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"DANNY TANNER!!!"
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1,847 Posts
Discussion Starter #21
whoa, can you link me to the site where you bought your techedge??? that's really cheap. What's the catch??? :

but yea my next mods will be wideband o2, then S-AFC2.
 

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TheFastCoonAss
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6,083 Posts
Wow "Danny Tanner", that's a good looking engine bay! Your car has come a long ways since you joined here. Also, good to hear the results are there.
 

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Premium Member
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4,409 Posts
no offense but your info is wrong. The wastegate sees boost pressure off the turbo outlet, your boost gauge sees it off the manifold, presumably there would be more pressure drop with the stock ic, but it wouldnt be even close to 5psi @ ~10 psi, especially after only one run.

If you are hitting fco at 12-13 then youre not noticing any extra boost as the air has already been metered, and if you run colder denser air (due to less pressure drop) your fco will go up, in which your description it hasnt.

this leads me to beleive your stock ic was probably leaking like 75% of stock ones ive seen, but no one notices.

Im not saying its not a good upgrade, but you wont have any noticeable power gains (butt dyno), unless you had a problem before.
 

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"DANNY TANNER!!!"
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1,847 Posts
Discussion Starter #25
no offence to you ang, but this is my car and i'm the one driving it. The thing hauls SOOOO much ass now it's unbelievable. Night and day difference over the stock IC and stock pipes.

I also did a highway run just now and in 4th gear, i slowly let the boost rise and then tromped on it. I hit fuel cut at 14PSI and this is without any boost contoller at all. This is simply the best and most amazing upgrade i've done and i have to thank Randy for designing it.

Now, is there any way to lower the boost pressure a bit so i can stop hitting fuel cut???
 

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hooligan
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475 Posts
if you're hitting 14psi without any kind of a boost controller either you guage is wrong or something in the stock boost regulation isn't operating correctly. Check your wastegate on both ends.

The colder, denser air, and not making the turbo work as hard to get the boost to the manifold does result in more horsepower, but like ang said, the FCO should have actually increased, not decreased. Double check for leaks too, especially make sure all your couplers are fitted up cleanly and the clamps are good and tight, and seated correctly. Nothing drops FCO like a bunch of lost metered air after the turbo.

Truth is, the stock intercooler never was a good design. Once I get the new clutch, that's the next thing going in.
 

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"DANNY TANNER!!!"
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1,847 Posts
Discussion Starter #28
i have an autometer boost gauge. Not sure how accurate it is, but i'm sure it's close enough.

I'll replace my vacuum line that runs from the turbo to the wastegate to insure i don't have any leaks, because 14 PSI is a damn lot to gain just by swapping intercoolers and pipes. I also have to get some more T-bolt clamps as some of my couplers are held on by the regular ring clamps.
 

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make that blkGT4294 LOL!
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827 Posts
FCO should have decreased as measured by a boost gauge. Efficiency people, it's not that effing hard. Think about it and get back to me if you can't understand. What sensor measures what?

AFM=air velocity at a known pressure (atmospheric): Volume is calculated!

Manifold boost gauge: Pressure at manifold (duh). NO VOLUME of air calculation can be based on manifold pressure alone! Look at the VPC for heaven's sake, it requires a temp sensor.


Volume of air is all we need to be concerned with. Which sensor measures that? The AFM comes close the boost gauge is NOT in the ball park.

I hit FC at 12 PSI on a Lexus/550 with a -60 turbo ( might have had a Spearco too, been a while).


Why don't we all make a comittment to thinking about physics before we post? We can't change the laws!

LOWER MANIFOLD BOOST PRESSURE WHILE MOVING THE SAME OR MORE AIR IS A GOOD THING!!!!!!!!!!!!!!!!!!
 

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hooligan
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475 Posts
blk72t: you saw FCO at a lower pressure because of the 60 trim. Colder, denser air is means less volume (therefore less pressure) for the same fuel, and yes you see a degree of that with the improved intercooler, but more importaintly you see more of what's produced at the turbo making it to the manifold. If you look at either part alone you get an opposite answer, when you look at the whole picture you'll see lower FCO for a significantly more efficient turbo, or a more efficient IC with the same pressure drop, but when you're talking about a 3psi+ pressure drop difference it should result in a slightly higher FCO.
Point is, he shouldn't be seeing nearly as much boost at the manifold as he is.
 

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make that blkGT4294 LOL!
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827 Posts
Spiv said:
blk72t: you saw FCO at a lower pressure because of the 60 trim. Colder, denser air is means less volume (therefore less pressure) for the same fuel, and yes you see a degree of that with the improved intercooler, but more importaintly you see more of what's produced at the turbo making it to the manifold. If you look at either part alone you get an opposite answer, when you look at the whole picture you'll see lower FCO for a significantly more efficient turbo, or a more efficient IC with the same pressure drop, but when you're talking about a 3psi+ pressure drop difference it should result in a slightly higher FCO.
Point is, he shouldn't be seeing nearly as much boost at the manifold as he is.
Dammit, I tried to simplify by talking about volume. Volume doesn't mean anything either, what the AFM is ACTUALLY doing is extrapolating moles. Moles are literally defined as # of molecules in a given volume. Moles NEVER change but pressure, volume and temperature do. As such, you are wrong. All that really matters in an internal combustion engine is the ratio of Oxygen atoms to gasoline atoms. If you improve efficiency anywhere in our intake setup, you will see FC at a lower manifold pressure.

Point is, yes he should.
 

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hooligan
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475 Posts
yes, the afm is extrapolating moles. However, what the efficiency of the turbo an intercooler are going to determine is just what pressure that molar quantity is going to show on the boost guage when it all gets to the manifold. So yeah, the same "n" in an inefficient system means a higher reading on the guage (PV=NRT, you increase temperature for the same n [number of moles] and a fixed volume [your manifold]) means higher pressure. Since he's improved the efficiency of the system, his guage reading should have decreased for the amount of air coming through. That's part one, and where your logic ended.

Except one factor: a big nasty restriction halfway through was eliminated, so now he's suddenly seeing a lot more of that pressure making it to the manifold (this gets a little complicated, but basically pressurizing the intercooler before means the intake and internal temps reletive to the intercooler are higher, decreasing the efficiency of the turbo and increasing the efficiencty of the intercooler, then decompress as they exit the intercooler, at the same time dropping temperature [back to PV=nRT, except since we're talking about a series of basically small valves meaning more molecule to molecule contact and we're going to have to involve a and b in this, which actually is going to have a cooling effect on the intercooler and...ah hell, let's not get into that]. Alright, I failed on 'basically' there, but pressure before and after the intercooler on the stock system is drastically different. It screws the pooch.

According to your logic, he should see a decrease on his guage, but the same FCO for the same AFM reading. He's seeing an increase on his guage, but the same FCO for the same AFM reading. Just by this we have to assume he's seeing a higher FCO/psi simply because, well, having increased the efficiency of the system it would mean his old FCO on the stock IC was something meaningfully above 14psi. He's already stated he does not have a lexus AFM.
 

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Registered
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927 Posts
12psi fuel cut is NORMAL. It depends on so many variables - I used to hit 16psi fuel cut, sometimes 11...
You may have seen gains from the IC & pipes but it's only because something was wrong before as Ang stated before. Guaranteed...Neither of those things affect power on a stock turbo at fuel cut...No way, no how. Not to mention it's not exactly 30C outside so heatsoak doesn't even begin to come into play as a possible factor...etc etc.
 

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hooligan
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475 Posts
oh, and as for whether a person can gain any power by going from turbo and IC at FCO to stock turbo and a better IC at FCO, yes, you're talking about the same amount of air and gas in the engine, but since you're starting from a lower temperature detonation is considerably less likely. Meaning you can be more agressive on timing (or in our case, the TCCS isn't going to pull timing as agressivly). Obivously his huge power gain comes from going from an inefficient 7psi under FCO to an efficient 12+psi @ FCO. Not to mention I bet it feels like it kicks you in the ass a little better since the turbo isn't fighting to spool as much (even if it has more volume to compress)
 

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86.5 Turbo
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1,571 Posts
14 psi with that intercooler and pipes makes cents. When I upgraded my intercooler to BIC's old one boost would creep to 11psi. When BIC changed to this intercooler from the one I upgraded to he said he gained another 3 psi. As for fc, because of the increase in flow fc dropped about .5 psi but it felt more powerfull at that boost level.
 

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ma70-7m=1JZ
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2,517 Posts
Dont worry my engine bay has a 1JZ in it now :bigthumb:
 
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Guest
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If you don't have a boost controller, i bet you have a shimmed wastegate. So, go out there and remove that big ass nut from the actuator.
 

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"DANNY TANNER!!!"
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1,847 Posts
Discussion Starter #40
no man i don't have anything. Trust me on this one. This setup that becauseican constructed is absolutley the shit.

I think i'm going to go MAFT because this fuel cut is really annoying.
 
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