Turbo and cams...

[STUNNAH]

Anyone have an opinion on the topic of a turbo with cams...I got a few responses on other sites that say this is a no, no...
I want to swap the exhaust cam for an intake to pick up any lost hp from the lower compression...

Help a brother out...



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[Rosco]

Don’t know if this helps but I recall reading in a mag that stock cams were often better for turbo's when on boost.
I forget the exact explanation but it had something to do with excessive overlap on hotter cams not being too great for the set-up.

I assume it would depend on the grind of the originals as to wether you would get much improvement.

Cheers
Ross

 

[GIXERHP]

That should be fine, The biggist advantage will be you'll have adjustabity in your cam line. You should try to do the cam and adj spockets, before the turbo. Just so the tuning issues would be gone, if posible!

 

[mountainmotor]

Anyone have in opinion on the topic of a turbo with cams...I got a few responses on other sites that say this is a no, no...
I want to swap the exhaust cam for an intake to pick up any lost hp from the lower compression...

Usually first thing I would ask before helping in a topic like this is :

What are all your mods and how will the engine be used ?

But , the Busa already has turbo type cams in it . Modern 4 valve bike engines use more intake duration than on the exhaust and thats what you get when you buy a turbo grind for a V-8 Chevy or a 2 valve kawasaki or Suzuki .
Cams like this will spool the turbo faster for quicker boost and response and has potential to reduce turbo lag and give strong upper midrange and top-end HP as boost goes up because of trapping cylinder pressure .

Your post suggests you might be running a spacer plate . If so , both cams will be grossly advanced . If any head milling or block decking has been done cam timing will be considerably less than optimum .

Stock cam timing gets the job done on engines thats never been apart or machined .... it's still less than optimum though .

Suggest using the stock cams set on 104-104 or use the intake on exhaust with large CC high compression/boost motors . Give me more info and the baseline settings might be subject for change .

 

[STUNNAH]

Here's what I'm thinking if its to much let me know...

To compliment the Velocity Stage 1 Street system Garrett T28...System capable of supporting 8pds of boost @ approx. 285HP...No change/upgrade to fueling system...

JE Turbo Pistons
.080 base plate
Intake cam for exhaust swap
Adj. cam sprockets
Cam tensioner
Cylinder studs
Main bearing studs
Falicon rods
High volume oil gear
Oil pan baffle
Crank sent to Falicon for some magic

Appears to be alot more than I may need but attempting to build a motor that will last indefinitely...

Most of the items are in should have the rest by the end of the week...

 

[NearDeath]

Here's what I'm thinking if its to much let me know...

To compliment the Velocity Stage 1 Street system Garrett T28...System capable of supporting 8pds of boost @ approx. 285HP...No change/upgrade to fueling system...

JE Turbo Pistons
.080 base plate
Intake cam for exhaust swap
Adj. cam sprockets
Cam tensioner
Cylinder studs
Main bearing studs
Falicon rods
High volume oil gear
Oil pan baffle
Crank sent to Falicon for some magic

Appears to be alot more than I may need but attempting to build a motor that will last indefinitely...

Most of the items are in should have the rest by the end of the week...

Yup, you can do it... My buddy that did the Velocity race had KEPT his intake for exhaust side on the bike... The adjustable Cam sprockets that you get from APE, will have SPECIFIC instructions for setting with intake/exhaust cam scenario...

If you need help and a little bit more info... Ping Badazzbusa on this site... If you don't get a response, I can call him...

CLoud

 

[mountainmotor]

STUNNAH ,

With that small turbo and the relative low boost you will have alot more torque below 4500 rpm if you stay with the stock cams and run them at 105-105 or 106-106 . You can even run up to 108 if you want .

Like around 15 more  ft lbs vs using the intake on exhaust then having to spread the lobe center angles way apart to keep reversion in check and to trap cylinder pressure .

If it's a street bike I really think you'll like the stock cams better when rolling on the throttle from down low .

If you worried about the static compression you have lowered , just remember boost is compression so for an engine to pull hard as stock down low , cams will need be near stock duration and overlap at low boost .

Running overlap for stock cams is 62 . Intake - Intake is 96 degree's of running overlap when set on 106 .

Hope this helps .

 

[STUNNAH]

STUNNAH ,

With that small turbo and the relative low boost you will have alot more torque below 4500 rpm if you stay with the stock cams and run them at 105-105 or 106-106 . You can even run up to 108 if you want .

Like around 15 more  ft lbs vs using the intake on exhaust then having to spread the lobe center angles way apart to keep reversion in check and to trap cylinder pressure .

If it's a street bike I really think you'll like the stock cams better when rolling on the throttle from down low .

If you worried about the static compression you have lowered , just remember boost is compression so for an engine to pull hard as stock down low , cams will need be near stock duration and overlap at low boost .

Running overlap for stock cams is 62 . Intake - Intake is 96 degree's of running overlap when set on 106 .

Hope this helps .

Your response is a bit technical...But I think what your saying is leave the cams stock...

 

[STUNNAH]

STUNNAH ,

With that small turbo and the relative low boost you will have alot more torque below 4500 rpm if you stay with the stock cams and run them at 105-105 or 106-106 . You can even run up to 108 if you want .

Like around 15 more  ft lbs vs using the intake on exhaust then having to spread the lobe center angles way apart to keep reversion in check and to trap cylinder pressure .

If it's a street bike I really think you'll like the stock cams better when rolling on the throttle from down low .

If you worried about the static compression you have lowered , just remember boost is compression so for an engine to pull hard as stock down low , cams will need be near stock duration and overlap at low boost .

Running overlap for stock cams is 62 . Intake - Intake is 96 degree's of running overlap when set on 106 .

Hope this helps .

Your response is a bit technical...But I think what your saying is leave the cams stock...

By the way...THANKS...

 

[NearDeath]

STUNNAH ,

With that small turbo and the relative low boost you will have alot more torque below 4500 rpm if you stay with the stock cams and run them at 105-105 or 106-106 . You can even run up to 108 if you want .

Like around 15 more  ft lbs vs using the intake on exhaust then having to spread the lobe center angles way apart to keep reversion in check and to trap cylinder pressure .

If it's a street bike I really think you'll like the stock cams better when rolling on the throttle from down low .

If you worried about the static compression you have lowered , just remember boost is compression so for an engine to pull hard as stock down low , cams will need be near stock duration and overlap at low boost .

Running overlap for stock cams is 62 . Intake - Intake is 96 degree's of running overlap when set on 106 .

Hope this helps .

Your response is a bit technical...But I think what your saying is leave the cams stock...

My mechanic already had done his previously before doing the turbo setup and didn't want to go back to stock, so we made his work with his velocity stage race... The consensus was that you don't need to do CAMS for turbo, you aren't going to get any real extra power out of it... If you want more power, kick up more boost...

You can do it though if you want; it will work...

 

[Uncle Bob]

if you want the best power, 220-230 duration at .050" lift is a good duration to look for. How you degree the cams will change what you're aiming for.

Stock is probably a very good option because its probably very close to the above numbers. But you should degree the cams regardless.

 

[fstbusa]

i've heard low hp turbos should keep stock cams.



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[STUNNAH]

So there is pretty much a consensus to remain stock which I have no problem with...