Disadvanteges of a higher cam in an uno turbo

Mxgrds

Mxgrds

True Classic
Are there any? I have a installed a racecam (so called) with an adjustable campulley. There is definitely a remarkable improvement in power. It runs and idles very good. I was just wondering if there are disadvantages for maybe the long run? Does it wear more? The reason I ask is, I use this car for holidays to Italy and such. I need a reliable car that can do 3000 km in 2 weeks.
 
You will need to look at the specs for the cam. If it has much overlap on the intake and exhaust lobes, then the boost from the turbo will go out the exhaust valve before it should (i.e. both valves are open at the same time). But I don't think that will harm anything other than the power level. Turbo engines are fairly forgiving on cam selection compared to a NA engine. Curious what cam you had and what cam you installed?
 
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this one.
 
pulley 4 degrees advanced, 1 bar turbo pressure and this cam makes the X pretty jumpy.
 
Bjorn Nilson said:
Is this a X1/9 or an UT "race" cam? Would be interesting to know how the timings differ from my Strada/Regata cam with 9.5mm lift. I got tons of power and torque but completely dead above 7k. Is your engine more rev happy?
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Well. I hardly ever rev above 6k. So I wouldn’t know.
 
Bjorn Nilson said:
Is this a X1/9 or an UT "race" cam? Would be interesting to know how the timings differ from my Strada/Regata cam with 9.5mm lift. I got tons of power and torque but completely dead above 7k. Is your engine more rev happy?
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It was sold to me that way. But also that it was the max to fit with the standard UT. So I guess there are much more agressive cams, but I was not looking for them.
 
I think the added lift is what improved your performance. As noted earlier, with a turbo you do not want longer duration because that leads to overlap - which kills turbo boost. So lift is where you can make some gains.
 
I'm not clear about most of this. Which specific cams are you referring to - both the old one and the new one? Which engines are you referring to - the 1500 SOHC or UT? When you say without worries, do you mean non-interference or the cam will go into the engine?

To accurately compare two cams we will need to see all of the specs for both cams.
 
To clarify. I have two X1.9’s with 1300 UT identical engines. Both engines are fully standard UT engines with bosch ECU. The turbo pressure is about 1 bar. One engine is equipped with a higher than standard cam and an adjustable campulley. Both drive excellent. My holiday X has the standard cam. I am considering to switch the cams for a little bit more power on our travels. Besides that I bought a towhook for a trailertent. So a bit more power is welcome.
 
Mxgrds said:
Both engines are fully standard UT engines with bosch ECU. The turbo pressure is about 1 bar. One engine is equipped with a higher than standard cam and an adjustable campulley.
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The standard UT engine is an interference engine. If you want more power use a cam with more lift. However, changing the timing as you did with 4 deg advance seems risky as you increase the risk for interference even more. Modified pistons may be needed to prevent disaster if the cam lift is too high and/or timing not matched. Cams that are proven to add more power to the UT engine are the X1/9 1500 EU cam and the Strada/Regata cam, but I doubt the stock ECU can be mapped to handle them. Basically the adjustable cam pulley is for compensating for correct timing on a modified (shaved) head and maybe for increasing power if you know what you are doing.
For reliability AND more power (+140hp), upgrade the turbo and ECU. I assume you got 1bar boost just by disconnecting the pressure sensor wire as the Bosch ECU is not programmable.
 
Been lucky then. Nothing happened, gained quite some power, cars drives smoothly in low and high revs. Checked interference before starting the car by manual turning the engine. Considering to change to a programmable ecu.
 
Been lucky then. Nothing happened, gained quite some power, cars drives smoothly in low and high revs. Checked interference before starting the car by manual turning the engine. Considering to change to a programmable ecu
 
I agree with what Bjorn said.

I'm a little surprised the stock ECU will support 1 bar boost. Do you have a wide band O2 setup to see if it is running lean under boost? I think it would be a big improvement to switch to a aftermarket ECU with the increased boost and hotter cam. Maybe also a larger intercooler to keep internal temps from soaring.

Towing a trailer with a boosted engine is a risk. The combustion chamber temps are already high so detonation can become a huge problem, destroying your engine. Add to that the load of towing, especially with a tiny car not designed to tow loads, and you will likely burn pistons, valves, etc. I know I would not try it, sorry.
 
As said earlier, I hardly drive the car hard. Speed limits in the Netherlands are max 100km/h and 60 in rural area’s. Turbo pressure is only used when acceleration onto a highway and occasionally for fun. The engine gets only hot when standing in a traffic jam. Forgot to mention that the engine in my ‘holiday’ X has the 101 hp variant with the lambda. The Uno turbo is allowed to tow upto 1000kg (braked), the X upto 750kg. My tow is about 600kg and with a tow the max speed is 90km/h. We’ll see. It’s an experiment. I am more worried about the ground clearance.
 
Dr.Jeff said:
I agree with what Bjorn said.

I'm a little surprised the stock ECU will support 1 bar boost. Do you have a wide band O2 setup to see if it is running lean under boost? I think it would be a big improvement to switch to a aftermarket ECU with the increased boost and hotter cam. Maybe also a larger intercooler to keep internal temps from soaring.

Towing a trailer with a boosted engine is a risk. The combustion chamber temps are already high so detonation can become a huge problem, destroying your engine. Add to that the load of towing, especially with a tiny car not designed to tow loads, and you will likely burn pistons, valves, etc. I know I would not try it, sorry.
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Hi Jeff. My stock uno setup runs at 1 bar as well. No problems. Just an fyi.
 
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