Realistic gains to expect from an intake?

**04lss** · 09-26-2014

So ive been looking at intakes, and i saw on 3800 performance.com the claim that the motorsports performance CAI will add 18whp and 24 ft-lbs torque. This seems inflated to me, they have a dyno sheet but you can always fudge numbers.
their dyno sheet shows 223 whp and 300 wtq, with just the intake and a downpipe. this doesnt seem realistic, but i dont know.... id love to hear some thoughts on this. if it really does work, the whp is definitely worth the cost.

**Scottydoggs** · 09-26-2014

those are stock dyno #. there is zero gains form a intake. snake oil..........

**REDCRAPGP** · 09-26-2014

Bull****.. A intake alone will probably barely gain anything to you'll ever notice. A downpipe or headers on the other hand will give you gains but don't expect much.

Save your damn money and make your intake and have similar gains as those expensive intakes the vendors like to advertise and spend the difference on other mods or maintenance.

**Scottydoggs** · 09-26-2014

headers take power away unless you pulley down. i went from 7 psi stock, to headers and 5.3 psi of boost.

car felt better off the line. but thats it with headers.

**04lss** · 09-26-2014

Originally Posted by Scottydoggs

headers take power away unless you pulley down. i went from 7 psi stock, to headers and 5.3 psi of boost.

car felt better off the line. but thats it with headers.

so headers custom/purchased intake, and a 3.4/5 pulley for more hp?
im going to go e85 eventually but i want to drive the car for a while on pump while i get everything straight on it.

**REDCRAPGP** · 09-26-2014

Originally Posted by Scottydoggs

headers take power away unless you pulley down. i went from 7 psi stock, to headers and 5.3 psi of boost.

car felt better off the line. but thats it with headers.

That's why you pulley down Sally

And helps kills KR which in return makes everyone happy

**Scottydoggs** · 09-26-2014

Originally Posted by REDCOMPG

That's why you pulley down Sally

And helps kills KR which in return makes everyone happy

dont you sally me red lol my 3.4 pulley went on the next day after the header install.

**04lss** · 09-26-2014

I thought stock whp on the GTP was around 190 200,
I know on the monte carlos and the newer w-bodies you can gut the factory box and stick a cone in it. I heard that this does not work on the 97 gtp any suggestions on the best way to build one?

**04lss** · 09-26-2014

Im looking for about 30-40whp until i go corn, i was thinking the 3.4 and headers might come close to that, if not what else would i need to add? rockers maybe?

**Scottydoggs** · 09-26-2014

still no gains. its all bull sh it. you will hear the whine, thats it. chances are you'll get worse mpg cause your nailing the gas all the time to hear the blower whine.

i made a diy intake for 35 bucks. it noes nothing just like the 100 dollar intakes. dont believe the BS.

**Scottydoggs** · 09-26-2014

headers and a 3.4 pulley will add a fair amount of power. then the E85 will add more power, cause you can run a smaller pulley on corn.

but if you go smaller pulley for corn you'll need larger injectors, better fuel pump up grade and so on.

once again, the intake is not needed at all lol zero gains at that mod level too. k and n claims 5 hp, thats not gonna happen. its a lie.

if you want one, make your own for cheap. all it is, is that sound......

**04lss** · 09-26-2014

my understanding is that stock hp is 240 at the crank, 19-200 at the wheels

**Scottydoggs** · 09-26-2014

rockers cant hurt, not cheap once again, or a cam, also not cheap.

anything smaller then the 3.4 and the corn you should start thinking transmission, cause its gonna blow up.

my set up is maybe a 30 hp gain. not 100% sure tho. it defiantly moves better.

not sure if you can see my sig or not. but ive got----1.95 rockers, headers, 3.4 and tuned.

**tomtom123** · 09-26-2014

04lss, see my post on FullThrottle?
I gave a decent bit of info on modding these engines.
Search these forums for Safely Modding Your 3800. Very good info =)

http://www.grandprixforums.net/showthread.php?t=17482
Safely Modding Your 3800 Powered Car!!

**SnowFlake** · 09-26-2014

Originally Posted by Scottydoggs

those are stock dyno #. there is zero gains form a intake. snake oil..........

Originally Posted by Scottydoggs

headers take power away unless you pulley down. i went from 7 psi stock, to headers and 5.3 psi of boost.

car felt better off the line. but thats it with headers.

Both of these comments are entirely false.
Stock L67's make 180-190whp, not 223whp.
Headers usually add 15-20whp without a tune or a pulley.

I've had dozens of these cars on a dynojet. To say they lose power with headers is ludicrous.

**Impala131** · 09-26-2014

Originally Posted by SnowFlake

Both of these comments are entirely false.
Stock L67's make 180-190whp, not 223whp.
Headers usually add 15-20whp without a tune or a pulley.

I've had dozens of these cars on a dynojet. To say they lose power with headers is ludicrous.

I've "felt like" I lost some low end when I added headers with stock pulley, but gained a good chunk of top end. No dyno numbers to verify this, though.

**blueguy** · 09-26-2014

Originally Posted by SnowFlake

Both of these comments are entirely false.
Stock L67's make 180-190whp, not 223whp.
Headers usually add 15-20whp without a tune or a pulley.

I've had dozens of these cars on a dynojet. To say they lose power with headers is ludicrous.

Hell froze over...

Because this is correct.

If your stock L67 car makes 200WHP or more, you'll be lucky.

Adding headers lowers boost numbers because the car is flowing more freely...you then add the pulley to make up for the loss, because all it is doing is shifting the power up...you're not losing ANY power, and it's easier to launch because the torque is now geared a little higher in the band.

HiPo Pontiac did a test I think on an SSEi back in the day, and it gained close to 30WTQ and north of 20WHP. L36 gains were close as well...because I think they tested a GP GT too, just to compare...and to show how crappy and restrictive the manifolds to the catback really are.

**04lss** · 09-26-2014

Originally Posted by blueguy

Hell froze over...

Because this is correct.

If your stock L67 car makes 200WHP or more, you'll be lucky.

Adding headers lowers boost numbers because the car is flowing more freely...you then add the pulley to make up for the loss, because all it is doing is shifting the power up...you're not losing ANY power, and it's easier to launch because the torque is now geared a little higher in the band.

HiPo Pontiac did a test I think on an SSEi back in the day, and it gained close to 30WTQ and north of 20WHP. L36 gains were close as well...because I think they tested a GP GT too, just to compare...and to show how crappy and restrictive the manifolds to the catback really are.

So am i actually making more power with headers on a stock gtp, and moving the power band, or is the powerband just moving without creating power?

Im talking staying on a stock pully,
i know if i drop a pulley size to like a 3.5 with headers it adds power.

**Scottydoggs** · 09-26-2014

you loose boost for sure, it did gain power off the line i said, ( headers will let it melt the tires) but its no faster then stock to me. till you add a smaller pulley. butt dyno

and the intake dont add those numbers, you know that.

and thats crank HP as the dealer would post it. not to the wheels.