[tscdennab]

Originally Posted by packinDSS

Are you sure they gave you S2?

What do you mean by "homemade" 2.5 inch downpipes? Clarify what you did. Cat off cats welded peices in etc.....

Yes, the boost indicates they gave me GIAC S2.

My downpipes are made from OEM downpipes with cats cut off and replaced with 2.5" pipe.

[tscdennab]

Originally Posted by Clap135

So you guys are under the impression that a dci and exhaust is going to give him 30-40 whp?
I was under the impression that GIAC works off load targets and adjust boost to meet those targets.

Did anybody miss the fact that he is hitting 481 wtq? That is a crazy high number.
390wtq on the stock tune? Seems like this dyno is a little messed up to begin with.

The torque is in Nm, and not lb-fts

In fact, things do seem to point out that there is an airflow starvation at higher RPMs.

As far as I know, on a dyno the power is calculated from torque and RPM.

The fact that the GIAC advertised torque is (almost) reached indicates that the problem is at higher RPMs and not on the entire power band. In my opinion this is also indicative of inadequate airflow and - maybe - restrictive exhaust.

We'll see tomorrow

[Clap135]

So just to clarify everyone is blaming the numbers on the exhaust and intake? That's a little hard to swallow.

[themyst]

These mustang dynos load the hell out of fourth gear, even longer than what the normal 4th gear pull on the street would be.

I'm with Clap, that dyno is messed up. Get on a Dynojet to compare numbers and see where you stand amongst other dyno results.

[Jeff@TopGearSolutions]

I do agree an intake and full exhaust is not finding the power that is lost. However intakes do help over 13 PSI just not 20-40WHP.

To bad you cant datalog.....

Boost leak?

[tscdennab]

UPDATE: After re-dynoing with Injen intake, I obtained an extra 11whp (delta between WCF corrected values), making it a 74whp delta (graph below). 27 more to go...

I have added the graph on the first post.

[BrianMN]

Even though youve made your stock downpipes into "2.5" catless dps", I would think they are still at a big disadvantage over real downpipes...which would explain a bit more wgdc and less power.

[tscdennab]

Originally Posted by BrianMN

Even though youve made your stock downpipes into "2.5" catless dps", I would think they are still at a big disadvantage over real downpipes...which would explain a bit more wgdc and less power.

Can't really see why but I definitely have in plan to purchase some 3" downpipes.

[Penn999]

Originally Posted by BrianMN

Even though youve made your stock downpipes into "2.5" catless dps", I would think they are still at a big disadvantage over real downpipes...which would explain a bit more wgdc and less power.

+1, he needs to grab some ar's and he will c that power he is looking for. Flow is probably bottlenecking at the stock downpipes.

EDIT: its also not all about the size diff. from 2.5 to 3. Its about the air being able to "freely flow." The can imagine that the flow rates on the stockers are a lot worse because of the design. When the air flows out where the cats used to be, it disrupts "smooth" airflow. The straight pipes will helpalleviate that which should translate into more HP

[Big Tom]

Originally Posted by tscdennab

Can't really see why but I definitely have in plan to purchase some 3" downpipes.

You will not notice any difference IRL. Trust me on that.
I have the fastest N54 in Sweden, and I'm the only one running with 2.5" DP's.

[R1000K3]

Originally Posted by Big Tom

You will not notice any difference IRL. Trust me on that.
I have the fastest N54 in Sweden, and I'm the only one running with 2.5" DP's.

I hope that is part of the history next year

Happy Christmas

[tscdennab]

Originally Posted by Big Tom

I have the fastest N54 in Sweden, and I'm the only one running with 2.5" DP's.

This doesn't count, maybe you are also running the most boost ? I need every bit of help possible in order to maximize power at the ~16psi. I'm not saying that 3" is better than 2.5", but I did read the Mr.5 comparison between them and can't help to consider switching...

[BrianMN]

Originally Posted by tscdennab

Can't really see why but I definitely have in plan to purchase some 3" downpipes.

Not surprised.

Look at how the exhaust is flowing through your downpipes. It's not the diameter, it's the route.

[BrianMN]

Originally Posted by Big Tom

You will not notice any difference IRL. Trust me on that.
I have the fastest N54 in Sweden, and I'm the only one running with 2.5" DP's.

We aren't comparing 2.5" dps to 3"dps...we're comparing homemade stock downpipes with the cats cut out of them vs. an actual set of aftermarket downpipes.

What "tscdennab" has are NOT 2.5" downpipes.

[Penn999]

Originally Posted by tscdennab

This doesn't count, maybe you are also running the most boost ? I need every bit of help possible in order to maximize power at the ~16psi. I'm not saying that 3" is better than 2.5", but I did read the Mr.5 comparison between them and can't help to consider switching...

+1, just bc he is the fastest doesnt mean that its the best or that its a proper setup to run. I can put in No2 and run 100% meth or just bump up the psi slightly higher than the guy im racing(even tho its not safe) and be one of the fastest over here... Also you cannot tell me that flow is better through pipes that are smaller in diameter and have a disruptive flow pattern, thats basic physics and to deny that is only stupid IMO. I know you(big tom) dont like to spend money and think that your DIY mods are better but Im sure that dzenno or enrita would burn you up, especially after dzenno gets his RB's installed. To say that you are the fastest 335i in sweeden means nothing to me, put down some 1/4 miles times and 60-130 times and compare them to the rest in the WORLD.

[Penn999]

Originally Posted by BrianMN

Not surprised.

Look at how the exhaust is flowing through your downpipes. It's not the diameter, it's the route.

THANK YOU! someone with some sense...

[packinDSS]

Originally Posted by BrianMN

Even though youve made your stock downpipes into "2.5" catless dps", I would think they are still at a big disadvantage over real downpipes...which would explain a bit more wgdc and less power.

I agree. Get a set of 3 inch pipes. Take a look at the PLM ones that are posted before you spend 600 or 700 on shiney show price pipes........ the plm can be had for 300 and they are 3 inch. Read the thread before you buy. Pipes brands can be as bias as Procede and JB in here.....cough cough

I like that you went with homemade pipes but I know that they wont Flow like real catless versions. Down pipes are the biggest power gain you can do. At higher boost they become more important then ever.

[packinDSS]

As for 2.5 vs 3inch I do believe like most people that the 3inch make more power. The amount of hp/tq is highly debatable........but consider that the raceland 2.5inch pipes can be had for $200 and the 3inch PLM for $300. I'd recommend spending the extra $100 on the 3inch even if its only worth 7hp more which again is debatable. As we continue to mod our cars the 3inch version will yeild more power.

[Jeff@TopGearSolutions]

Originally Posted by BrianMN

We aren't comparing 2.5" dps to 3"dps...we're comparing homemade stock downpipes with the cats cut out of them vs. an actual set of aftermarket downpipes.

What "tscdennab" has are NOT 2.5" downpipes.

OHHHHH thats a lot different then.

REal 3 inch DP will show an advantage.

I would be impressed to see the 27. But we'll see.

Originally Posted by packinDSS

I agree. Get a set of 3 inch pipes. Take a look at the PLM ones that are posted before you spend 600 or 700 on shiney show price pipes........ the plm can be had for 300 and they are 3 inch. Read the thread before you buy. Pipes brands can be as bias as Procede and JB in here.....cough cough

I like that you went with homemade pipes but I know that they wont Flow like real catless versions. Down pipes are the biggest power gain you can do. At higher boost they become more important then ever.

Oh no, you didnt

[packinDSS]

Ill bet there worth a minimum of 20hp

[Jeff@TopGearSolutions]

Only reason im skeptical is cause a guy i know had

tune meth DCI @ 17 psi

with the addition of intercooler and dp's he made another 13 WHP with both.

with addition of another 1 PSI made a total gain of 24WHP.

These cars are inconsistent though. So really none of this holds water. Im a realist.

[BrianMN]

Originally Posted by JPSlick

\These cars are inconsistent though. So really none of this holds water. Im a realist.

+1. Inconsistency killed the radio star.