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Sandeep October 19th 2003 14:02

Turbo placement for Type 4 engine converted bug
I'm leaning more towards a small (1971cc) T4 turbo'd engine (9-10 psi max boost) now than a 2.5L NA motor. I've got the book 'Turbomania' from CB performance and I know its a little outdated but there is some great information in there.

I've found out that you can get turbo-prepped Weber IDF's (Blow-through) now aswell so perhaps I can swap my webers for the turbo-prepped ones.

I'm just doing the research on a turbo system now.

I have 2 questions :

1. Can I use my BAS header and bolt an extension to it to place the turbo (undecided size yet) near the transaxle, but higher than the engine sump ? Or do I need a specific turbo header ? I was hoping to be able to use the BAS but not modify it at all.

2. Does the turbo header have to be a really short combination or can it be longer ? It seems like the headers I have seen tend to be built with turbo placement as the governing factor instead of correct header length ?

I'm really excited about this possibility also because there seems alot more people who are trying this. EBay has some good turbo deals ($ 250 USD for a rebuilt T03) right now.

Thanks for any input.


kdanie October 20th 2003 00:08

I think you could use your BAS header. You may experience a little turbo lag because of the distance the gases must travel but if you ceramcic coat it inside and out, that will help some. The key is keeping the heat in the exhaust gases.


Turbonutta October 20th 2003 07:37

sandeep i just wrote u a reply and i pressed the wrong button and i lost it .......
its all trial and error
i havnt even run my set up yet....
but my turbo is a long way from the cylinder i possibly may have a bit of lag..but you can get round this with a correctly sized turbo and correct diameter tubing..
if you look in the cb perfomance book at the turbo 914 the pipe lenghts are massive but the caption tells of how great the performance is....Dont listen to every one try what you think will work then if it doesnt try again
this hobby is all about given it a go......

Sandeep October 20th 2003 08:56

Thats why I installed the FAT 911 setup. I kept reading that it would not fit a beetle with a decklid .. even the folks at FAT told me it would not fit. Guess what ? With a LITTLE modification, it does fit !

I saw the 914 pic in the Turbomania book and that is what prompted the question. Thanks for the responses !

I will get the header ceramic coated, and the dia of tubing after the collecter on the header is 2" OD. so I guess it will be 2" up to the turbo flange.

I am not looking for crazy HP .. looking for about 150hp to start with on a stock 914 2.0

I'm working through understanding the A/R ratio and how to determine what turbo to choose. I'm sure I will have more questions !

Sandeep :D

Sandeep October 20th 2003 11:04

1 Attachment(s)
Here's what I mean by keeping my BAS header. The idea in the pic is the same but the location of the turbo will change ! See how the header is stock but a pipe is made up to mate the header with the turbo.


Turbonutta October 20th 2003 11:53

hhm i reckon thatll definately do the yours going to be a draw through or blow thru..??

Sandeep October 20th 2003 13:07

I'm planning blow-through but that could change as I do more research. :eek:


Massive Type IV October 20th 2003 15:19

I will be introdcing the "2058 T" engine very soon.....This is a Turbo, long stroke, long rodded engine that does not require Nickies to keep the heads sealed running boost.....225 BHP is the proposed power, we'll see when we get it on the dyno.

NOTE: These engines will not be sold complete, they will be sold with cooling system and tested with carbs. Customer will be responsible for Turbo, and exhaust/induction systems and their configuration(I will aid when needed)

blue4400 October 21st 2003 10:04


Originally posted by Sandeep
I'm planning blow-through but that could change as I do more research. :eek:


*Blow-through will make more power than a draw-through set-up.
*Intercooling will also help your hp numbers. I'm tring to figure out a way to run a intercooler. I was on friends computer doing a couple of different projections, just by adding an intercooler I can make an extra 40 - 60 horses. I know a lot of VW don't use them but it's worth it.

I'm currently building a turbo motor. Like you I'm also doing the research, but as I go.
2110 - 82mm crank, 90.5pistons, with 5.6 rods.
I purchased the CB hideaway turbo header and fuel injected throttle bodies, Electromotive Tec2 computer, CB street eliminator heads ported, polished, and redesigned the dome a little to reduce hot spots and increase air flow. Because of the header I can't use a t-4 exhaust housing but I wanted to. Turbo setup consist of a lot of trial and error. I'm starting with a t3/t4b with a .63 exhaust side. I really want to come close to or break the 300hp mark using a T1 case.

Sandeep October 21st 2003 10:59


That's great. Let me know how the Tec2 works for you because I want to go FI in the future after I get this engine set up.

My car is going to be off the road in a couple of weeks (stored for winter) so thats when the R&D will start.

Where would you place the intercooler ? What boost range do you start needing an intercooler ? I want to keep the car looking stock (keep decklid on) so I think alot of the system will have to be under the car, in the transaxle area.

Possibly ducting cool air to the intercooler in an option ?


blue4400 October 21st 2003 11:50

I'm not sure yet, the only place I can think about is behide the rear seat. I want to kept the lid on (sleeper).

You really don't need an intercooler at all, but it only helps. Remeber the cooler you kept the air the more power you will produce. When you crank up the boost, compressing the air into the motor it will result in more power. At the same time you will be losing the potentional of a lot more power because the more you compress the air the hotter it gets. Water injection is a good thing too, if you don't want to run an intercooler. I hope that is of some help. It all depends how much power you want to make.

Turbonutta October 21st 2003 12:01

if you want serious power you need a cooler,i have gone for a charge cooler as there isnt much room for an air to air cooler or intercooler. engines like nice cool dense air so cooling the air with a cooler is the way to do air leads to pr-ignition etc you can spray water into the engine to help cool but its not really an cant depend on a tub of water to look after your engine.
if you look at my pictures on the 2.1chargecooler post you will see the location of my cooler,and the radiator in the front wheel well.i have lost all the space behind the rear seat but id rather have a turbo than a bass box sat there....?Turbo mania isnt out dated its a great book for learning what every thing is the book im reading is MAXIMUM BOOST BY CORKY BELL>> its great a stepping stone from turbomania

Sandeep October 21st 2003 12:32

Great information guys !

I have just completed a spreadsheet to determine what type of turbo I should be looking for.

It has the following variables:

1. Engine displacement in cc's (1971)
2. Engine's volumetric efficency (85%)
3. Desired boost pressure (10 psi)
4. Engine rpm range (2000,3000,4000,5000,6000)

It calculates the pressure ratio using atmospheric pressure for all RPM's and gives me a boosted lbs/min of airflow.

I now have to plot the values on some turbo compressor maps to find the right turbo.

By playing with the values, I found out a 1971cc @ 14 lbs boost (6000 rpm) will flow as much lbs/min of air as a 2270cc @ 10 lbs of boost (6000 rpm). (23.91 vs 23.70)

Not sure how accurate this is in the real world but it seems like boost is the 'great equalizer' :D


samcat October 21st 2003 12:35

You dont need to lose the option of having a sub box either.... Even if your behind rear seat area is full.....

Basically you can build a fibreglass box on one side under your rear seat (where the battery goes on one side). So long as you get a sub designed for a small box (0.6 - 0.8 cuFt) then you can build a subbox in down there...
I am moving my battery to the front of my car sometime soon, and will be putting a sub down there on each side. :)

Sam C

Sandeep October 22nd 2003 09:03

I have plotted my data points on different compressor maps (2000, 3000,4000, 5000 and 6000 rpm) and I have a question.

How do you know when the turbo is starting to boost ? Some points result in a compressor speed of about 70K rpm and some result in over 110K rpm.

Do you want the plotted line to end up in the 'island' mostly, meaning the 6000 rpm data point, or is it ok to have the 6000 rpm data point be off the island ?

I haven't found a site on the web yet that can explain it, and am not confident enough to call a turbo shop and talk 'Turbo' with them :D



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