1turbo]

why in the hell would anyone run less than premium gas.
#1 you get better gas milage on premium. So it actualy costs the same as low grade to use.
#2 Premium provides a cushion of high octane to protect the engine from detination during overboost or a hot day. Its a win win!
#3 On a non-IC you should never run anything less than premium "that is unless you drive like Rob".

[sleeper_1]

Quote:

Originally Posted by whistlin' Stock injectors with 255 Walbro and pressure set to stock. Running a 50/50 mix and 14 degrees of timing on 89 octane fuel I can run an easy 18 psi with no detonation.

That's the answer I am looking for. Thanks.

So you are not even adding extra fuel other than what's in the 50/50 mix. Did you run that set up in the summer time, hot days? The bigger turbo probably reduce the heating. I am going to stay with the stock Misu, that would heat the air up more for the same boost.

Where did you have the water injector placed? You really like the progressive system?

I G-valved my T1 to 12.5 PSI and runs 94 octane. I am surprised you could run that much boost on 89 octane. I've got to try that.

[ZachT]

i never experienced the alky injection without an intercooler i added it to my glh after i had a large npr already in it. i got the alky just for safe insurance. im running a 7gph nozzle, start at 10psi full at 20. im waiting on my TU 3in exhaust, and i just put on one of their s70 turbos, with a 3in SV, im excited to get this thing on the road.

now remember with alky injection, you have to gap your spark plugs down a bit, i was running a .035 gap, missing like a mo fo. i gapped them down to 27, no more miss. i was running -20 ww fluid.


edit, ive heard of 1400hp mustangs running no intercooler and alky injection, turbos of course. i think its an awesome mod to something that doesnt have an intercooler.

[bfarroo]

Quote:

Originally Posted by t1turbo why in the hell would anyone run less than premium gas. #1 you get better gas milage on premium. So it actualy costs the same as low grade to use. #2 Premium provides a cushion of high octane to protect the engine from detination during overboost or a hot day. Its a win win! #3 On a non-IC you should never run anything less than premium "that is unless you drive like Rob".

Actually you get worse fuel mileage if the engine doesn't require it as higher octane fuel burns slower creating less power. The engine needs to be designed/tuned to run effectively on the higher octane.

Higher octane is less prone to detonation because of this. If your car is in good tune with a healthy fuel system there's no problem running 12 psi on a no IC'd car. I've been contemplating adding a DO kit to my DD that is currently running 12 psi to get some better cooling but may go with a water/air unit for packaging reasons.

[turbokid]

shouldn't all turbos be running premium??? I know that if its stock and your nice to the car, base fuel is acceptable (not necessarily ideal). I have also had the question on how much boost w/o an intercooler. I know forsure the car is going to get intercooled with a lil more money but I dont have that and just ordered a g-valve for my 2.5 lebaron. Would 12 psi be pushing it a lil?

[whistlin']

Quote:

Originally Posted by sleeper_1 So you are not even adding extra fuel other than what's in the 50/50 mix. Did you run that set up in the summer time, hot days? The bigger turbo probably reduce the heating. I am going to stay with the stock Misu, that would heat the air up more for the same boost. Where did you have the water injector placed? You really like the progressive system? I G-valved my T1 to 12.5 PSI and runs 94 octane. I am surprised you could run that much boost on 89 octane. I've got to try that.

That's correct, no extra fuel. But my fuel system is healthy. Summer and winter same mix, same fuel.
The little mitsu will make more heat, especially at the higher boost levels.
I have the injector placed right before the throttle body. I've read that the farther it has to travel to the cylinder the more time it has to cool the air. I haven't done any experimenting with different placements.
I have my progressive controller set to start at 5psi and max at 18psi. That's the nice thing about the progressive system, it's very tunable. Every car is going to react differently so it will take some tuning.

[whistlin']

Quote:

Originally Posted by t1turbo why in the hell would anyone run less than premium gas. #1 you get better gas milage on premium. So it actualy costs the same as low grade to use. #2 Premium provides a cushion of high octane to protect the engine from detination during overboost or a hot day. Its a win win! #3 On a non-IC you should never run anything less than premium "that is unless you drive like Rob".

bfarroo is correct, octane beyond what's required is a waste of money. In reality I could get better mileage by running the 87 octane regular. But around here the regular is 10-15 cents higher per gallon than the 10% ethanol blend 89 octane. Plus I like the ethanol to clean the fuel system.
I have a diesel I can spend $4/gallon to drive, my little TD is my daily driver so I'd rather spend $3.01.
I have mentioned in other threads that water injection is "octane on demand". It's there when you need it but you're not paying for it all the time. I know most my driving is done on the vacuum side of the gauge.

[kermit]

89 octane for $3.00....where?? lol

I'd be so happy to get 87 octane for $3.00!!!

[The Pope]

Quote:

Originally Posted by t1turbo why in the hell would anyone run less than premium gas. #1 you get better gas milage on premium. So it actualy costs the same as low grade to use. #2 Premium provides a cushion of high octane to protect the engine from detination during overboost or a hot day. Its a win win! #3 On a non-IC you should never run anything less than premium "that is unless you drive like Rob".

The problem is you have to run a spark curve that matches your octain. Many newer cars like a R/T Dakota or Jeep 5.9 have a computer with more timing to be matched with the higher octain. When you run less timing the premium fuel makes the mix more rich by burning too slow too late. You can get better mileage with premium and a computer made for it but not with a computer made for regular. If your running high boost without a water type injection you should be running premium to save you from high boost detonation. These guys are putting out the fire with water, dropping the temps of combustion.

You guys with injection should be pumping it in before the compressor though. Many doing this are using the 1 piece intake and adding the alki at the TB. It doesn't get atomized right and can puddle in the chicken gizzard neck plenum of the 1 piece. You guys either need to put the injector where it belongs or buy a 2 piece intake at least. The whole reason to take off an intercooler to run that injection is to use the compressor to atomize it. You can't if you also run an intercooler, yet how many of you actually installed it without an intercooler and at the TB?

The issue of extra fuel into a 1 piece has been dangerous for a long time, but mostly with guys running extra fuel injectors. The 1 piece is a bomb waiting for the next back fire to go off when you add something flamable to the TB side. Water injection causes other issues, puddling water. Make sure you always let the engine "clean out" after every hard run. Many racers shut down there engines all the way after a pass, which out right isn't good for any turbo car. So it is good to dry the intake and cool the turbo with a couple minutes of idling after a pass. In the 70s you couldn't buy a good IC, the tankes were bolted on and they leaked and were sad. Water injection was really popular in the 70s and is one of the oldest turbo mods. Many suck through carb turbo kits also came with water injection.

[glhs441]

Up on further discussion with authoritys on alky my previous idea my not be possible,
as I am told that I would have to run so much alky to replace the cooling effect of the intercooler that it would be pig rich and not make very good power.

[whistlin']

Quote:

Originally Posted by The Pope You guys with injection should be pumping it in before the compressor though. Many doing this are using the 1 piece intake and adding the alki at the TB. It doesn't get atomized right and can puddle in the chicken gizzard neck plenum of the 1 piece. You guys either need to put the injector where it belongs or buy a 2 piece intake at least. The whole reason to take off an intercooler to run that injection is to use the compressor to atomize it. You can't if you also run an intercooler, yet how many of you actually installed it without an intercooler and at the TB? The issue of extra fuel into a 1 piece has been dangerous for a long time, but mostly with guys running extra fuel injectors. The 1 piece is a bomb waiting for the next back fire to go off when you add something flamable to the TB side. Water injection causes other issues, puddling water.

Interesting hypothesis but with no hard evidence that's all it is. I do have the one piece, I do inject before the throttle body. No problems with puddling.
Good discussion though.