7cm housing lag?

[PLYMOUTH TURBO]

I'm replacing my stock 1g manifold to a Fp race manifold and wanted get a evo 3 7cm hotside to match up with the manifold, will my 14b lag with the 7cm housing?

 

[cruisintalonawd]

No your just getting better air flow

 

[Dsmj89]

As crusin said it will be much better. It's a bigger outlet from the exhaust mani pushing much more flow so i wouldn't see why there would be a problem.
If the mani outlet were smaller then yes it will cause an obstruction.

 

[Demon33]

I'm replacing my stock 1g manifold to a Fp race manifold and wanted get a evo 3 7cm hotside to match up with the manifold, will my 14b lag with the 7cm housing?

When I still had my 14b I ran it with a 7cm turbine housing from a 16g and I never noticed any increase in the lag. I fact, there was a nice gain up top and I felt my useable RPM range was increased a little, as the bigger turbing housing choked the exhaust less. It's much like clipping the exhaust wheel- it'll reduce back pressure and increase your top end a little without dramtically sacrificing spool. I was very happy with my setup and I think you will be too, especially with the FP manifold added to the mix.

 

[JayRolla]

Usually larger housings will slow down spool a little. Its just how it works. On that fast spooling turbo you wont notice a difference except more airflow at the same boost levels which is always good.

 

[the_mork]

Repeatedly those who have switched to a 7cm housing have had nothing but good things to say about this swap. I have never heard someone say that they were unhappy with their swap.

 

[habitatguy187]

Done it, full boost (20psi) is about 300rpms later.

 

[DSMunknown]

I highly recommend it to get the most out of the 14B.

 

[dsm-onster]

Done it too. Full spool was about 400rpms later. Clipping noticably slows spool speed and so does a larger critical area (turbine housing upgrade). Well worth it, however. Be prepared for a totally different feel at 20psi!

[looked at your profile] And unless you have an injector upgrade be prepared for teeth-in-stearing-wheel fuel cut. As well, unless you have a maf upgrade, you'll blow your headgasket or motor anyway with the added flow at higher boost and a meter that cant read that high.

If you plan on keeping things below a boost that through logging you can determine will keep you under the metering limits of the 1g maf and keep you under fuel cut with stock injectors (sub-16psi with stock long block for most), then upgrading isn't really worth it.

Be prepared, there's more than 2 who've said their swap to the FP race manifold slowed their spool. But that is probably a good thing, as that means the motor flows better and it taeks more compressor rpm to see a certain boost threshold. A larger turbine housing AND an fp race manifold may give you a healthy amount of lag, but nothing that won't be meritted for the topend pull at moderate boost levels (18-20psi).

As crusin said it will be much better. It's a bigger outlet from the exhaust mani pushing much more flow so i wouldn't see why there would be a problem.
If the mani outlet were smaller then yes it will cause an obstruction.

What are you saying? It's not about the outlet diameter of the exhaust manifold. Critical area is NOT at the inlet. You can't just port the stock 6cm^2 turbine housing at the inlet an make it work anywhere near where the 7cm^2 works. The topend is MUCH better with a real turbine housing upgrade.

 

[skatershawn]

so replacing the hotside on a 14b is A OK?? but replacing the compression housing on the 14b to a a 16 isn't??

i wanted to make a hybrid but was talk out of it because i was told it wasn't worth it and it would cost more to do, that i should just buy the evo 16g new!!

 

[skatershawn]

but if changing the hotside is that easy and get a gain off of it... ill just do that!
can we break this down for me??
thanks

 

[pboglio]

Done it too. About a 400 rpm loss, I.e. 2800 rpms vs. 3200 rpms. On my car, no, it wasn't worth it. Jumping straight to the 16g was worth the extra lag for me. The 7cm housing on a 14b
just made the bottom end soggy with no noticeable increase in topend up to 21 psi that I could detect.

Not sure I agree with the FP manifold hurting spool per say. It just doesn't make as much torque down really low, say below 3000 rpms. If you aren't running a heatshield on an FP manifold or the garbage ceramic coating they came with, then the extra heat coming off of it will make the turbo spool slower.

 

[jrohner]

My E3 16G hits 25psi by 2800 RPMs in 5th (and that's after the FMIC hurt it 300 RPMs), so I can't really imagine a much quicker spoolup than that. Go for it!

 

[dsm-onster]

We don't play with out cars in 5th. And no one even really runs in 5th at the autox or even gets to 5th at the drag strip. The true test of spool speed is in 3rd. That 2800rpm spool speed for your 16g at 60mph is from the drivetrain putting alot more load on the motor and feeds the turbo alot more massflow to work with. My 60-1 would spool to full song (30psi) by 3300rpms in 5th

Done it too. About a 400 rpm loss, I.e. 2800 rpms vs. 3200 rpms. On my car, no, it wasn't worth it. Jumping straight to the 16g was worth the extra lag for me. The 7cm housing on a 14b
just made the bottom end soggy with no noticeable increase in topend up to 21 psi that I could detect.

Not sure I agree with the FP manifold hurting spool per say. It just doesn't make as much torque down really low, say below 3000 rpms. If you aren't running a heatshield on an FP manifold or the garbage ceramic coating they came with, then the extra heat coming off of it will make the turbo spool slower.

Many have said that the fp hurst spool a little. But that's not to say that the manifold isn't flow a lot of air in the midrange and thus it takes more for the turbo to see a certain boost threshold.

I saw a difference once I started pushing the 14b past 20psi. The turbo acted like a 16g, seeing big gains going up one psi a time from 20psi to 25psi. . . This was on stock cams.

 

[skatershawn]

ok so im a bit confused... no to swaping the 14b hotside to 16g?
and Yes to getting a FP mani cause i was actually readying to get one aswell!

 

[dsm-onster]

You can run the 7cm^2 turbine housing on a 14b. Teh 14b has the same turbine wheel as all the 16gs. The housing will bolt right up. There will be gains up top. Too many note that. The hotside now flows like and IS a 16g hotside. You can get the same horsepower per psi as a 16g in the 20+ psi range up to the choke of the 14b compressor which is around 34lb/min. That's good for a bit over 300whp on pumpgas.

The compressor housings have identical geometries. There's no reason to swap it. Nor can you swap a 16g housing onto a 14b because the 16g compressor wheel is larger than a 14b compressor wheel. The 14b compressor housing can be swapped onto a 16g compressor wheel but the housign has to be machined for the larger inducer and exducer diameters of the 16g.

 

[skatershawn]

ok.... haha sorry i can be slow sometimes!!
well i was going to get the 16g compressor wheel and housing and put it on the 14b getting it balanced and everything cause i read it will bolt right to the 14b!
but swaping the hotside seems easier and cheaper due to the fact i don't have to balance it!!

thanks again!!

 

[toofast82]

I used to run a 14b/7cm. Hardly noticable lag and better flow per psi with the bigger turbine housing

 

[habitatguy187]

DSM-onster - You ran your 14b to 25psi? One of the guys (phil beers I think?) maxing out the 14b in the 1/4 said that the dyno on 21psi was 4hp higher than the dyno on 20psi. He is also using the 7cm housing I believe. Could you tell a difference?

 

[dsm-onster]

I'm sure he has cams and other flow upgrades. I did this with stock cams stock manifolds and 2.5" exhaust. Which many people run with a 16g to get 300+ whp. . .

 

[pboglio]

Here's an idea, try it out and see. I swapped turbine housings back and forth 4-5 times. FP manifold is gold IF your setup for it. Heatshielding it is critical, otherwise your going to lose whatever horsepower the improved manifold design generates. I just wire tie my old heatshield over it and its good enough for datalog testing until a real ceramic coating goes on.