Big 16g on 14b hotside

[Sparknutz]

I have a big 16g compressor and chra and a complete 14b off a 91 tsi. I was wondering how well the 16g compressor would work with the 6cm^2 housing, and how much that would affect spoolup/airflow/effeciency of the big 16g vs the intended 7cm^2 housing, and if I have to have my turbo rebalanced after mating the two? I intend on running hillclimbs with the car so midrange power definitely comes into heavy consideration.

I'm mainly concerned with how much boost should I plan on running safely with that combination? I haven't decided what type of fuel control I am going to be running as of yet, I currently have a walbro 255, no afpr yet, 3" exhaust w/ ported evo 3 o2 housing, ported 2g manifold and hallman mbc.

A FMIC with hard piping is on my short list of parts to buy at this point, but I've been working on an auto/manual conversion at the moment so I haven't wanted to get into fabbing up any IC pipes as of yet until I get my car at least running again.

My main reason for even getting the 16g at this point was price at the time, and my 14b had 155k on it.

Thanks in advance.

 

[92_talonGsXt]

Using the 6cm housing on your 16g will gain you quicker spool but will choke topend,you don't have to rebalance your turbo if you swap hotsides,it's a bolt-on.As for running safely on a basically stock set-up, 14 psi is what I recommend

 

[fwdmaster]

+1 couldn't say it better myself

 

[Sparknutz]

When you guys say "choke" topend how much are we talking here? Would it be better to hunt down a 7cm^2 housing? I would assume hillclimbs would want similar setups as autoX and road racers. In my division, switching within the models is free, so I was going to get some evo 8/9 560cc injectors and probably dsmlink in the very near future. I'm curious as to what my ceiling will be with this setup, and if it'll help or harm me in the long run for my intended purpose.

Thanks for the input thus far

 

[jdunbar10]

its not going to affect it to the point where you will really notice it but in the end you kinda have to decide you want more torque or top end

its not a real big difference but still something

 

[toofast82]

It really depends on how much boost you are running. At some point the housing will not be able to flow enough to match the turbine flow.
At 10-15psi, the 6cm should flow plenty. Some point after that it will begin to hinder topend flow.
Keep in mind a 6cm is about .42-43a/r while 7cm is ~.48a/r, so it's not a huge difference either way.
Some time back I switched my 14b's 6cm to a 7cm and there were nice topend gains, while the extra spool was hardly noticable. I was running 20psi though.

 

[Sparknutz]

Thanks a lot for the input guys. I just wanted to make sure I wasn't going to be screwing myself too bad. I'd like to get it somewhere up around 20psi, but I know I need injectors, fuel control, and probably a set of ARP head studs so I don't tear it apart. Midrange power and torque are what I'm really going for, but reliability is also quite important. The mountains are usually between 2-4 minute tracks, with pretty steep inclines and several turns. I don't want to a point where I just heat soak it after a few runs, depending on the track there are usually 3-8 runs in a day. I'll never have a chance to be at full boost for extended periods of time, but I'd like a smooth enough power band that I don't have to worry about snapping drivetrain hitting it out of a turn.

I've been hitting up the classifieds, and the trader pretty hard trying to get some parts. If anyone knows of something specific that I should put on my shortlist of mods for my goals, the info would be appreciated. I'm not chasing a specific drag or hp goal, but I think I'd like to be able to pull off a 12 in the 1/4 should I ever decide to go. I'm going to update my profile to reflect my recent purchases as well.