Rear mounted turbos

**Oneofthegreats** · 04-11-2006, 07:25 PM

IMO I wouldn't bother. There's enough room in any golf engine bay to fit a turbo in.

Depending on what type of turbo you run, you'd also need a very long coolant lines too which are exposed to a very abusive environment. You'd also need a pump of some sort(Holley Blue) to scavage the oil from the turbo & pump it back to the engine which will also be exposed.

I've seen this setup on some car's & I won't deny it doesn't work, it would fine, but I would question the overall efficency of the setup.

Any engine can be turbo charged regardless. Depending on how much flow, boost & especially cyl. pressure's(that's the important one) you require depends on how you must build the engine within reason as some of today's engines don't need any modification's at all.

For eg. the current gen4 LS4 has a static CR of approx 10+:1 & you can fit GT42R to them on pump fuel & with the right setup & tuning can easily make 400+RWKW!

Stock standard 20VT's with a CR of 9.5:1 can make 500+hp with the right setup.

10 year's ago it was unheard of that any turbo'd engine had anymore than 8.5:1 CR(except for diesel's

), but with ever increasing engine component quality, turbo's & engine management technology this has changed the way people think about forced induction of any kind.

**Bug_racer** · 04-11-2006, 09:03 PM

Originally Posted by golfworx

Stock standard 20VT's with a CR of 9.5:1 can make 500+hp with the right setup.

I have to disagree here , 400hp is the most you can get out of the 1.8t before you should be upgrading the rod bolts . You probably could get 500hp but not reliably . After 450 hp though you'll need to run a gt30 and you'll have to lower compression ratio due to static compression being too high for the turbo size . You will also have a problem with the piston rings and gt-30's .

Apart from that everything else is correct , its a waste of time .

**Oneofthegreats** · 04-11-2006, 09:14 PM

Originally Posted by Bug_racer

I have to disagree here , 400hp is the most you can get out of the 1.8t before you should be upgrading the rod bolts . You probably could get 500hp but not reliably . After 450 hp though you'll need to run a gt30 and you'll have to lower compression ratio due to static compression being too high for the turbo size . You will also have a problem with the piston rings and gt-30's .

Apart from that everything else is correct , its a waste of time .

Yeh I just realised. I should have said the BAM/TT225 engine's CR 9:1. They can & have done 500+ even with the AEB's & AGU's but your right, after 400 with a larger frame turbo's the rod's can't really withstand the cyl. pressure's & start to bend. I've never heard of any problem's with the BAM piston's nor anything about the standard ring's.
I've seen them modify(open up) the top & second ring gap's but only if there running after market piston's eg. JE, wiseco etc.

**Bug_racer** · 04-11-2006, 09:23 PM

They are using thin rings on BAM pistons which over time start leaking . I have seen some actually crack and snap . Definately need thicker rings for more boost .