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Quickstop [UK]
Combating adversyty.
Re: Compression past spark plug.
Stock trucks were 300 at 14.7 psi?
Stock trucks were 300 at 14.7 psi?
Compression past spark plug.
- Thread starter The Devils Own Chariot
- Start date
The Devils Own Chariot
Active member
Re: Compression past spark plug.
How can stock trucks be 300whp (wheel horse power) when they are rated 280hp at the crank? 100 crank horse power usually equals 80 wheel horse power on most cars. Campbell Automotive says they are 220whp on stock trucks. I called them about my dyno sheet to see if the power and torque cures looked okay.
How can stock trucks be 300whp (wheel horse power) when they are rated 280hp at the crank? 100 crank horse power usually equals 80 wheel horse power on most cars. Campbell Automotive says they are 220whp on stock trucks. I called them about my dyno sheet to see if the power and torque cures looked okay.
The Devils Own Chariot
Active member
Re: Compression past spark plug.
So you do you think the computer is shitting the bed because it has injectors at 130% DC? Is that possible?
So you do you think the computer is shitting the bed because it has injectors at 130% DC? Is that possible?
sly dvl
Ya, it's got a Turbo
Re: Compression past spark plug.
Actually, it's "on" time vs. "total" time. But you're right, I can't understand how you can have a DC over 100%.
Actually, it's "on" time vs. "total" time. But you're right, I can't understand how you can have a DC over 100%.
SloGN
9Sec Alky V6
Re: Compression past spark plug.
what do you have the gap set at? The Gn's really like a tight 28 sometimes 26 to stop the spark blow out.
FWIW using the alky as a supplemnt fuel is very dangerous. if that pump quits or the flow drops off your engine is toast. All the alky should be used for is a knock suppression and cooling. have you checked the fuel pressure you pump may not be keeping up causeing the high duty cycle.
what do you have the gap set at? The Gn's really like a tight 28 sometimes 26 to stop the spark blow out.
FWIW using the alky as a supplemnt fuel is very dangerous. if that pump quits or the flow drops off your engine is toast. All the alky should be used for is a knock suppression and cooling. have you checked the fuel pressure you pump may not be keeping up causeing the high duty cycle.
bezerk
New member
Re: Compression past spark plug.
because they were "rated" at 280. most of them made easily over 300. more like 330 etc. well. if you do a little research you might now why they were rateds low.
further than that i''m just trying to help you, but you ask a question, get given an answer or thought and you stick to your own plan.
saying your truck has 300hp stock, some drivetrainloss you make about 240hp at the wheels. so if you just wanna max out your 30psi boost gauge, go ahead, ii just think you can be alot fatser if you start to tune it at lower boost levels, so you know wassup ,and not crossthreading your sparkplug holes by looking for things that give you a miss,
because they were "rated" at 280. most of them made easily over 300. more like 330 etc. well. if you do a little research you might now why they were rateds low.
further than that i''m just trying to help you, but you ask a question, get given an answer or thought and you stick to your own plan.
saying your truck has 300hp stock, some drivetrainloss you make about 240hp at the wheels. so if you just wanna max out your 30psi boost gauge, go ahead, ii just think you can be alot fatser if you start to tune it at lower boost levels, so you know wassup ,and not crossthreading your sparkplug holes by looking for things that give you a miss,
The Devils Own Chariot
Active member
Re: Compression past spark plug.
:rotf: I understand you were trying to help. 240hp to the wheel is about right for a stock truck on a dynojet. Im saying my truck makes 300 wheel horse power on a dyno jet at 17 psi. Thats all.
:rotf: I understand you were trying to help. 240hp to the wheel is about right for a stock truck on a dynojet. Im saying my truck makes 300 wheel horse power on a dyno jet at 17 psi. Thats all.
SloGN
9Sec Alky V6
Re: Compression past spark plug.
i have been on several dyno's and the dyno jet seems to be the most accurate. if you would do the weight VS et method you can get a close power number then use that info and check out a dyno's numbers
Here in NC we are in the nascar country and i have several friends that work in that field and those guys swear by the dynojets due to the accurate number that they produce.
FWIW my truck @ 15 psi on a mustang dyno it made 203 but my truck ran a 13.77 @95.5 @ the nats in 100 degree heat. those 203 horses surely are over acheivers then :tup:
i have been on several dyno's and the dyno jet seems to be the most accurate. if you would do the weight VS et method you can get a close power number then use that info and check out a dyno's numbers
Here in NC we are in the nascar country and i have several friends that work in that field and those guys swear by the dynojets due to the accurate number that they produce.
FWIW my truck @ 15 psi on a mustang dyno it made 203 but my truck ran a 13.77 @95.5 @ the nats in 100 degree heat. those 203 horses surely are over acheivers then :tup:
blk00z28
Forced to by choice
Re: Compression past spark plug.
I don't see if you did a compression test or not? Did you, if so what was it?
How did you get the metal from having to re tap the plug hole out of the cylinder after you tapped it? If you just left it in there, I'd check your cylinder walls, you might have scored them by leaving a little metal in there after you did it. And it could effect that cylinder. Either by compression loss, or worse..
Whats your fuel cut off set at? What psi/rpm?
What fuel pump, and what psi are you at? Sure you're just not getting a pressure drop around 20psi for whatever reason and it comes back a little more into boost?
What psi do you kick your alky in at? Are you seeing the drop in AF at that point or when your just cursing, or wot?
Dude you need injectors badly. If your fighting this on stockers then you might want to out weigh the cost of a new motor vs the time it will take to learn how to tune for 50's. I used 50's and meth before my truck broke. My fuel was cut A LOT to compensate for the meth. That was the only way I could run up to 26psi safely. But I'm pretty sure my DC wasn't near 80% let alone 100. So I don't see why you'd be running full DC with meth/alky.. You said it yourself, when it dips into the 10's its loading up on fuel. If I were you I'd spray a little more meth and a little less fuel and see how the truck likes it. DON'T jack it up to 25psi when doing it, but run around 18 and see how it feels/looks on datamaster.
I don't see if you did a compression test or not? Did you, if so what was it?
How did you get the metal from having to re tap the plug hole out of the cylinder after you tapped it? If you just left it in there, I'd check your cylinder walls, you might have scored them by leaving a little metal in there after you did it. And it could effect that cylinder. Either by compression loss, or worse..
Whats your fuel cut off set at? What psi/rpm?
What fuel pump, and what psi are you at? Sure you're just not getting a pressure drop around 20psi for whatever reason and it comes back a little more into boost?
What psi do you kick your alky in at? Are you seeing the drop in AF at that point or when your just cursing, or wot?
Dude you need injectors badly. If your fighting this on stockers then you might want to out weigh the cost of a new motor vs the time it will take to learn how to tune for 50's. I used 50's and meth before my truck broke. My fuel was cut A LOT to compensate for the meth. That was the only way I could run up to 26psi safely. But I'm pretty sure my DC wasn't near 80% let alone 100. So I don't see why you'd be running full DC with meth/alky.. You said it yourself, when it dips into the 10's its loading up on fuel. If I were you I'd spray a little more meth and a little less fuel and see how the truck likes it. DON'T jack it up to 25psi when doing it, but run around 18 and see how it feels/looks on datamaster.
The Devils Own Chariot
Active member
Re: Compression past spark plug.
.I did not do a compression test yet. Im going to try that this weekend I hope. I have a Walbro 255 fuel pump. I have base fuel pressure at 50 psi. I run my truck at the T222 setting on the ultimate. I tried T324 and it acts the same. At 18 psi the injectors can keep a solid AFR of 11.5 with no alky. Im turning alky on at 10 psi just to get the pump rolling because the turbo spools super faster after 10 psi. Truck runs very nice at 18psi, 25psi not so much.
Thanks again to everyone for your input and interest. I dont want to rub people the wrong way. I would really like to track down my issues at 25 psi or at least find out the reason before I change anything (Like going to bigger injectors). Bigger injectors might also fix it. The truck runs great even at 25 psi but when its cold. When it gets hot it then starts to break up. With all that meth and boost its a really banshee
.I did not do a compression test yet. Im going to try that this weekend I hope. I have a Walbro 255 fuel pump. I have base fuel pressure at 50 psi. I run my truck at the T222 setting on the ultimate. I tried T324 and it acts the same. At 18 psi the injectors can keep a solid AFR of 11.5 with no alky. Im turning alky on at 10 psi just to get the pump rolling because the turbo spools super faster after 10 psi. Truck runs very nice at 18psi, 25psi not so much.
Thanks again to everyone for your input and interest. I dont want to rub people the wrong way. I would really like to track down my issues at 25 psi or at least find out the reason before I change anything (Like going to bigger injectors). Bigger injectors might also fix it. The truck runs great even at 25 psi but when its cold. When it gets hot it then starts to break up. With all that meth and boost its a really banshee
Quickstop [UK]
Combating adversyty.
Re: Compression past spark plug.
Have you looked at a compressor map to see where you are sat at 25 psi with that truck? I think you might find you are losing a lot of power through the turbo. Just turning up the boost doesn't equal the corresponding amount of power.
as for 50s, they are flaky. Go with the 65s and get some of the good code 59 tunes around here as a base.
A compression test should be one of the first things you tried.
Be interested to see.
have you got any dyno runs of the power fading out?
Have you looked at a compressor map to see where you are sat at 25 psi with that truck? I think you might find you are losing a lot of power through the turbo. Just turning up the boost doesn't equal the corresponding amount of power.
as for 50s, they are flaky. Go with the 65s and get some of the good code 59 tunes around here as a base.
A compression test should be one of the first things you tried.
Be interested to see.
have you got any dyno runs of the power fading out?
The Devils Own Chariot
Active member
Re: Compression past spark plug.
Thats to bad. I have 50# injectors waiting to go in.
I dont have any fading power dyno graphs. I really do not thing that turbo is killing power. Top end is very much improved.
Thats to bad. I have 50# injectors waiting to go in.
I dont have any fading power dyno graphs. I really do not thing that turbo is killing power. Top end is very much improved.
The Devils Own Chariot
Active member
Re: Compression past spark plug.
I lowered boost to 20 psi. I had to back the boost controller almost all the way out to get 20 psi. Something is wrong there. I turned the alky off and ran 20 psi. The truck ran great even when hot. My 1st guess is the ultimate chip was cuting spark because it saw to much boost. I think the boost controller spring is to hard. Another thing is I think dumping all that alky was messing up spark even though the AFR was right. I need to get those bigger injectors in!
I lowered boost to 20 psi. I had to back the boost controller almost all the way out to get 20 psi. Something is wrong there. I turned the alky off and ran 20 psi. The truck ran great even when hot. My 1st guess is the ultimate chip was cuting spark because it saw to much boost. I think the boost controller spring is to hard. Another thing is I think dumping all that alky was messing up spark even though the AFR was right. I need to get those bigger injectors in!
Re: Compression past spark plug.
umm ALL of your dyno graphs show fading power. You're losing 60hp from 3900 to 5200 rpms....and losing 150ft-lbs. That's pretty power fading if you ask me.
How do your intake temps look from that range? Either you're blowing hot air, running out of fuel, or something else. Just becuase your top end is better than before, doesn't mean that it's running 100%.
Also, sounds like you don't have your turbo/wastegate/vacuum setup properly. It shouldn't be difficult to run less than 20psi.
umm ALL of your dyno graphs show fading power. You're losing 60hp from 3900 to 5200 rpms....and losing 150ft-lbs. That's pretty power fading if you ask me.
How do your intake temps look from that range? Either you're blowing hot air, running out of fuel, or something else. Just becuase your top end is better than before, doesn't mean that it's running 100%.
Also, sounds like you don't have your turbo/wastegate/vacuum setup properly. It shouldn't be difficult to run less than 20psi.
Quickstop [UK]
Combating adversyty.
Re: Compression past spark plug.
Have you got a compressor map of the 25g? You've got a lot of things going on there mate.
Have you got a compressor map of the 25g? You've got a lot of things going on there mate.
The Devils Own Chariot
Active member
Re: Compression past spark plug.
Campbell Automotive said that it looks like a normal power curve. Tourque always falls off hard. Do you guys have some other stock truck dyno graphs I can compare to?
Campbell Automotive said that it looks like a normal power curve. Tourque always falls off hard. Do you guys have some other stock truck dyno graphs I can compare to?
The Devils Own Chariot
Active member
Re: Compression past spark plug.
Here is a crude compressor map.
Its the TD06H
http://www.mhi.co.jp/en/products/detail/turbocharger_specification.html
Here is a crude compressor map.
Its the TD06H
http://www.mhi.co.jp/en/products/detail/turbocharger_specification.html
The Devils Own Chariot
Active member
Re: Compression past spark plug.
I think my wastegate just went bad.:rant:
I think my wastegate just went bad.:rant: