Dynamometer Results & Comparisons - Results are in on my 370 build!!!!!!!!! Not so good IMO

And I am at a cross roads. My tuner and I where left scratching our heads.
414 was all it put down.

M6 car, Ford 8.8 with 4:30 gears. 370 with wiseco flat tops. .040 head gasket
stock crank. comp should be around 11.6:1. Bosch 42 lbs injectors, walbro 255 pump, comp 240 244 608 612 on 112 lsa cam, Patriot cnc'd 243's milled to 59cc matched ported to intake gaskets by me, Professional Products 96mm intake matched ported to gasket, 101mm tb, 95mm maf, 1 3/4 long tubes with ory pipe going into a flow master. I think that about does it. I've got a mismatch somewhere. Something is not jiving in this set up. Had good A/F ratio through out pull. But at about 5500 it started seeing vacuum.

Anybody got any good insight on what might be the deal. I might have to scratch the whole top end and and go another route. Could it be the cam?
Had no issues with fuel flow or duty cycle on injectors. They were running at 60% at WOT. Just kinda need some constructive opinions and thoughts from experienced people. Thanks

BTW, peeps go out to my new tuner - jonCR96Z. He got it running great. Can't say so much for another shop in Randleman. If your in the area, hit him up and he'll do you right.

That intake is a leaky pos, ditch it. Drop that and the flowmaster and it should pick up quite a bit.

That's what I was thinking about the intake; junk..... I was also thinking cut outs and leave the flow. It sounds to good to replace it. It just got broken in real good. LOL.....

That intake is a leaky pos, ditch it. Drop that and the flowmaster and it should pick up quite a bit.

+ a ton. That Flowmaster Sucks and the PP IM is also a hunk of poo.

How much torque did it make?

I would ditch the Flowmaster period. With a cutout you will have to open it for power and then it will sound like crap. A good flowing, good sounding exhaust is better than a cutout.

Not sure what you mean by "breaking in" since it is welded baffles...there is nothing to break in.

What lid do you have on the car? Or some other kind of filter?

Cut the flowmaster off. I've had a 390 rwhp cam only car pick up 38 by cutting it off, 470 rwhp GTO picked up 73 by cutting it off, etc. See it all the time while tuning. Customers can't believe it. :D

i think u got some good info to start with, better exhaust and ditch the manifold should get you back on track, what kind of tq did u put down?

1st bypass the muffler and see how it does, next Id lose the intake and go fast. Im willing to bet that alone will put you around 450.

It blows my mind that people still to this day install flowmaster catbacks on F-bodies when there is a wealth of info out there about how restrictive they are.

Anyway. You're probably losing 25rwhp at least through the muffler. Fixed that problem and replace that POS manifold, and you should be in the 440-450 range. That's about what a 370ci is going to make with Patriot heads on it.

Good luck.

Get rid of the flowdisaster....

It blows my mind that people still to this day install flow master catbacks on F-bodies when there is a wealth of info out there about how restrictive they are.

Anyway. You're probably losing 25rwhp at least through the muffler. Fixed that problem and replace that POS manifold, and you should be in the 440-450 range. That's about what a 370ci is going to make with Patriot heads on it.

Good luck.

I was really thinking of getting a loudmouth when I bought this car. The flow was already on it when I got it. What would be yall's choice for the exhaust? Duals is out of the equation right now. Give me some thoughts. Fast 92, 102, use the 101 TB I have or get a fast 92/92? What combo would you guys run?
And thanks for the input..

If you can't do duals the only semi-permanent compromise I would run on a car I owned would be 3" y into a good merge to single 4" with a good muffler. Still have that crappy y pipe sound but at least it would flow.

Loudmouth does not sound good at all on a modded car.

put a cutout on it.. if you love your blowblaster all that much..

FAST 102 and duals, why are they not an option?

+10 with everyone above about the Flowmater and Intake..
Another thing will help is 1.7/8 headers (Check TSP 1.7/8 headers for great price and power.

I have a friend gained 38rwhp 21rwtq going from flowmaster to open Y-pipe on cam only F-body I did the dyno myself I couldnt believe it. :D

It blows my mind that people still to this day install flowmaster catbacks on F-bodies when there is a wealth of info out there about how restrictive they are.

Anyway. You're probably losing 25rwhp at least through the muffler. Fixed that problem and replace that POS manifold, and you should be in the 440-450 range. That's about what a 370ci is going to make with Patriot heads on it.

Good luck.

Hahahahahaha, everyone that i know calls it the "chokemaster"...:burn:

FAST 102 and duals, why are they not an option?

Well, the last time I checked they were not free. But if you want to buy them for me, I'll pm you my address and you can drop ship them to my house if you would like. LOL. This car hasn't nickled and dimed me to death it's been more like 500 and thousand. The wife is not going to go for no 1800.00 for exhaust. I just dumped 1200 in some meats for the back and front. I'll just have to start saving some mad cash back until I get enough saved up to get some duals and run the muffler I have now. One thing for sure it may choke it to death but it does sound good. never had a negative comment about the sound. But sound don't move it down the road and make good numbers, so it's gotta go........

Just install a cutout and keep your flowmaster

Just install a cutout and keep your flowmaster $200 a piece vs $400 for catback is a no brainer

ANY FAST intake, true duals, 1 7/8 primaries, and a patient retune will pile on 50rwhp and probably as much torque. Those big pipes on the intake side will work out well but will take a good and diligent tuner to sort out. You have a badly mismatched combo on the external pieces.

The wife is not going to go for no 1800.00 for exhaust.

What the hell exhaust is $1800? You could go to the muffler shop, cut the flowmaster out, and weld in a better muffler for $150 or less I would think.


Just install a cutout and keep your flowmaster $200 a piece vs $400 for catback is a no brainer

I can't understand the logic if the long term goal for the car is power, either street or strip. There are plenty of exhaust setups which will sound as good or better than the flowmaster and not rob power. Cutouts sound pretty bad (my car has them for the track).


If the goal for this car is at all performance oriented, I would find a used set of TSP duals and put them on the car next chance you get. Should be $300-400 and you won't ever have to mess with it again. Just don't get tricked into buying one of the ones from the bad batch of x pipes.

^^ I agree with you but it seems like OP was on a budget that's why I recommended cutout for now so he can keep the flowmaster and open the cutout when he wants to get on it

What the hell exhaust is $1800? You could go to the muffler shop, cut the flowmaster out, and weld in a better muffler for $150 or less I would think.




I can't understand the logic if the long term goal for the car is power, either street or strip. There are plenty of exhaust setups which will sound as good or better than the flowmaster and not rob power. Cutouts sound pretty bad (my car has them for the track).


If the goal for this car is at all performance oriented, I would find a used set of TSP duals and put them on the car next chance you get. Should be $300-400 and you won't ever have to mess with it again. Just don't get tricked into buying one of the ones from the bad batch of x pipes.

kooks true dual exhaust kit is 1800.00, that's what the ----. I really don't want a dump exhaust; being it is a T/A. Look kinda stupid with out no tips.

I think he was reffering to cat back exhaust like borla, magnaflow, gmmg etc that flows way better than flowmaster with the same or better sound, those can be found for $300-$500

I was really thinking of getting a loudmouth when I bought this car. The flow was already on it when I got it. What would be yall's choice for the exhaust? Duals is out of the equation right now. Give me some thoughts. Fast 92, 102, use the 101 TB I have or get a fast 92/92? What combo would you guys run?
And thanks for the input..



I like magnaflow... They are cheap, stainless steel and have a lifetime warranty. They only make a fast 102 right now. I bet you pick up 50+ by doing those 2 mods.

kooks true dual exhaust kit is 1800.00, that's what the ----. I really don't want a dump exhaust; being it is a T/A. Look kinda stupid with out no tips.

Fair enough, the Kooks system is so expensive it's off my radar.

There are other options for duals such as fabricated over the axle, under the axle, or dumps with dummy tips in the bumper.

Or a good flowing y pipe merge with a good muffler and you can even sell your Flowmaster to offset costs.

And of course the other option is a manual cutout or electric cutout. Fbodies are low enough manual ones are hard to uncap and electric ones cost as much as a good exhaust.

You could also try just pulling the flowmaster on the dyno to confirm that is really the problem before spending money.

Hey guys,

Don't mean to usurp the OP's thread but I have a dyno tune date this summer as well. I'm also running a flowmaster catback. I knew these weren't the best exhausts but I loved the sound of my 80 series on the old engine and everyone who hears my new LT1 mill with this 3" american thunder says it sounds awesome. I love it, and yes I know I'm leaving power on the table.

But do you guys really think a chokey muffler could tie up as much as 30 RWHP? Again I knew this exhaust wasn't the best which is one reason I decided to ditch the cat and go with an ORY to try and balance things out. But hell, now I'm starting to consider adding a cutout myself before dyno day.... :S

THIRTY RWHP over a freakin muffler??? I have a hard time believing any product (or company) could continue to exist if it were really that bad.

I've seen a shitty air filter eat up 30rwhp.. Their for sound not performance.. U can just throw a cutout on it for minimal $$$ and have best of both worlds..

THIRTY RWHP over a freakin muffler??? I have a hard time believing any product (or company) could continue to exist if it were really that bad.

Normal flowmasters are not a problem, it is the crossflow catback design for f bodies that is junk.

As for the part about staying in business, regardless of how common knowledge it is on some sites they are junk and the advice people on this site give to not use them...they are still getting bought and installed. Often at the fault of previous owners and sometimes because people choose to sacrifice for that tone.

There are a lot of crap products on the market because people don't fully educate themselves before they purchase (ie most fuel/oil additives, K&N filters, throttle body spacers, Tornado intake improvers, MSD coil packs for ls1, most hand held tuners, etc). Marketing is a powerful tool.

Hmm, where have I heard this all before???

http://ls1tech.com/forums/dynamometer-results-comparisons/1505954-383-ls6-does-look-right.html

;)

I wouldn't worry so much about chassis dyno's, they are a tool for tuning, not presenting real hp numbers. Engine dyno's are more accurate, but still just a tool to tuning.

for example.. my Mustang weighs 2920lbs and on the dyno, it only put 330hp to the wheels through my Jerico 4 spd.
Went to the track and it just ran a 9.14@148 with a 1.31 60ft. It's only about 450hp off the real hp numbers.

I agree that a cutout would be cheap and easy to rule out the exhaust and I wouldn't have that intake on any car that I owned.


How much torque did it make?
The rpm lead is messed up on the dyno, so it can't calculate the torque number. Just gives a HP vs MPH graph.


THIRTY RWHP over a freakin muffler??? I have a hard time believing any product (or company) could continue to exist if it were really that bad.

Not saying that it will gain 30 (it could though), but I had a set of Corsa clone exhaust tips installed on my car and the shop that did it used 2 1/4 pipe to mate them to my Magnaflow catback (just the straight part of the pipe, not the bend). I knew it wasn't helping but I didn't figure it was hurting me that much. I finally broke down and cut the tips off while my car was strapped down on the dyno and it gained 10rwhp (396 rwhp total) from just removing the tips.

I wouldn't worry so much about chassis dyno's, they are a tool for tuning, not presenting real hp numbers. Engine dyno's are more accurate, but still just a tool to tuning.


The dyno is just a tuning tool, but I use this particular dyno quite a bit and it always has very consistant results with what most cars dyno with similar mods. Even 346 A4 cars with less mods make more power than this car on the same dyno.

You have to take that for what it is and not just accept that maybe it just doesn't show good power on the dyno. Something is not right somewhere.

The cheapest and easiest way to fix your problem is to install a cut out. That way if your just cruising around keep it closed, and the car isn't so loud. Then when it's time to race open that byatch up and gain that lost power back lol.

I'll do a search for it but as far as the dozens of eBay auctions for cut outs go, are they all the same? There are tons for sale for around $200 +/-.

How much do you have to spend for a decent unit? Do the more expensive ones open faster or what? lol

if you want to go the super cheap route, get a cutout with a block off plate that usues 3 bolt header gaskets and nuts/bolts. I had one on my truck since I didnt open it that often and I had decent ground clearance to get them off. They are only like 30 bucks and took at most 5 minutes to pull/install

Sorry I was talking e-cutout. I wouldn't consider a manual. I see the DMH units around $200, same as all the stuff on ebay.

I'm wondering how well these e-cutouts seal. i saw a video close up of one opening and then closing and once it closed and the engine was still being reved you could still see the exhaust condensation stipping out of the closed e-cutout... I'm not running any cat and the slightest of leaks from the exuast in the past has completely stunk up the cabin. Anyone with an e-cutout have issues with how well they seal when closed?

kooks true dual exhaust kit is 1800.00, that's what the ----. I really don't want a dump exhaust; being it is a T/A. Look kinda stupid with out no tips.

Then put dummy tips on it or run the TSPs under the axle. No one really knows how much duals help until they swap them in.

UUUmmmmm why did you see vacuum at 5500 rpm? Thats crazy! Wide open is wide open. What do you guys think?

UUUmmmmm why did you see vacuum at 5500 rpm? Thats crazy! Wide open is wide open. What do you guys think?

If the engine wants more air than it can get, that's vacuum. It wasn't a lot of vacuum but it's more than I normally see on the dyno.

Get rid of the chokemaster...bingo!!

If your seeing vacuum at wot, it wants more air. Get a better intake.

Also, let me throw this out there. When you put the new pistonp in, did you have the crank balanced? An un balanced rotating assembley will eat up a ton of power and kill your motor in a hurry.

Hey guys,

Don't mean to usurp the OP's thread but I have a dyno tune date this summer as well. I'm also running a flowmaster catback. I knew these weren't the best exhausts but I loved the sound of my 80 series on the old engine and everyone who hears my new LT1 mill with this 3" american thunder says it sounds awesome. I love it, and yes I know I'm leaving power on the table.

But do you guys really think a chokey muffler could tie up as much as 30 RWHP? Again I knew this exhaust wasn't the best which is one reason I decided to ditch the cat and go with an ORY to try and balance things out. But hell, now I'm starting to consider adding a cutout myself before dyno day.... :S

THIRTY RWHP over a freakin muffler??? I have a hard time believing any product (or company) could continue to exist if it were really that bad.

A cutout was worth 1 tenth and 1 mph at the track on back to back passes over a Flowmaster. That was on a bolt-on LT1, so it would probably be more restrictive on a higher hp setup. I agree though that 30 rwhp sounds high.

My brother gained 9 rwhp with a cutout over his Magnaflow catback on his 400 rwhp Z28.

Does anyone have back to back comparisons of a Flowmaster vs Magnaflow or another main stream catback? Alot of people compare the Flowmaster to cutouts or open y-pipes, etc, but I never see heads up comparisons with other systems.