Hi all!
I have finally got round to getting the polo sorted again, thought I would make a new thread so all comments and opinions welcome
After making 400hp @ 1.7bar (gt3071r 0.62 a/r) and losing soo much oil I decided it was time to open the engine and see whats whats.
I checked compression and on cyl 3 and 4 they were very low.
My old engine which I purchased re-built allready had alot of problems which i didnt know about, I was using approx 1 ltr of 15w50 oil every 200 miles!
After opening the engine we found the rings never bedded in properly!
The guy who overbored it didnt hone it enough as they bored more than they should have!
Also one of the lifters failed
And the little end bearings were worn so the pistons were scoring the bores...
So considering how bad my engine was running now I am very pleased with making 400hp on that engine.. the map from JBS was spot on!
Well since then I have had the engine re-built professionally by JNL Racing and I have also got myself a race-spec large port head, Cams, and a new turbo!
I was getting my head ported and polished but due to the ceramic from the spark plug wedging into the head cyl 3 needed loads of porting which inturn had to be matched on the other cylinders so the head was ported and polished substantially.
The Intake tract flows physically 22% more across the entire cam lift range compared to that of a standard large port head, The Exhaust tract has been designed to aid spool up and is very susceptible to creating a boost spike in a space less than 300rpm from when it starts to come on boost.
I also changed the intake cam which should give better top end.
And I went for the owens gt3076r 0.82 a/r...
I have had everything back in and run-in, just waiting for a bit of Custom Code tuning by JBS now!
I have been running off the old map and running with the wastegate spring only and going upto 1bar, but it feels very strong.
I have seen 1bar @4k in 4th gear but running rich so hopefully that will go down!
I also have the N2MB WOT box which JBS will be setting up for me and the sigma short shifter which has transformed the feel..
Here are a few pics..
Owens GT3076R with 0.82 backhousing.
Stripped alot of unused wiring!
Engine back from JNL Racing
So far the car feels like it drives better off boost from the previous setup, the turbo is defo laggier but it still feels really strong if you ignore the boost gauge and forget there is turbo for a second!
With the 3071r it would still build a bit of boost, with this one its like everything at once but I love it!
I haven't done any logs yet, is there any I could do to give a comparison? E.G MAF logs at 1bar boost?
I know I can easily get 500 hp with my setup possibly more but I have told JBS to set it with a broad power band and make it as driveable as poss rather than just high numbers.
Thanks for reading, I will update as things progress..
Thanks for looking...
I have finally got round to getting the polo sorted again, thought I would make a new thread so all comments and opinions welcome
After making 400hp @ 1.7bar (gt3071r 0.62 a/r) and losing soo much oil I decided it was time to open the engine and see whats whats.
I checked compression and on cyl 3 and 4 they were very low.
My old engine which I purchased re-built allready had alot of problems which i didnt know about, I was using approx 1 ltr of 15w50 oil every 200 miles!
After opening the engine we found the rings never bedded in properly!
The guy who overbored it didnt hone it enough as they bored more than they should have!
Also one of the lifters failed
And the little end bearings were worn so the pistons were scoring the bores...
So considering how bad my engine was running now I am very pleased with making 400hp on that engine.. the map from JBS was spot on!
Well since then I have had the engine re-built professionally by JNL Racing and I have also got myself a race-spec large port head, Cams, and a new turbo!
I was getting my head ported and polished but due to the ceramic from the spark plug wedging into the head cyl 3 needed loads of porting which inturn had to be matched on the other cylinders so the head was ported and polished substantially.
The Intake tract flows physically 22% more across the entire cam lift range compared to that of a standard large port head, The Exhaust tract has been designed to aid spool up and is very susceptible to creating a boost spike in a space less than 300rpm from when it starts to come on boost.
I also changed the intake cam which should give better top end.
And I went for the owens gt3076r 0.82 a/r...
I have had everything back in and run-in, just waiting for a bit of Custom Code tuning by JBS now!
I have been running off the old map and running with the wastegate spring only and going upto 1bar, but it feels very strong.
I have seen 1bar @4k in 4th gear but running rich so hopefully that will go down!
I also have the N2MB WOT box which JBS will be setting up for me and the sigma short shifter which has transformed the feel..
Here are a few pics..
Owens GT3076R with 0.82 backhousing.
Stripped alot of unused wiring!
Engine back from JNL Racing
So far the car feels like it drives better off boost from the previous setup, the turbo is defo laggier but it still feels really strong if you ignore the boost gauge and forget there is turbo for a second!
With the 3071r it would still build a bit of boost, with this one its like everything at once but I love it!
I haven't done any logs yet, is there any I could do to give a comparison? E.G MAF logs at 1bar boost?
I know I can easily get 500 hp with my setup possibly more but I have told JBS to set it with a broad power band and make it as driveable as poss rather than just high numbers.
Thanks for reading, I will update as things progress..
Thanks for looking...
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