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I have another thread going about how I finally got dyno'd at 10psi the other day. I have a d16z6 head at the machine shop being p/p and rebuilt using crower springs/retainers and a stage 3 cam. I also bought a skunk2 IM+TB with plans on building a d16z6 all motor. However, after going to the dyno I think I want to build a serious turbo d16z6 and was wondering if the stage 3 head and skunk2 IM+TB would work ok boosted? is there too much overlap on a crower3 cam?
 

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crower makes a stage 2 turbo cam

stage 3 NA would have too much lift and duration for boost
 

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I know they sell a stage2 turbo cam. The thing I already have the crower valve springs/retainers/stage 3 and it is all going inside my head that is being built now. I don't want to have to rip it out, sell it, and buy a stage 2turbo, and reinstall. It I was doing a n/a build; but, thought it would be cool to have a turbo d16 with a crazy head.

I see other cars that are turbo'd that have crazy cams (5.0 mustangs with mild/radical cams that are turbo'd) and they make power. I know turbo cams are designed different. I was just wondering, thats all.
 

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the boost is going to be blowing a lot of that air/fuel right out of the chamber before it can be compressed and exploded

lots of lift and duration + turbo = no good
 

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the boost is going to be blowing a lot of that air/fuel right out of the chamber before it can be compressed and exploded

lots of lift and duration + turbo = no good
yep....due to the extended overlap the exaust can come back into the cylinders instead of exiting thru the manifold...so yea high duration is def. not good for turbo applications
 

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the boost is going to be blowing a lot of that air/fuel right out of the chamber before it can be compressed and exploded

lots of lift and duration + turbo = no good
correct:TU:

turbo cams have lots of lift and some duration.

i would say go for it if it was just a stage 2 cam, but the stage 3 is so much more radical that i just dont really see it being a good way to go. But again, i dont know because i know jimmyb34 JUST installed his turbo setup on his motor and he is running an exospeed stage 3 cam. he says it runs great, so maybe you should talk to him. Best way to find out is talk to the ones that know from expirience.

good luck:TU:
 

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If you already got the stage 3, rock it. No one on this thread has used it for turbo, they are just talkin theory and assumptions.

Heres a couple things I dug up.

NA cams rock w/ FI! Bottom line.
It is, but I have tried them and NA cams walk all over turbo cams, and stockies unless you pay high dollars for custom cam w/ specific build and kit..
Apparantly this guy has used it.
 

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If you already got the stage 3, rock it. No one on this thread has used it for turbo, they are just talkin theory and assumptions.
thats why i said to talk to jimmyb34........but i agree. dont freak out until youve talked to someone who knows!!
 

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Worst Mechanic Ever!
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IIRC, the crower is a bit more radical that the crower, could be wrong, but it's just something to think about.

I'd be curious to see what jimmy says cause I've read mostly that stage 3 cams + turbo = bad things are gonna happen, kinda curious to see what the real world result are...
 

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ive had no trouble with running a stag3 and boost.. top end is like a motherfucker.. im sure the cam has something to do with that.. i havent got it on a dyno or anything to compare to a stocker but i dont see it being a problem in my case at all
fyi the guy quoted above (berettagtz) is who i bought this cam from.. its the same cam that he had in his motor running a 12.9 boosted in an eg hatch with just a t3 42/48....
 

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cams are a waste of money. stock is usually best if boosted. spend the money on the block.
 

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If you already got the stage 3, rock it. No one on this thread has used it for turbo, they are just talkin theory and assumptions.
QFT.

Think about it. More air = more air. How about b series cams? Which cam is considered the best NA stock cam?? b16. Which is considered the best turbo cam?? b16.

Search HT. There was a thread about this with dyno's and everything a while back.

I'd personally (not from experience, though) go stage 2 NA over stage 2 turbo cam, but I don't know about the stage 3 NA cam.

It depends on the tuner. Stage 3 = have to tune it to get it to idle. Is he good enough to tune the cam AND turbo? Shit tuner + stage 3 cam < good tuner +stock cam.
 

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if you search you can find a couple vids of my car... my idle has a fucking lope to it you wouldnt believe from a turbo car imo...

and you say cams are a waste.... have you ever had a cammed car, or are you just speaking from what other people say... because when i was na.. the cam was single handedly the best mod i did.. and being turbo now.. i guarantee you my car makes more power than it would with a stock cam..

cams are far from a waste.. look at some of the vitara buikld guys... i think 1 guy picked up somethign liek 40 whp over a stock cam from switching to a 59300 zex cam.. 40 whp isnt much of a waste imo
 

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if you search you can find a couple vids of my car... my idle has a fucking lope to it you wouldnt believe from a turbo car imo...

and you say cams are a waste.... have you ever had a cammed car, or are you just speaking from what other people say... because when i was na.. the cam was single handedly the best mod i did.. and being turbo now.. i guarantee you my car makes more power than it would with a stock cam..

cams are far from a waste.. look at some of the vitara buikld guys... i think 1 guy picked up somethign liek 40 whp over a stock cam from switching to a 59300 zex cam.. 40 whp isnt much of a waste imo
I concur! he is right.....Cams are not a waste ladies.......
 

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put in ur Crower 3...Tune it and let us know....at least with a built head, you can rev it a lil more safely.
 

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cams are only good if your car is tuned for it. most people don't realize that sometimes the biggest power gain you can get out of your engine is all in the tuning and not just slapping stuff into the engine and expecting big gains.

btw, have fun installing the titanium retainers and springs. they were a b*tch to install.
 

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Turbo and valve overlap
by date / by score





Dustin
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[1] 14:49:05, Mar 26th 2007






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Back in the day, the "pseudo-expert" opinion was that cam/valve overlap was "bad" with a turbo setup, as it would "waste" your boost. So we had people pulling their CTR cams and putting in auto B16 cams to "save" all that precious boost.

Today, I think the scene has learned a lot, and I'm certain we've moved past this point. People have been making lots of power with overlap in vtec.

Is the a consensus today regarding cam overlap? Clearly it depends a lot on the specifics of the setup itself, but it seems there is power and driveability to be had with some overlap. Certainly overlap helps spool larger turbos, and helps evacuate the combustion chamber.

Anyone with real-life experience have any input? It would be great if we could all understand the theory behind this historically-controversial topic.






Tony1
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[2] 07:57:07, Mar 27th 2007






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That main thing that's changed from the old way of thinking is exhaust manifold design and turbochargers. Back in the day, we were primarily dealing with cast exhaust manifolds and "small" (by todays standards) turbochargers. This resulted in much higher exhaust backpressure ratios than we are usually dealing with today, with more efficient turbos and exhaust manifolds. "big" cams will not work well with high exhaust backpressure ratios because you get a lot of exhaust reversion during overlap when the exhaust pressure is higher than the intake pressure. This reversion means old exhaust gas stays in the cylinder rather than taking in more fresh air, thus loosing power. All the engine knows is the pressure ratio across the cylinder. You get the exhaust backpressure low enough, and the engine responds much like a naturally aspirated engine again, and big cams are definitely beneficial.






Expert
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[3] 11:25:36, Mar 27th 2007






that was a good and concise explanation by tony1. thanks!

big cams for a turbo will ultimately still be smaller than the big cams for NA apps.






Expert
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[4] 15:23:45, Mar 27th 2007






My exact sentiments as well.






Tony1
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[5] 11:58:52, Mar 29th 2007






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I guess that's it? lol






xtrac1
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[6] 13:35:16, Mar 29th 2007






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Another benefit is the assist in evacuation of all the burnt or unburnt gases out of the chamber to make room for the next charge so that the entire (or almost) mixture is fresh.






Dustin
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[7] 16:24:57, Mar 29th 2007






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Tony1
I guess that's it? lol


You had such a great response you left me speechless :)

Great answer, definitely clarifies what's really going on.






Overkill
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[8] 08:49:36, Mar 30th 2007






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How does one judge if their exhaust back pressure is low enough?






Dustin
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[9] 14:40:01, Mar 30th 2007






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Does anyone have any thoughts on what the duration should be?






Tony1
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[10] 14:55:14, Mar 30th 2007






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You determine your pressure ratios by datalogging MAP and EMAP (intake manifold pressure and exhaust manifold pressure). As far as picking a cam, that's not nearly as easy. lol A LOT of that is trial and error, it's not as easy as picking a duration you want.
 

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If you already got the stage 3, rock it. No one on this thread has used it for turbo, they are just talkin theory and assumptions.

Heres a couple things I dug up.





Apparantly this guy has used it.
this guy also posted this the other day in the forsale section.

Stage 3 has too much overlap for boost...Coming from someone who tried and failed :)
 
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