60V6 Major Horsepower Bottleneck(s)?

[ItsVince725]

The stock 60V6s are all rated at rather low horsepower numbers. Given that the engine has a lot of potential, what exactly causes such low stock HP numbers?

[robertisaar]

shitty exhaust manifolds/downpipe would be my #1 offender.

[ItsVince725]

shitty exhaust manifolds/downpipe would be my #1 offender.

I had a feeling that was one of the causes.

Are there 3100/3400 headers out there? Because if I can pick up an easy 30/40 horsepower by changing the headers and downpipe, I will.

[robertisaar]

WOT-Tech were making them for a while..... might be still.

but a word of advice is that pacesetter headers = BAD. horrible fitment issues along with a bad design.

30-40 from headers alone might be a stretch, but with some intake improvements(notably the large port UIM/LIM and larger throttle body), probably could see that, depending on what you start with.

[ItsVince725]

WOT-Tech were making them for a while..... might be still.

but a word of advice is that pacesetter headers = BAD. horrible fitment issues along with a bad design.

30-40 from headers alone might be a stretch, but with some intake improvements(notably the large port UIM/LIM and larger throttle body), probably could see that, depending on what you start with.

I was already planning on grabbing a 3400 throttle body for my 3100 off WOT-Tech, because that's a couple minutes of work for a couple more horsepower. Can't go wrong.

[Mars]

There is alot left on the table in the camshaft as well.

A cam only otherwise stock 3400 can likely pickup 40HP +

[ItsVince725]

It's good to know that there's a good amount of power that can be pulled from a 3100/3400 without going straight to forced induction.

[Superdave]

There is alot left on the table in the camshaft as well.

A cam only otherwise stock 3400 can likely pickup 40HP +

Agreed, the stock cam sucks.


It also depends on what 60v6 you're talking about though, gen1's have junk heads, gen 2's have junk heads stock but they can be ported to flow decently, but their LIM/UIM combo kills most porting gains. Gen 3's flow good stock but can really flow with good porting.

[ItsVince725]

Agreed, the stock cam sucks.


It also depends on what 60v6 you're talking about though, gen1's have junk heads, gen 2's have junk heads stock but they can be ported to flow decently, but their LIM/UIM combo kills most porting gains. Gen 3's flow good stock but can really flow with good porting.

A 1995 3100 SFI is Gen 2 or 3, right?

[Superdave]

early "Small port" gen 3. 94-99 3100's have smaller runners as you can see in this picture: (hopefully it shows up)





Those 3100's can gain some noticeable power by swapping to a large port lower and upper intake from any year 3400 or a 2000+ 3100.

[ForcedFirebird]

WOT-Tech were making them for a while..... might be still.

but a word of advice is that pacesetter headers = BAD. horrible fitment issues along with a bad design.

30-40 from headers alone might be a stretch, but with some intake improvements(notably the large port UIM/LIM and larger throttle body), probably could see that, depending on what you start with.

Making a set of headers right now

[ItsVince725]

Is an intake swap a simple case of getting a new intake and gasket set? I'm not sure if the LIM bolt locations are the same when comparing a 3400 large port intake to a 3100 intake. If not, I would have to drill and tap all new bolt holes...

[robertisaar]

Making a set of headers right now

always good news.

Is an intake swap a simple case of getting a new intake and gasket set? I'm not sure if the LIM bolt locations are the same when comparing a 3400 large port intake to a 3100 intake. If not, I would have to drill and tap all new bolt holes...

where the LIM bolts to the heads is identical, the large port intakes have a different UIM to LIM bolt pattern, which is what you're seeing in that pic. so long as you use a larger port UIM with a larger port LIM, you'll be fine.

you'll also have a few smaller issues to deal with due to being a 95, but they really aren't that significant.

[ItsVince725]

That's what I wanted to know, I plan on using both a large port UIM and LIM but wanted to make sure the large port LIM would bolt to the existing head bolt locations.

[Purple pit]

Just do what I didn't. Spend the money on ported 3400 intakes and have the hole for the coolant by-pass tube tapped to work with your stock tube.
I'm not sure what "level" of porting is ok with OBD1.5. That is if you want to avoid tuning.