Thumpr cams + lockouts at bama?
05-20-2009, 11:09 AM
#1
5th Gear Member
Thread Starter
Join Date: Mar 2007
Location: Deep in the <3 of Tx
Posts: 3,925
Thumpr cams + lockouts at bama?
I notced over at bama that Doug no longer offers the Comp Cam limiters but instead has BBR lockouts. They are a good amount cheaper than limiters as the limiters are expensive.
I emailed Doug about this as I'm curious the reason behind it and what the pros/cons of lockouts as opposed to limiters.
Brenspeed still offers limiters.
Anyone have any thoughts/opinions?
I emailed Doug about this as I'm curious the reason behind it and what the pros/cons of lockouts as opposed to limiters.
Brenspeed still offers limiters.
Anyone have any thoughts/opinions?
05-20-2009, 11:50 AM
#2
6th Gear Member
Join Date: May 2006
Location: Nicely done
Posts: 11,881
i'm curious what doug says... it might just
be a tuning preference for the various
tuners. one may prefer locking the cams
in a certain position (thus getting rid of
VCT issues), while others may feel mpg
and low end torque considerations, are
worth the added complexity of the tune.
be a tuning preference for the various
tuners. one may prefer locking the cams
in a certain position (thus getting rid of
VCT issues), while others may feel mpg
and low end torque considerations, are
worth the added complexity of the tune.
05-20-2009, 12:21 PM
#3
5th Gear Member
Thread Starter
Join Date: Mar 2007
Location: Deep in the <3 of Tx
Posts: 3,925
Ok so Doug emailed me back. He didn't answer my power difference and MPG difference question (maybe there is no difference?) but he said the reason is the limiters allows the timing to fluctuate at high RPMs.
So I'm still wondering about power differences, MPG difference, and do you install the cam in the fully advanced position or fully retarded position?
Perhaps I'll have to send follow up emails.
So I'm still wondering about power differences, MPG difference, and do you install the cam in the fully advanced position or fully retarded position?
Perhaps I'll have to send follow up emails.
05-20-2009, 01:18 PM
#4
5th Gear Member
Thread Starter
Join Date: Mar 2007
Location: Deep in the <3 of Tx
Posts: 3,925
More infos!
Here's more from Doug:
Here's more from Doug:
VCT is for nothing more than fuel economy and emissions. The Stock ford cams are designed to retard during normal cruising situations to help reduce pumping loss and further increase fuel economy.
Locking out the VCT is best with aftermarket camshafts because the profile design is made for power increases not aimed directly at emissions or mileage. That is why using lockouts on aftermarket camshafts is truly what I feel is best. The dyno results from the Phaser limiters when they were oscillating would should power drops, I actually thought the engine was detonating and losing power but it turned out to be the cam timing was jumping between 6 and 16 degree's because the factory phasers and limiters couldn't keep the timing at a set number at that high of an RPM. With the lock outs you don't have this issue nor do you have the peaks or valleys from the cam timing changing.
Locking out the VCT is best with aftermarket camshafts because the profile design is made for power increases not aimed directly at emissions or mileage. That is why using lockouts on aftermarket camshafts is truly what I feel is best. The dyno results from the Phaser limiters when they were oscillating would should power drops, I actually thought the engine was detonating and losing power but it turned out to be the cam timing was jumping between 6 and 16 degree's because the factory phasers and limiters couldn't keep the timing at a set number at that high of an RPM. With the lock outs you don't have this issue nor do you have the peaks or valleys from the cam timing changing.
05-20-2009, 02:39 PM
#5
6th Gear Member
Join Date: May 2006
Location: Nicely done
Posts: 11,881
good stuff here knight, cam talk is
interesting so keep it coming!
kiss your mileage bye bye with either
configuration and say hi hi to your
favorite gas station.
i love the sound of the exhaust when you
go 1/2 throttle, so my mpg is in the
tank for the foreseeable future.
interesting so keep it coming!
kiss your mileage bye bye with either
configuration and say hi hi to your
favorite gas station.
i love the sound of the exhaust when you
go 1/2 throttle, so my mpg is in the
tank for the foreseeable future.
05-20-2009, 03:16 PM
#6
5th Gear Member
Thread Starter
Join Date: Mar 2007
Location: Deep in the <3 of Tx
Posts: 3,925
Well it doesn't help at all that you have a whipple. 
People usually report 1 to 2 mpg loss, but then again they also have 4.10s which gives pretty high rpms 70 and above. At the same time, city driving is bad for MPG no matter what you do.
People usually report 1 to 2 mpg loss, but then again they also have 4.10s which gives pretty high rpms 70 and above. At the same time, city driving is bad for MPG no matter what you do.
05-20-2009, 06:55 PM
#7
6th Gear Member
Join Date: May 2006
Location: Nicely done
Posts: 11,881
well our mileages will vary greatly, based
on many things of course, so i would just
say if someone is not prepared for 14/20,
then maybe cams are not for them. part
of the fun of having cams, is making them
sing and that requires fuel and in my case,
lots.
on many things of course, so i would just
say if someone is not prepared for 14/20,
then maybe cams are not for them. part
of the fun of having cams, is making them
sing and that requires fuel and in my case,
lots.
05-20-2009, 07:35 PM
#8
5th Gear Member
Join Date: Jul 2007
Location: TX
Posts: 4,897
Thanks sirknight for the camshaft research etc! I've learned a great deal from your inquiries/insights. I still get 19/24 with the hotrods which I find more than acceptable n/a. I'm going to a centrifugal s/c later this summer (once the suspension is perfected) and will swap the hotrods for a more suitable blower cam if its in my best interests.
I still think the hotrods will work pretty good with a centrifugal s/c. The overlap of the hotrods will push a lot of fuel through under boost. With a centri I hope to control the boost a bit more.
I still think the hotrods will work pretty good with a centrifugal s/c. The overlap of the hotrods will push a lot of fuel through under boost. With a centri I hope to control the boost a bit more.
05-20-2009, 07:36 PM
#9
5th Gear Member
Thread Starter
Join Date: Mar 2007
Location: Deep in the <3 of Tx
Posts: 3,925
Yep. I don't mind if I lost a small amount TBH, like 1 or 2 b/c the power increase and sound to me is worth it. I just wouldn't want to lose an unreasonable amount for so little gain. That's my thing. If I lose, it should be reasonable for what caused the loss.
Doug seems to be a big fan of lock outs from what he's been saying to me. But I think I'll stick with the limiters to still get some of the VCT benefit. Comp Cams says good things about it. It may not be a perfect system, but it's more than good enough for me. The bad thing is the limiters are freaking expensive. It's too bad I wasn't skilled in metal work as I'd just make my own. But since I'm not, there's no way I'd trust my own home-grown limiters.
One thing I noticed is that I used to get 1 to 2 MPG better with my Brenspeed tune over my Bama tunes. I read somewhere recently that the Bama tunes are known to be rich for safety. Maybe that's why. Also perhaps that Brenspeed does not do much below 3K rpm (it's actually a little sluggish down there) where you usually are on the street crusing around. They concentrate the efforts > 3K. Perhaps that's another reason why I did better MPG w/ Brenspeed.
I just got my Bama tunes updated for my Kooks that I'll be installing (FINALLY!) during the first weekend of June. I'm thinking I'll pick up a Brenspeed tune or tunes again. It's good to have multiple ones I think.
BTW, is it just me, or was this thread moved. I thought I put it in the V8 section. Oh well. Doesn't really matter.
Doug seems to be a big fan of lock outs from what he's been saying to me. But I think I'll stick with the limiters to still get some of the VCT benefit. Comp Cams says good things about it. It may not be a perfect system, but it's more than good enough for me. The bad thing is the limiters are freaking expensive. It's too bad I wasn't skilled in metal work as I'd just make my own. But since I'm not, there's no way I'd trust my own home-grown limiters.
One thing I noticed is that I used to get 1 to 2 MPG better with my Brenspeed tune over my Bama tunes. I read somewhere recently that the Bama tunes are known to be rich for safety. Maybe that's why. Also perhaps that Brenspeed does not do much below 3K rpm (it's actually a little sluggish down there) where you usually are on the street crusing around. They concentrate the efforts > 3K. Perhaps that's another reason why I did better MPG w/ Brenspeed.
I just got my Bama tunes updated for my Kooks that I'll be installing (FINALLY!) during the first weekend of June. I'm thinking I'll pick up a Brenspeed tune or tunes again. It's good to have multiple ones I think.
BTW, is it just me, or was this thread moved. I thought I put it in the V8 section. Oh well. Doesn't really matter.
05-20-2009, 07:52 PM
#10
5th Gear Member
Join Date: Jul 2007
Location: TX
Posts: 4,897
All I have to say is my car (n/a) would NEVER EVER pull hard to 6k rpm, much less the 6800 that it pulls to now w/ the cams. If I have to give up 1-2-3 mpg to get that kind of high rpm pull then it's worth it to me. And with the 4.10's my shift light is going off at 6800 before I even know it. It revs SO quickly with the driveshaft/longtubes/intake/4.10s. I love this little short stroke smallblock .
.
Last edited by Rubrignitz; 05-20-2009 at 07:54 PM.