View Full Version : Jp4 turbo cams
ababaz
26th February 2017, 19:58
Hello
I would like to know what are the benefits of catcams 1322708 for jp4 turbo build? (Catcams stage 2 turbo jp4 cams)
Does they improve spool rpm and allow to make more power at the same pressure ? How many hp then?
Ppl told me that i should stick with j4 cams for my hp goal..
I aim 350/400hp
Full forged jp4 iapel pistons and k1 rods
Brand new head 0km!!!
Upgraded springs and retainers
Supertech valves
Custom intake mani
650cc injectors
Big ic (13liters)
2871 ar.64
Megasquirt
I ask about the cams because i can get em for a really cheap price so is it worth ?
Thanks
ababaz
26th February 2017, 20:36
https://image.noelshack.com/minis/2017/08/1488141072-1322708.png (https://www.noelshack.com/2017-08-1488141072-1322708.jpg)
axsaxoman
27th February 2017, 10:17
your main problem will not be a dyno max bhp figure ,but drivability
and wihtout a complicated boost control system it will come on like hammer when it spools up --common figures i have seen on dyno for a gt28 are
3000rpm 80/90bhp @wheels
3800rpm 180bhp @wheels
a very big hump once it reachs the spool up point
consider seriously a lower poundage actuator(4lbs) and then 4 way boost control via PWM device
with right set up you can then decide boost level at any rpm and /or any road speed with right inputs
If its for drag racing then just get used to it
-fast road /track driving you want more control
the bottom line is that it is too big and too old technology for a 1.6 to be nice to drive
ababaz
27th February 2017, 13:04
Hello thanks you for the advices john. I might get a boost controller and we gonna plan on a boost by gear setup too. But i would like to know more about the turbo cams, does they provide greater hp than jp4 ou j4 cams at same boost pressure ? Does they reduce the rmp spool speed either? I can get em for a good price as i said so thats why i really want to know if they are worth based on my setup and goals obviously.
axsaxoman
28th February 2017, 08:52
turbo type and choice of input and out put turbines is only thing that will make a real difference to spool up rpm .
turbo controller can only work above the actuator spring value --that is why you need to fit very low one to get sensible control
If you looking for spool up at 2k-2.5k --you got wrong turbo
your goals ? 350 -400 --a very wide target --350 you could get there or very close with an evo turbo which would spool up under 2k
what are you using car for ?
ababaz
28th February 2017, 11:30
Car is for street use (not daily tough) maybe 4 times a week. Turbo is 2871 ar64 turbine and ar50 compressor
I dont really want to spool faster but reallywant to know how much hp i could get with the turbo cams. If around 20/30hp..or just 10hp... i know its depends on mapping too
thx
axsaxoman
28th February 2017, 15:59
Car is for street use (not daily tough) maybe 4 times a week. Turbo is 2871 ar64 turbine and ar50 compressor
I dont really want to spool faster but reallywant to know how much hp i could get with the turbo cams. If around 20/30hp..or just 10hp... i know its depends on mapping too
thx
think you missing the point --you cannot control the amount of boost +therefore power until it has reached rpm where it is spooled up fully+ actuator spring value has been reached ,eg that is when your boost control device can start working
which I guessing will be around 3800rpm
I cannot say , as I have no experience with those cams --ask cat cams directly they make them
Chipwizards
28th February 2017, 20:50
Cams that give better VE at low revs will help spool because the exhaust mass flow is greater for a given rpm.
Bigger cams won't help with spool, most definitely not.
If the car is for road use then aim for much less power, there's zero point making more power than your chassis and contact patches can manage, your car WILL be slower with too much power, as well as being bloody awful to drive.
If you want to just talk bullshit about how much power you've got but have a car that's totally shit to actually drive then go ahead, fit big cams and a turbo that's too big.
ababaz
1st March 2017, 08:52
Hello.
i want the car to be effective, dont really care if i make big hp..(i just tought that 350/400 wouldbe fine but it seems to.be too much...
i just hope the lsd will do is job. Ill ask catcams.about the cams gain (if there is one)
I want to find the right spot...when the tires start to spin because of too much power..because i want it to be effective.
I undestund both of your points obviously, thank again
Making.big hp dosent mean goin fast of course
axsaxoman
1st March 2017, 09:15
If you asked me a direct question about what cams to fit bearing in mind a turbo should be about wide range power, --then probably the std tu5jp4 cams+head --206 .etc .les valve overlap so good low sped =idle as well-which std206car makes 110bhp at 5800--saxo vts cams make 120 at 6800 and they don,t make 110bhp at 5800rpm maybe 100bhp tops --so for a sensibly matched turbo and control that would be my starting point boost will stretch power to 6500-7000 no problem and that really is enough rpm for turbo --bearing mind the be3 box you have could be high ratio anyway
have you worked out max speeds with the be ratios? ,some at 7k will be giving you 160mph +
don,t get upset at what I am saying-just think about it.
even with s/c i never go really wild cams ,but never turbo cams ,s/c engine is like a combination of n/a +boost as far as power curve goes
so many ways to do it --but you start with a plan and build to your target of power and where you want it -not the other way round
my own s/c race car I stopped at 290@wheels+ fragile for continuos running --cos it was getting undrivable on a track and more power is for drag and short runs only-too many heat problems in block otherwise
I had it giving 400+at flywheel --but would only last about 20 mins before block distorted and damaged pistons
for drag would have lasted no problem --but not for 45min+ races at full power
you want 400/500+reliable --you need to start with ds3 engine wet liners ==but thats a whole development job --very little on std engine would be left unchanged
looked at it, did a few tests ,but never took it any further as no market for it with costs involved
axsaxoman
1st March 2017, 09:18
Hello.
i want the car to be effective, dont really care if i make big hp..(i just tought that 350/400 wouldbe fine but it seems to.be too much...
i just hope the lsd will do is job. Ill ask catcams.about the cams gain (if there is one)
I want to find the right spot...when the tires start to spin because of too much power..because i want it to be effective.
I undestund both of your points obviously, thank again
Making.big hp dosent mean goin fast of course
if you are serious- dump that turbo and find a good std or stge 1 evo unit -- half the physical size no it will not fit on same manifold it is wrong way round -- but you could modify manifold to fit.
don,t take my word find someone with an evo and put in top gear flatten throttle at 1800-2k and watch boost-- it will be 1 bar or very close --friend has a tomi evo6 and thats what that does-- so you are 1600cc not 2000c --so it might be 2500-2800rpm where you 1bar --still plenty
ababaz
1st March 2017, 14:44
Hello john. I did the gearbox myself..be4 from picasso with 206rc ratios and 19x72 fd with partner ushaia lsd.. on my calculations it makes 240kmh at 7600rpm on 195 45"15. Its going on a ax verry stripped btw.
Ill see for a evo turbo, its just a flange job btw, nothing impossible.
Forgot to mention..car will be for short runs use too
axsaxoman
2nd March 2017, 08:46
Hello john. I did the gearbox myself..be4 from picasso with 206rc ratios and 19x72 fd with partner ushaia lsd.. on my calculations it makes 240kmh at 7600rpm on 195 45"15. Its going on a ax verry stripped btw.
Ill see for a evo turbo, its just a flange job btw, nothing impossible.
Forgot to mention..car will be for short runs use too
if going in an AX even more reason to fit smaller turbo --alot less space than a saxo under bonnet as well as 20% lighter car as std -
-still think it will be wheel-spin city without very good boost control -
-and don,t fit a super light flywheel --a bit of mass to smooth the engine acceleration out will be an advantage and even 300bhp+ in an ax will be a big handful - never mind the 400 your were thnking of
you can always email me direct gmcmotorsportuk@aol.com--
If you re thinking your ideas maybe some other things I could suggest that you might want to change to make more space under bonnet
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