Turbo Pressure - Page 2 - PeachParts Mercedes-Benz Forum

boneheaddoctor · #16 04-11-2005, 10:35 PM

Quote:

Originally Posted by Hit Man X

What are EGTs stock? And what's in the "acceptable" limits of safe being nonintercooled?

you have to be under 1,200 F pre turbo...thats MAX acceptible, your stock EGT will vary depending on boost and tune of your IP....less fuel = lower EGT, and most of these IP's are pumping les fuel than they did new. I think my W116 was only doing about 900 F stock....need to tweak it more yet once I know my Timing is right. I plan on brazing a O2 bung and cap on the rear cover so it can be adjusted on car.

Max safe non-intercooled would be under 15 psi......but without IP mods more air isn't going to get you any more power.

boneheaddoctor · #17 04-11-2005, 10:37 PM

Quote:

Originally Posted by 82-300td

I don't know about that. I have adjusted my KKK to 20psi (By accident) and it WILL shoot up to that by 3500rpm.

but the KKK with he heating that boosted air at a porportionately higher rate than the Garret will at the same PSI ...above 11 psi.....you will be operating it way abouve its efficient range.

Hit Man X · #18 04-11-2005, 10:46 PM

Quote:

Originally Posted by boneheaddoctor

you have to be under 1,200 F pre turbo...thats MAX acceptible

Max safe non-intercooled would be under 15 psi......but without IP mods more air isn't going to get you any more power.

Yup off the manifold is where I'd install the EGT bung. Post turbo is useless. Is there a preferred cylinder to get the EGT from (one run hotter than another)?

What I've been wondering about the last few days is if you threw on an IC at stock PSI... let's say 11PSI...

If that dropped you down to 850°, any clue as to how much fuel you could gain from the IP to get back to ~1150-1200°. If that overfueled you, then I'd turn up the PSI a pound or two maybe to counter it. I'm not sure how well the stock head bolts would hold at cylinder pressures like that.

But... what I'm really wondering is how much increase in torque are we looking at with something like that? 75ft-lbs or so I was guessing with a nice IC with little pressure drop.

Lastly, which IC are you planning to install?

d.delano · #19 04-11-2005, 11:08 PM

Quote:

Originally Posted by 82-300td

The Garrett will only make 11psi without modification. The KKK turbo on the other hand will be at 20+psi before you know it, if adjusted incorrectly.

After recently tearing apart my Garrett this week I found a few things. The wastegate diaphram won't go above 11psi because it is bottomed out on it's threads (On the valve). The only stock way to go above 11psi (With pyrometer or intercooler) is to cut more threads on the valve. This will allow more spring tension and more boost. The other way is to use an external Boost Controller to the wastegate hose. I think this is cheating the easy way out, plus it looks goofy.

I also found the valve stem seal to be VERY loose and allowing soot to enter under the diaphram.

If you can live with 11psi, good for you. I'll keep my KKK turbo and 13psi.

My car has the Garrett- I road tested it with the wastegate hose plugged and the switchover valve bypassed and it went up to 17 psi, so it must go higher than 11. I don't enjoy the lag all that much, and someday I'd like to finally adjust the sucker but it looks like a pain. The threads on the ALDA are painted, screw's a good ways out. Can an ALDA that's adjusted to deliver too much fuel be a detriment to boost pickup?

boneheaddoctor · #20 04-12-2005, 08:12 AM

Quote:

Originally Posted by Hit Man X

Yup off the manifold is where I'd install the EGT bung. Post turbo is useless. Is there a preferred cylinder to get the EGT from (one run hotter than another)?

What I've been wondering about the last few days is if you threw on an IC at stock PSI... let's say 11PSI...

If that dropped you down to 850°, any clue as to how much fuel you could gain from the IP to get back to ~1150-1200°. If that overfueled you, then I'd turn up the PSI a pound or two maybe to counter it. I'm not sure how well the stock head bolts would hold at cylinder pressures like that.

But... what I'm really wondering is how much increase in torque are we looking at with something like that? 75ft-lbs or so I was guessing with a nice IC with little pressure drop.

Lastly, which IC are you planning to install?

Well I havent decided on the IC....becasue its the W116 that I have tweeked and if has the battery behind the RF headlight......and space is way tight...the W123 will be far easier...but I need to acquire another set of guages before i mess with that one and cash is tight right this moment.

The EGT pyrometer should go at the junction of the cylinders to get across all of them.....which is down near the mounting flange.

I would keep the boost under 15 psi intercooled or not.....odds are you won't get it overfueled at that level...and you know its not going to pop headgaskets at that level as the overboost protection kicks in about 16 psi.

My EGT's are still low on the W116. I turned the crew 1/2 turn CCW as other threads describe....but my observations show thats opposite the direction that it works when the go pedal is depressed..I think it should be turned clockwise....well I need to take it out to get the timing correct anyway and I will modify the cover so I can remove a cover screw and adjust it in place.

dannym · #21 04-12-2005, 09:35 AM

Quote:

Originally Posted by 82-300td

I don't know about that. I have adjusted my KKK to 20psi (By accident) and it WILL shoot up to that by 3500rpm.

20 psi?? Doesn't the overboost protection switch cut boost at 15 psi??

I have the KKK and I spent a few hours adjusting it. I had it up at 15 at one time. The gauge was fluttering a lot. I'm assuming it was the switch dumping boost.
It's really weird. The boost dropped to 11 psi from 15 with just 1 turn on the set screw. I tried to adjust it back up but I couldn't get it to work. I ran out of the time I had to play with it. I'll try again and report back.

Danny

boneheaddoctor · #22 04-12-2005, 09:43 AM

Quote:

Originally Posted by dannym

20 psi?? Doesn't the overboost protection switch cut boost at 15 psi??

I have the KKK and I spent a few hours adjusting it. I had it up at 15 at one time. The gauge was fluttering a lot. I'm assuming it was the switch dumping boost.
It's really weird. The boost dropped to 11 psi from 15 with just 1 turn on the set screw. I tried to adjust it back up but I couldn't get it to work. I ran out of the time I had to play with it. I'll try again and report back.

Danny

Keep in mind that while the turbo MAY produce a certain boost level that level may be outside of its efficient range....which means you might be overspeeding the turbo to do it...you also have to consider the charge heating.....thats why the Super-turbo guys use the bigger turbos....there is more to consider than just a simple boost level measurement.

Phil · #23 04-12-2005, 10:30 AM

Quote:

Originally Posted by 82-300td

The Garrett will only make 11psi without modification. The KKK turbo on the other hand will be at 20+psi before you know it, if adjusted incorrectly.

After recently tearing apart my Garrett this week I found a few things. The wastegate diaphram won't go above 11psi because it is bottomed out on it's threads (On the valve). The only stock way to go above 11psi (With pyrometer or intercooler) is to cut more threads on the valve. This will allow more spring tension and more boost. The other way is to use an external Boost Controller to the wastegate hose. I think this is cheating the easy way out, plus it looks goofy.

I also found the valve stem seal to be VERY loose and allowing soot to enter under the diaphram.
If you can live with 11psi, good for you. I'll keep my KKK turbo and 13psi.

The turbo that I have on my car is the KKK unit and I could only get just under 11psi. At 11psi it has good pick up but it seems like it should be capable of more. I'm going to clean all lines associated with it and see what that does.

boneheaddoctor · #24 04-12-2005, 10:42 AM

Quote:

Originally Posted by Phil

The turbo that I have on my car is the KKK unit and I could only get just under 11psi. At 11psi it has good pick up but it seems like it should be capable of more. I'm going to clean all lines associated with it and see what that does.

Unless you turn up the fuel in the IP 11 psi give you all the air you can use....any more isn't going to get you more power....

Just so you know.

Phil · #25 04-12-2005, 11:58 AM

Quote:

Originally Posted by boneheaddoctor

Unless you turn up the fuel in the IP 11 psi give you all the air you can use....any more isn't going to get you more power....

Just so you know.

I guess that moves the ip up the list of things to check. Part of the problem is that there is no record of the work done on this car for the last 3 or 4 years so I'm going through and checking everything. It seem like the po put time and money into the car as most stuff is in good shape but it needs to be fine tuned.

Hit Man X · #26 04-12-2005, 06:00 PM

Quote:

Originally Posted by boneheaddoctor

Well I havent decided on the IC....becasue its the W116 that I have tweeked and if has the battery behind the RF headlight......and space is way tight...the W123 will be far easier...but I need to acquire another set of guages before i mess with that one and cash is tight right this moment.

The EGT pyrometer should go at the junction of the cylinders to get across all of them.....which is down near the mounting flange.

I would keep the boost under 15 psi intercooled or not.....odds are you won't get it overfueled at that level...and you know its not going to pop headgaskets at that level as the overboost protection kicks in about 16 psi.

My EGT's are still low on the W116. I turned the crew 1/2 turn CCW as other threads describe....but my observations show thats opposite the direction that it works when the go pedal is depressed..I think it should be turned clockwise....well I need to take it out to get the timing correct anyway and I will modify the cover so I can remove a cover screw and adjust it in place.

Ah so when you pull the IP that's why you're going to install that O2 bung correct... so you can "adjust on the fly"?

I figure these cars have about 120hp/180tq stock... So with a bit more air to burn more fuel... any clues as to what sort of output we're talking? 50hp additional with 75-100tq

boneheaddoctor · #27 04-12-2005, 07:53 PM

Quote:

Originally Posted by Hit Man X

Ah so when you pull the IP that's why you're going to install that O2 bung correct... so you can "adjust on the fly"?

I figure these cars have about 120hp/180tq stock... So with a bit more air to burn more fuel... any clues as to what sort of output we're talking? 50hp additional with 75-100tq

No idea how much....but enough for the car to feel quick is fine by me. And basicly as much as I can get with the stock turbo and IP tweaked..........and still keep EGT in the safe range. its never going to be a fast car...I don't have the money, the resources or the talent those guys in finland seem to have. Nor do I have a buddy with a Chassis dyno to check results.

I think the common wisdom of turning the Full load screw on the 617 pump to the leftmakes no sense to me as that takes the load off that you put on it when giving it fuel.....Plus 1/2 turn CCW did not bump my EGT at all...in fact its a tad less if anything. I still think my IP is a few degrees retarded and its against the stop in the adjustment range. the rear cover is a stamped tin cover.....easy to modify.

Keep in mind only a fool will do this without an EGT guage installed.

Hit Man X · #28 04-12-2005, 08:09 PM

Quote:

Originally Posted by boneheaddoctor

No idea how much....but enough for the car to feel quick is fine by me. And basicly as much as I can get with the stock turbo and IP tweaked..........and still keep EGT in the safe range. its never going to be a fast car...I don't have the money, the resources or the talent those guys in finland seem to have. Nor do I have a buddy with a Chassis dyno to check results.

I think the common wisdom of turning the Full load screw on the 617 pump to the leftmakes no sense to me as that takes the load off that you put on it when giving it fuel.....Plus 1/2 turn CCW did not bump my EGT at all...in fact its a tad less if anything. I still think my IP is a few degrees retarded and its against the stop in the adjustment range. the rear cover is a stamped tin cover.....easy to modify.

Well ya, something worth while. I don't forsee building a custom header and adding a Holset HX50 to a vehicle worth $3000... maybe dropping the stock exhaust sure to drop EGTs and get the turbo to spool a bit. Same with spending $100 to port the exhaust housing.

What you're doing is what I've been considering since day one. An IC would make efficiency go up a good deal. Are Volvo ICs any good or do they have pretty high pressure drop?

Come now... I asked where ya'd install the EGT bung even.

boneheaddoctor · #29 04-12-2005, 08:12 PM

Quote:

Originally Posted by Hit Man X

Well ya, something worth while. I don't forsee building a custom header and adding a Holset HX50 to a vehicle worth $3000... maybe dropping the stock exhaust sure to drop EGTs and get the turbo to spool a bit. Same with spending $100 to port the exhaust housing.

What you're doing is what I've been considering since day one. An IC would make efficiency go up a good deal. Are Volvo ICs any good or do they have pretty high pressure drop?

Come now... I asked where ya'd install the EGT bung even.

Well I have been trying to figure out how to fit an Intercooler to my W116 for the last 2 years.....there is just no room without giving up A/C (ain't gonna happen) or seting back the radiator a few inches (means its gonna need electric fans and a bigger alternator)

I have only had the W123 for 2 months so havent figured that one out yet....it has far more space but has no EGT or boost guage as of yet.

Hit Man X · #30 04-12-2005, 08:51 PM

Quote:

Originally Posted by boneheaddoctor

Well I have been trying to figure out how to fit an Intercooler to my W116 for the last 2 years.....there is just no room without giving up A/C (ain't gonna happen) or seting back the radiator a few inches (means its gonna need electric fans and a bigger alternator)

I have only had the W123 for 2 months so havent figured that one out yet....it has far more space but has no EGT or boost guage as of yet.

What's the matter with putting it infront of the A/C condensor? Or does the condensor need the most amount of airflow?

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