7.3 idi max boost with head studs?
#16
12-30-2014, 09:34 PM
HD250, where are you getting the idea that the stage 1 is a high rpm WOT optimized profile? This is simply not true. The stock cam is an N/A grind with zero intake pressure and minimal exhaust pressure in mind. The stage 1 improves cylinder filling under boost conditions, which usually comes with exhaust pressure that is higher than the intake pressure. This is a benefit any time the engine is under load and spooling the turbo, not just for a ***** out dyno run. That is why it is advertized as a turbo cam grind, because it produces superior results when intake and exhaust pressures are present. The biggest thing users claim about the stage 1 is that it has great driveability and a very versatile power band on their turbo'd engine. That pretty much sounds like a "stage 1" to me. It seems a bit harsh to call that misleading. Justin has posted every specification of his grind, and given us a very honest and fair comparison of how his cam grind compares to stock, J2, and what he knows of the Type 4 grind.
Mike, Actually, the big thing to bleeding off compression is the intake valve being open longer. Overlap has very little to do with "bleeding" compression, because 9 times out of 10 (thats conservative) exhaust pressure is going to be more than intake pressure, and that works the opposite way of bleeding compression off... A cam with very little overlap and an intake event with decent duration and a late ICL is going to bleed compression off. Ill compare the Stock cam, The R&D, and The J2 below (Id toss the typ4 in there as well, but russ hasent given me the specs yet):
The stock cam has 37* of total overlap (-27*@.050"), and the intake valve stays open for 42* after bottom dead center. It effectively stays open for 7* after BDC at .050", which is a good lift for dynamic measurement.
The R&D cam is 56* of total overlap (-24*@.050"), and the intake valve stays open for 52* after bottom dead center. It effectively stays open for 21* after BDC at .050"...
The J2 cam is 56* of total overlap (-12*@.050"), and the intake valve stays open for 74* after bottom dead center. It effectively stays open for 32* after BDC at .050"...
Putting these together... The further the intake stays open after BDC, the more compression is bled off. Reversion happens when there is too much overlap at too little flow (read:RPM or boost)... The stock cam doesnt have much total overlap, but has as much dynamic overlap as the R&D (which is negative anyway, meaning both valves overlap for less than 0* of duration when the valves are open to .050" of lift...)... The J2 cam has about as much total overlap as the R&D, but has more dynamic overlap at .050", meaning more chance for reversion at lower RPM's, but when higher RPM's and boost are achieved, there is more cylinder filling, and therefore more power.... This just covers the intake side though, there is more as far as the exhaust sides are concerned...
As far as the TYP4 cam is concerned, the best I can do with the knowledge I have of it, is that it increases lower end cylinder filling by increasing duration on the intake side, but maintaining stockish lifts and timing events as much as possible... This is why it works great in low boost and N/A situations, there is no exhaust pressure inhibiting cylinder filling, and the extra filling it gets from the intake event makes a little more torque lower in the RPM range.
Basically it coems down to where you want your cam to perform... The stocker is a good all around cam for everyhing, the TYP4 is better than the stocker at low RPM, the R&D is great for engines that spend their time boosting 10-20psi while doing work, and the J2 is great for WOT/Higher RPM/higher boost situations while doing work... They all have their place...
The stock cam has 37* of total overlap (-27*@.050"), and the intake valve stays open for 42* after bottom dead center. It effectively stays open for 7* after BDC at .050", which is a good lift for dynamic measurement.
The R&D cam is 56* of total overlap (-24*@.050"), and the intake valve stays open for 52* after bottom dead center. It effectively stays open for 21* after BDC at .050"...
The J2 cam is 56* of total overlap (-12*@.050"), and the intake valve stays open for 74* after bottom dead center. It effectively stays open for 32* after BDC at .050"...
Putting these together... The further the intake stays open after BDC, the more compression is bled off. Reversion happens when there is too much overlap at too little flow (read:RPM or boost)... The stock cam doesnt have much total overlap, but has as much dynamic overlap as the R&D (which is negative anyway, meaning both valves overlap for less than 0* of duration when the valves are open to .050" of lift...)... The J2 cam has about as much total overlap as the R&D, but has more dynamic overlap at .050", meaning more chance for reversion at lower RPM's, but when higher RPM's and boost are achieved, there is more cylinder filling, and therefore more power.... This just covers the intake side though, there is more as far as the exhaust sides are concerned...
As far as the TYP4 cam is concerned, the best I can do with the knowledge I have of it, is that it increases lower end cylinder filling by increasing duration on the intake side, but maintaining stockish lifts and timing events as much as possible... This is why it works great in low boost and N/A situations, there is no exhaust pressure inhibiting cylinder filling, and the extra filling it gets from the intake event makes a little more torque lower in the RPM range.
Basically it coems down to where you want your cam to perform... The stocker is a good all around cam for everyhing, the TYP4 is better than the stocker at low RPM, the R&D is great for engines that spend their time boosting 10-20psi while doing work, and the J2 is great for WOT/Higher RPM/higher boost situations while doing work... They all have their place...
#17
12-31-2014, 12:28 AM
#18
12-31-2014, 07:40 AM
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Basically it coems down to where you want your cam to perform... The stocker is a good all around cam for everyhing, the TYP4 is better than the stocker at low RPM, the R&D is great for engines that spend their time boosting 10-20psi while doing work, and the J2 is great for WOT/Higher RPM/higher boost situations while doing work... They all have their place...
the J2 was a flop.it should go where it belongs.in the round file.no idi should ever sport such a grind.the exception could be the track,but then ask what are you doing with an idi at the track? (besides loosing) lol!
HD250....I understand what you are saying about different can profiles. I have a hot cam profile in my track car that causes me to lose torque down low as a trade off for higher rpm power.
You mentioned the torque cam. Were you referancing the type4 torque cam. My understanding of its profile is that it increases low end torque in NA engines to help towing characteristics. Am I mistaken? Looking at dyno graphs of the torque cam it looks like it peaks earlier than the R&D cams.
Can you expand on this?
You mentioned the torque cam. Were you referancing the type4 torque cam. My understanding of its profile is that it increases low end torque in NA engines to help towing characteristics. Am I mistaken? Looking at dyno graphs of the torque cam it looks like it peaks earlier than the R&D cams.
Can you expand on this?
one of the big advantage of the idi is it's high compression.this gives a superior bottom end not found in psd's.by frigging this up,your removing a great advantage.if you must,you must depending on your build sure.but why hurt your bottom end and mid range unless you have too? who boosts over 10 psi all the time? your truck would need to be hooked to a trailer full time.otherwise your going to be out of the power-band of the grind 95% of the time.
this is why calling the grind "stage 1" was a poor choice is all.im not trying to say someones intent was misleading.again it's just my opinion.doesn't mean im right.he designed the grind,he can call it what he wants lol.
this is the one where all the cams are in it (this was my first run, the big blue line is because i held the same rpm to long before i backed out and it kept sending data)
<a href="http://s1095.photobucket.com/albums/i463/91dirtydiesel/?action=view&current=dynocams.jpg" target="_blank"><img src="http://i1095.photobucket.com/albums/i463/91dirtydiesel/dynocams.jpg" border="0" alt="Photobucket"></a>
<a href="http://s1095.photobucket.com/albums/i463/91dirtydiesel/?action=view&current=dynocams.jpg" target="_blank"><img src="http://i1095.photobucket.com/albums/i463/91dirtydiesel/dynocams.jpg" border="0" alt="Photobucket"></a>
#19
12-31-2014, 02:14 PM
I still dont understand where youre trying to go with this..? The stage 1 is named stage 1 because it is a great mild cam for warmer than stock applications(aka turbo) It just so happens that it shines as a good cam for high output applications as well, that we know of anyway, there is very little data to compare with the J2, and there is no other "hot" cam grinds out there -yet.
500+ lb-ft with 90cc at 1700 and 700+ lb-ft just over 1600rpm with a peak horsepower rpm of 2800 doesnt exactly scream "high rpm race engine only" All that was with a single S366 turbo which... is huge and one can only conclude that a smaller sized turbo would only push the power LOWER in the power band due to spooling faster... I dont want a pissing match with you, agian, but sounds like youve been in the kool-aid on the "other site" again.
In summary, the stage 1 is a perfect mild grind for turbo applications, its clean, it lights fast, produces excellent low-midrange power. aka, everything a stage 1 should do.
This isnt a popularity contest, its science. Forced induction engines have different needs from their cam than a naturally aspirated engine. So i still maintain that the torque cam is a great NA cam, and a no brainer if staying NA, its not a bad cam for a turbo engine, the stage 1 simply is better, as it was designed to be, on a turbo engine.
500+ lb-ft with 90cc at 1700 and 700+ lb-ft just over 1600rpm with a peak horsepower rpm of 2800 doesnt exactly scream "high rpm race engine only" All that was with a single S366 turbo which... is huge and one can only conclude that a smaller sized turbo would only push the power LOWER in the power band due to spooling faster... I dont want a pissing match with you, agian, but sounds like youve been in the kool-aid on the "other site" again.
In summary, the stage 1 is a perfect mild grind for turbo applications, its clean, it lights fast, produces excellent low-midrange power. aka, everything a stage 1 should do.
This isnt a popularity contest, its science. Forced induction engines have different needs from their cam than a naturally aspirated engine. So i still maintain that the torque cam is a great NA cam, and a no brainer if staying NA, its not a bad cam for a turbo engine, the stage 1 simply is better, as it was designed to be, on a turbo engine.
#20
12-31-2014, 03:54 PM
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nor do i with you.what kind of comment was that? i respect your comment and views (save for this childish one.) though we disagree and or have different opinions doesn't make us enemies friend.im not trying to change your mind about anything.im simply sharing my opinion.that's what we welcome here.right wrong or indifferent.happy new year! 
edit.i recall your "again" comment part now.not the first time you've been immature with your comments.hairyboxnoogle your now on my ignore list.if my views,opinions,expressions,comments offend or bother you,feel free to add me to your ignore list as well.this way i wont see your comments and if you don't want to see mine the choice is yours.just know i'll no longer be able to view posts by you.
goodbye.
edit.i recall your "again" comment part now.not the first time you've been immature with your comments.hairyboxnoogle your now on my ignore list.if my views,opinions,expressions,comments offend or bother you,feel free to add me to your ignore list as well.this way i wont see your comments and if you don't want to see mine the choice is yours.just know i'll no longer be able to view posts by you.
goodbye.
#21
01-01-2015, 03:46 PM
#22
01-02-2015, 02:37 AM
While I don't try to deny that lowering compression "costs" power, I would say that the loss is being greatly exaggerated here. Justin put his stage 1 in an NA engine and it performed just fine. It did not kill the bottom end of the power band and turn it into a dog. Whatever the "cost" of compression bleeding, it is a small pice of admission to gain great benefits on cylinder filling while boosting. You won't get 10-20 psi off idle, but you will get it quite easily under load while accelerating through the gears or pulling grades with an upgraded IP and turbo. The boost comes from fuel being burned, and the lower the IP output the more rpm's are needed to see that boost. Higher fueled engines will spool the turbo to those pressures much earlier in the rpm spectrum. I seriously don't think Justin was trying to imply that his cam was for people who want to drive 100 mph and boost 10-20 psi constantly while cruising. I think the point is that it really shines doing work, under load, and allowing the turbo to boost and provide the power when it is needed. Higher compression does mean more cylinder pressure, and therefore more power, but when lowering compression a little allows you to cram more oxygen into the cylinders and burn more fuel, the power increase is huge. I think we agree on this more than it may appear because of the "stage 1" semantics. If I were building a NA or kit turbo'd engine wastegated at 7psi or 9psi I would totally call Russ and get the Type 4 cam. But with a 90cc or better IP and upgraded turbo in a truck intended to accelerate and do work at highway speeds I think the stage 1 will be a really inteligent compromise as far as cam designs go, since we don't have variable valve timing and other modern day engineering tricks under the hood. I'm fixing to find out I guess... since I bought a stage 1 for my build. 
#23
01-02-2015, 07:59 AM
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While I don't try to deny that lowering compression "costs" power, I would say that the loss is being greatly exaggerated here. Justin put his stage 1 in an NA engine and it performed just fine. It did not kill the bottom end of the power band and turn it into a dog. Whatever the "cost" of compression bleeding, it is a small pice of admission to gain great benefits on cylinder filling while boosting. You won't get 10-20 psi off idle, but you will get it quite easily under load while accelerating through the gears or pulling grades with an upgraded IP and turbo. The boost comes from fuel being burned, and the lower the IP output the more rpm's are needed to see that boost. Higher fueled engines will spool the turbo to those pressures much earlier in the rpm spectrum. I seriously don't think Justin was trying to imply that his cam was for people who want to drive 100 mph and boost 10-20 psi constantly while cruising. I think the point is that it really shines doing work, under load, and allowing the turbo to boost and provide the power when it is needed. Higher compression does mean more cylinder pressure, and therefore more power, but when lowering compression a little allows you to cram more oxygen into the cylinders and burn more fuel, the power increase is huge. I think we agree on this more than it may appear because of the "stage 1" semantics. If I were building a NA or kit turbo'd engine wastegated at 7psi or 9psi I would totally call Russ and get the Type 4 cam. But with a 90cc or better IP and upgraded turbo in a truck intended to accelerate and do work at highway speeds I think the stage 1 will be a really inteligent compromise as far as cam designs go, since we don't have variable valve timing and other modern day engineering tricks under the hood. I'm fixing to find out I guess... since I bought a stage 1 for my build.
#24
01-04-2015, 01:24 PM
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Well this got a lot more attention than I thought it would 
Anyway thanks for all the replies, gives me a little to think about and look forward to. I don't plan on putting huge amounts of money into this engine. If I'm gunna go all out it'll be on a 12 valve swap. Thanks again everybody!
-Kolby
Anyway thanks for all the replies, gives me a little to think about and look forward to. I don't plan on putting huge amounts of money into this engine. If I'm gunna go all out it'll be on a 12 valve swap. Thanks again everybody!-Kolby
#25
01-06-2015, 02:12 AM
Posting Guru
the lower the CR the more CC's of air/fuel in the chamber at and any given boost psi. as any proper turbo install will fill that space. pressure's increases and power increases. low CR is more likely affect Cold start, properly working GPs in the Idi, make this less of a problem. IMO if you want 300+ hp you will need the stage1 as it moves more air thru the engine it will push a bigger wheel too..as for stockish fuel, stockish turbo's I agree with 250 gains would not be nominal free flowing air box, and exhausts go with out saying..when they designed the 7.3 they did the best they could with what they had. at the time. every thing is a trade off, torque for Horsepower, fuel economy for work performed. when I build a 7.3 for my self it will have the stage 1.
#26
01-22-2015, 10:03 PM
Postmaster
....keep in mind,the "stage 1 cam" will cost you power over oem and for sure the torque cam in the powerband where you'll be spending 95% of your time on the street.....unless you've got an f-super duty.then it's probably a match made in heaven at 50+ mph with a od trans.
imho you don't want a "stage 1 cam" but it's great to have available for those who might need one.i think the grind Russ sells should be the one titled stage 1 with Justin's labeled stage 3.calling an upper rpm power band grind a stage 1 is misleading.
I see what you did there...
Care to substantiate those claims?...
My stage one has made more torque at 1700RPM with similar fueling than the torque cam has... Why is that considered stage 3?
Hate to break it to you, but even I consider myself a friend of Typ4's, and I will tell you that the Torque cam is old news... I can tell you every event on that cam, and why it is subpar to the stage 1, with numbers and proof.... And as well versed as you are in the IDI's, Id hope that you could accept the facts. Sometimes you just have to understand, that regardless of bias to a particular pathway in a platform you are, when you are faced with raw numbers in raw form, as honest as it gets, you should probably respect them, or at least prove them wrong.
#27
01-22-2015, 10:13 PM
Speaking of real numbers... what cam performs best from idle(800RPM) to 1400RPM, torque wise? Assuming a turboed engine, but at effectively 0 PSI(due to the turbo not spooling until above that)?
Is the stock cam best in this area? R&D Stage 1? Typ4?
I'd really like to see some numbers. max HP and max torque is great, if you're at that RPM. But low-end torque = easier idle-starts, less revving. Which is why I'm curious.
Is the stock cam best in this area? R&D Stage 1? Typ4?
I'd really like to see some numbers. max HP and max torque is great, if you're at that RPM. But low-end torque = easier idle-starts, less revving. Which is why I'm curious.
#28
01-22-2015, 10:13 PM
Postmaster
he's honest and open.read that ^ he's right on.i don't mean to imply he's trying to be misleading.it's just my opinion the name of his cam grind is because of where it's designed to provide the power.
the J2 was a flop.it should go where it belongs.in the round file.no idi should ever sport such a grind.the exception could be the track,but then ask what are you doing with an idi at the track? (besides loosing) lol!
yes the torque cam.Justin clearly explains the cams and how they work.this is why i say calling it "stage 1" is misleading.how do you get boost of 10-20 psi? you don't get it off idle.you get it in the upper rpm band.like i said,for a street cam your going to have less power 95% of the time where your driving rpm is.the exception is a motor home or f450 with low gear raito's......well ok or a c6 trans i guess.for those with od trans and 3.55's or even 4.10's this is going to reduce your take off and your cruising rpm power.yes.that's right.it will reduce the power of your od gear.that would suck unless your driving on the hwy going fast enough to be up in the 2k rpm range.otherwise,you'll have less power while cruising here than with a oem cam.
one of the big advantage of the idi is it's high compression.this gives a superior bottom end not found in psd's.by frigging this up,your removing a great advantage.if you must,you must depending on your build sure.but why hurt your bottom end and mid range unless you have too? who boosts over 10 psi all the time? your truck would need to be hooked to a trailer full time.otherwise your going to be out of the power-band of the grind 95% of the time.
this is why calling the grind "stage 1" was a poor choice is all.im not trying to say someones intent was misleading.again it's just my opinion.doesn't mean im right.he designed the grind,he can call it what he wants lol.
the J2 was a flop.it should go where it belongs.in the round file.no idi should ever sport such a grind.the exception could be the track,but then ask what are you doing with an idi at the track? (besides loosing) lol!
yes the torque cam.Justin clearly explains the cams and how they work.this is why i say calling it "stage 1" is misleading.how do you get boost of 10-20 psi? you don't get it off idle.you get it in the upper rpm band.like i said,for a street cam your going to have less power 95% of the time where your driving rpm is.the exception is a motor home or f450 with low gear raito's......well ok or a c6 trans i guess.for those with od trans and 3.55's or even 4.10's this is going to reduce your take off and your cruising rpm power.yes.that's right.it will reduce the power of your od gear.that would suck unless your driving on the hwy going fast enough to be up in the 2k rpm range.otherwise,you'll have less power while cruising here than with a oem cam.
one of the big advantage of the idi is it's high compression.this gives a superior bottom end not found in psd's.by frigging this up,your removing a great advantage.if you must,you must depending on your build sure.but why hurt your bottom end and mid range unless you have too? who boosts over 10 psi all the time? your truck would need to be hooked to a trailer full time.otherwise your going to be out of the power-band of the grind 95% of the time.
this is why calling the grind "stage 1" was a poor choice is all.im not trying to say someones intent was misleading.again it's just my opinion.doesn't mean im right.he designed the grind,he can call it what he wants lol.
#29
01-22-2015, 10:23 PM
Postmaster
Speaking of real numbers... what cam performs best from idle(800RPM) to 1400RPM, torque wise? Assuming a turboed engine, but at effectively 0 PSI(due to the turbo not spooling until above that)?
Is the stock cam best in this area? R&D Stage 1? Typ4?
I'd really like to see some numbers. max HP and max torque is great, if you're at that RPM. But low-end torque = easier idle-starts, less revving. Which is why I'm curious.
Is the stock cam best in this area? R&D Stage 1? Typ4?
I'd really like to see some numbers. max HP and max torque is great, if you're at that RPM. But low-end torque = easier idle-starts, less revving. Which is why I'm curious.
I can say that every cam has peaked HP at 2800RPM, which is resultant of the pump, but the Torque peak is totally represented by the cam, AND the turbo selection. The Torque Cam has made peak HP at 1800RPM on Russ's truck, I was an in person witness. Russ is running one of his 60-1/Stock hybrids and made 217/264 at the wheels. The stage one has made a torque peak of 1700 with an HX35, and 2200 with an S366. 483/528 respectively. The stock cam and the Torque cam have issues with lift, both are less than .380". The torque cam has lots more duration, more than the stage 1, but its events are very close to the stock cam, just bigger lobes. The stage one has the correct opening and closing events, as well as .030" more lift.
Ive posted the graphs, and besides the obvious differences in turbos, its pretty clear the stage 1 has the other cams outdone, unless somebody can put it together better for me...
#30
01-22-2015, 10:26 PM
Postmaster
Literally, by my best calculations, even as far as laying out static events in autoCAD for calc purposes.... its about 1 point tops. That wasn't the point of the cam.