VW Vortex - Volkswagen Forum banner
Cancel

turbo questions?

1084 Views 12 Replies 6 Participants Last post by  A2 VW, 
R
lookin to set up turbo.....about 5 pounds.....how do I adjust fuel on cis. and do I have to lower the compression....thank you
Reply
Save
Like
1 - 13 of 13 Posts
F
Re: turbo questions? (reillymk2)

Junk the CIS, get the G60 Digifant... it was designed for boost. up to 14.7 lbs. on stock computer. With a chip you should be allset to run 5 lbs
To run 5 lbs you don't really have to lower the compression, if you want to run upwards of 9 or 12 you might want to get some JE forged pistons with a 9:5.1 ratio, or double up on head gaskets.
Reply
Save
Like
R
Re: turbo questions? (FragileGTI)

The car will not run at full potential if you were to boost 14.7psi without modifying the timing curves.(chip) That 14.7psi number that youve got has to do with the max psi that the MAP sensor can read with no modification.
As for junking the CIS, why would you say that? Considering he is only planning on running 5psi there is no need to change injection systems. Through the use of an Audi 5000 turbo warmup regulator, a presure activated switch that is run inline with yer full throttle switch and a boost retard diaphram on yer distributor you can run upto 10psi with relative ease.(intercooled of course)
Lowering compression depends on which engine you have.
Reply
Save
Like
2
Re: turbo questions? (Rabbid Rabbit)

you should also use a saab 900 fuel distributor
Reply
Save
Like
E
Re: turbo questions? (2nutz)

Here is what I am doing 2.0L 10.5:1 (no it will not blow up) , Euro Infection, CAM2 (118oct) intercooled pushing 7lbs on teh street and hopefully 1 bar at the track.
See less See more
Reply
Save
Like
R
Re: turbo questions? (eurotrashrabbit)

1 bar on 10.5:1 compression?(thats 14.7psi) Youll probably need water injection as well. http://www.aquamist.co.uk Euro injection wont really do anything for you. To be honest, Im not too sure that CIS will be up the task of fueling such a high compression/boost motor without the aid of some kind of extra injectors. Personally, I wouldn't attempt this on motor that has not been rebuilt with heavy-duty internals, however that would be one sick a$$ car!
Reply
Save
Like
E
Re: turbo questions? (Rabbid Rabbit)

Well I know guys doing the same thing on 7-8 lbs of boost , with CIS, no blown up motors yet. I was thinking about running the SDS add on injector kit. It is very inexpensive only about $200 for 2 more injectors.
See less See more
Reply
Save
Like
R
Re: turbo questions? (eurotrashrabbit)

7-8 psi is doable with no extra injectors, however the theres a BIG difference between 7 psi and 15psi! Just make sure youve got the appropriate fueling and youll be fine.
Reply
Save
Like
E
Re: turbo questions? (Rabbid Rabbit)

I agree I would only use 1 bar at the track on a pass. This thing will rip. Well I have decided to run lower comp 9:1 so I will not blow up any motors. I am getting 2 more Audi 80 motors. So I am going to have a turbo motor , high comp motor 12.5:1, and a built track motor 11:1 comp high rev motor.
See less See more
Reply
Save
Like
R
Re: turbo questions? (eurotrashrabbit)

thanks guys ...much appreciated
See less See more
Reply
Save
Like
A
Re: turbo questions? (reillymk2)

Isn't lowered compression (8.5:1 or 8.7:1) better for turbo applications? On top of that isn't higher octane race fuel also better on lowered compression?
Reply
Save
Like
R
Re: turbo questions? (A2 VW)

Compression depends on the amount of boost youre running. High compression+high boost=kaboom(without the proper precautions) In general it is preffered to have relatively low compression when dealing with F/I(8-9:1)
High octane fuel is only needed when you either run high boost or high compression, or both.
Its not a very good explanation, but basically the higher the octane the higher the flashover point. This means that 110 octane fuel takes more heat to burn then lets say 87 octane. This is needed because high boost/compression engines tend to ignite lower octane fuels before they should.(knock)
See less See more
Reply
Save
Like
A
Re: turbo questions? (Rabbid Rabbit)

Oh yah I heard about the knocking of low octane fuel if under FI, thanks! Learn something new everyday on Vortex!
Reply
Save
Like
1 - 13 of 13 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
VW Vortex - Volkswagen Forum
A forum community dedicated to all Volkswagen owners and enthusiasts. Come join the discussion about performance, builds, modifications, classifieds, troubleshooting, maintenance, new releases, and more!
Full Forum Listing
Explore Our Forums
The Car Lounge Golf IV & Jetta IV Golf III & Jetta III Golf II & Jetta II Golf IV/Jetta IV Parts
Top