Losh's VR Ute build thread

[Lex]

They give an improvement throughout the entire rev range, because cam duration hasn’t changed but lift is greater. You’ll probably notice it’ll sound a little tougher too.

Will it go through more fuel?

 

[losh1971]

They give an improvement throughout the entire rev range, because cam duration hasn’t changed but lift is greater. You’ll probably notice it’ll sound a little tougher too.

i was considering swapping the tailpipe with a straight through instead of resonator but am fearful it would drone.

 

[EYY]

Will it go through more fuel?

Only if you put your foot into it more but I would expect any difference to be marginal for normal driving conditions.

i was considering swapping the tailpipe with a straight through instead of resonator but am fearful it would drone.

I wouldn't - they lose the deep throaty note you get with a decent single 2.5" pipe with resi and they become obnoxious and raspy. I had a single 2.5" with 10"x4" mid muffler and a 5"x14" rear resi and it was nice - didn't drone and sounded good for a v6. What system do you have from extractors back again?

 

[losh1971]

Redback cat back, with fairly large rear resi.

 

[EYY]

Redback cat back, with fairly large rear resi.

Personally I'd leave it as is then - removing the rear resi will only have an impact on noise, not performance.

 

[losh1971]

Yeah i thought removing the rear resi would have mass drone. Before i replaced the old cat back it droned like a bastard on the highway. Could hear it in cab bad at 100kph. Sounds much better having a resi. If i want note I'd have to drop in a 304.

 

[VS_Pete]

I'm now looking forward to the rockers like you have Pete. Would you say they also improved down low torque?

What EYY said

 

[losh1971]

Will it go through more fuel?

it would appear so far that with the CAI alone fuel economy has improved. I'm only guessing but with a full tank the other day, i have now done probably 250km towing 700 - 800kg of additional weight and i am still on 2/3 of a tank. Previously i am pretty sure I'd be below half by now, hauling that much weight. I will do some better testing when I travel unloaded. But what i have found is that with the CAI i am using probably 20-25% less throttle and getting the same power. Now that's only towing figures as i have been working my other job most days this week and trailer is yet to be unhitched.

 

[losh1971]

Quick update, here is the latest diagnostic screen shot. MAT fluctuated a bit but rarely went as high as 40deg. Average was around 37-38deg, which is roughly a 5-6deg MAT drop compared to the standard air box.
I did a run without the trailer attached and it's better than with the stock air box. It seems to shift better but extra grunt wise it's not as noticeable unladend as it was with the trailer attached, and running stock box. It's still a noticeable improvement. My next two tests will be with light throttle and no load, where as just now it was WOT where I could. I will also wrap the intake tube with tape and retest.

 

[losh1971]

So quick update. I have wrapped the intake tube and the MAT was actually hotter today than yesterday. However I think my testing is flawed as I spent an extra 15mins with the engine idling, while I got the software to sinc with the PCM. I reckon as a result the manifold had some stored heat that maybe I did not have yesterday. I did feel the intake tube and it was barely warm, so I would say the wrap is having some affect on lowering the temp inside the tube. Now whether it is enough to make a difference in the MAT over running the CAI alone is hard to say. Ideally I would go to the wreckers and grab another intake tube and doing the testing within a few mins of each other. I have raised the bonnet and am hoping to get the MAT temp down before I go for my next run in 10 more mins time. Ideally I think to carry out accurate tests I need to have the sensor located in the second elbow on the intake tube, but that is a bit tricky at this stage.