Really low vac with 274 cams

[dsmgsx98]

So I installed some Dsm graveyard 274 reground cams strait up and trying to figure out why the my vacuum is at -8 at 900rpm. I thought they would still have a vac of around -12 to -14 can someone that has these cams help me out

 

[dsmgsx98]

I don't even have these cams and i want to know how they perform with the adjustments ! good thread!

I know right, I am so glad I asked about the cams ... This is what its about right here and for army777's help I give him more Rep points, thanks again

P.s...I bought some unorthodox cam gears they should be here Wen so I can test more too!!

 

[Sandman817]

a little side track from the vacuum problem, but is anyone running these cams with a big 16g?

 

[dsmarmy777gst]

im as anxious as you guys. TOMORROW we will find out I should have it ready before noon... unless something else gets in the way but lets hope not. I'm running these cams in my 2.4 with an hx35. I wish there was a dyno around. I'd just go there to see whats really going on. I'm installing a JMF race intake manifold later this month, I think it'll turn out to be a really good setup!

 

[dsmgsx98]

a little side track from the vacuum problem, but is anyone running these cams with a big 16g?

I am running them with a Evo 3 16g

 

[hurricanecris24]

I am running them with a Evo 3 16g

cams seems a bit overkill for your setup since its your street car

 

[dsmgsx98]

Well I was told they were 272s but when I got them they where 274s so I am working with these.....Ann's why do you think they are over kill for a street car cause I believe these came adjusted with an hx35 would be a bad ass street setup

 

[hurricanecris24]

Well I was told they were 272s but when I got them they where 274s so I am working with these.....Ann's why do you think they are over kill for a street car cause I believe these came adjusted with an hx35 would be a bad ass street setup

on a 16g your killing your low and mid range and theres not much gained up top since the 16g dies off and stops making power. hx35 with 274 cams would suit fine, the hx35 is a way different turbo than the 16g. a true twinscroll hx35 with ts manifold would be a nice setup

 

[rx7ttlm]

I don't have THESE cams but I might be able to share some insight. I run FP3 cams which are pretty large and I get about 15-17 in/hg. (IIRC intake is around .410 lift with a shit ton of dwell with steep ramp). Anyhow the key to getting a good idle is first not having vacuum leaks, second sometimes dialing in some dead time, and third proper idle RPM. When I had V2 and the map dropped out it would idle like a pro stock drag car, reallllly lumpy idle and sounded like balls. So dial in your idle rpm to make it idle properly (900 rpm might not cut it), make some changes to the fuel mixture also at idle with dead time (richens the mixture at idle, sometimes big cams like more idle fueling). Oh, if your engine is tired and doesn't have good compression you will also have less vacuum.

 

[dsmgsx98]

on a 16g your killing your low and mid range and theres not much gained up top since the 16g dies off and stops making power. hx35 with 274 cams would suit fine, the hx35 is a way different turbo than the 16g. a true twinscroll hx35 with ts manifold would be a nice setup

You are getting off topic trying to argue a point that has no meaning to me. ...your theory about low and mid range with a 16g is in my opinion wrong because big cams kill that no matter what Turbo you have.... on that note these cams the way they are right now would let this 16g pull all the way to 8k and not stop pulling like stock cams do! So I am going to rock these cams with this 16g untill I get a hx35 with a Bep bolt on housing....thanks for your help

 

[viperlp01]

These are with my 2.3l and SIM 275s.. Lots of good info in hear

http://www.dsmtuners.com/forums/tun...ve-dyno-tuned-your-cam-gears-please-post.html

 

[hurricanecris24]

Get 280 cams they pull even harder on a 16g then.

 

[dsmgsx98]

Lol, get out of my thread please....thanks again for your helpfull info

 

[95gst16g]

I'm running the 272's on a small 16g and its my DD.its not that bad...you lose bottom but so what it pulls way harder up top.

Sent from my DROIDX using Tapatalk

 

[viperlp01]

The thing is no matter what size cam you have it is hard for the 16g to keep up as the rpms rise. If you log in DSMlink with a 16g the airflow starts to fall off around 6k. Unless your 16g is extremely modified with porting and better wastegate setups it is hard to keep flow. With a larger frame turbo the turbo makes peak airflow when you decide to shift. My logs always showed highest airflow in the 7500 rpm range on the HX35/ and HX40. Choosing the right cam is very serious. It effects more than where the powerband is.

 

[dsmarmy777gst]

Okay so I just got back from doing some pulls and according to my butt dyno there was actually some difference. It seemed to pull a lot harder past 4k. I believe Jon from DSMgraveyard said the powerband for these really shines at 4250 or so? If thats the case, then these cams did what they're supposed to. I know its kinda hard to really go off of the feeling, but I guess there is no way to truly tell the amount of gains(if any) unless you get it dynoed.

 

[dsmgsx98]

Okay so I just got back from doing some pulls and according to my butt dyno there was actually some difference. It seemed to pull a lot harder past 4k. I believe Jon from DSMgraveyard said the powerband for these really shines at 4250 or so? If thats the case, then these cams did what they're supposed to. I know its kinda hard to really go off of the feeling, but I guess there is no way to truly tell the amount of gains(if any) unless you get it dynoed.

So how is the low end did it improve? How does your Turbo spool compared to the cams zeroed out?

 

[dsmarmy777gst]

My turbo seems to spool super loud right away. So it must be spooling up a bit faster.

 

[dsmgsx98]

so does it still wanna pull up top like it did before or better now

 

[viperlp01]

Okay so I just got back from doing some pulls and according to my butt dyno there was actually some difference. It seemed to pull a lot harder past 4k. I believe Jon from DSMgraveyard said the powerband for these really shines at 4250 or so? If thats the case, then these cams did what they're supposed to. I know its kinda hard to really go off of the feeling, but I guess there is no way to truly tell the amount of gains(if any) unless you get it dynoed.

Nothing againt Jon at the graveyard but how it the F@ck does he know where they shine at... Of course your car is going to pull harder at 4k. You increased duration and lift. Most bigger turbos are spooling right in that range so thats where the torque is coming in. Give us some datalogs to show improvements in airflow and 70-90 times.

 

[dsmarmy777gst]

I only did a couple pulls but from what I can tell I don't think it made much of a difference. It's always pulled hard. Although I did break the tires loose past 6k in 3rd gear. Not much, but more than normal.

 

[viperlp01]

My turbo seems to spool super loud right away. So it must be spooling up a bit faster.

Again give us some solid or decent proof.

 

[Boomdeeze]

So the overall picture is that after you retarded your exhaust cam 2* and advanced your intake 2*, you increased your vacuum alot and still pull hard. Sounds like it was a success to me!!!

 

[viperlp01]

So the overall picture is that after you retarded your exhaust cam 2* and advanced your intake 2*, you increased your vacuum alot and still pull hard. Sounds like it was a success to me!!!

In the link I posted it shows how we messed around with the settings and found that +2/0 was the majic number where we made the most power at.

 

[Boomdeeze]

In the link I posted it shows how we messed around with the settings and found that +2/0 was the majic number where we made the most power at.

Correct me if im wrong but those were with different cams. Maybe these cams perform the best with different adjustments. And im not saying these perform the best at this setting but I am saying that he seen way better vacuum after he made the adjustments. And the car seems to pull as hard or harder, so he has increased his drivability with the cams.

and you advanced my exhaust cam when I was out there to +2* and my car still had like 6 vacuum idling right around 1k.

 

[dsmgsx98]

In the link I posted it shows how we messed around with the settings and found that +2/0 was the majic number where we made the most power at.

Yeah but what about drivablity on that setting and what does tourqe curve look like