BigHawaii CAI project

[HDVa]

Originally Posted by AaronC

Most modifications (naturally aspirated) are gonna make the biggest difference in the mid range to top end. There's not much you can do to help the "low end". Outside of a supercharger or more cubes and compression, you aren't gonna see gains below 3000 RPM's. I don't see why everyone is so facinated with power that low anyway? If you want power at low RPM's for cruising and tip in throttle, then you bought the wrong truck. That's why they make Turbo Diesels. It's easy to add power anywhere in the powerband with them. With that said, I don't think you'll lose anything below 3k RPMs with these most basic of bolt ons. It should just make the power band less peaky and have more balance (avg power) across the tach. Running from a dead stop is the only time you'll be below 3k RPM's anyway. Even with that, you have plenty of gear in first to get the RPM's up. If you stomp the gas from a roll the truck is gonna downshift and the RPM's go way up again. Also that 10-15 hp gain on a truck that runs mid 15's in a 1/4 mile will make a much bigger difference than that same 10-15 hp on a car that runs 10's.

I just wanted to clear a couple of things up concerning your comments.

1) "If you want power at low RPM's for cruising and tip in throttle, then you bought the wrong truck. That's why they make Turbo Diesels." The Titan makes great torque from 1500 - 2500 RPMs with the stock exhaust. This is not only great from the start but it is where this truck normally revs during regular cruising speeds (not during acceleration) , and it certainly affects how well the truck tows without having to downshift. We want power at the low end, and for a gas engine, the Titan delivers. We've felt it, and we want to continue having it.

2) "Running from a dead stop is the only time you'll be below 3k RPM's anyway". See #1.

You are certainly correct that diesels make better power at lower RPMs, but then they make better power across their whole operating range. Folks who buy Titans have the choice, and they opted to go with the best new gasoline truck that has come out in recent memory, and yes, they want to have their cake and eat it too.

[AaronC]

Originally Posted by HDVa

I just wanted to clear a couple of things up concerning your comments.

1) "If you want power at low RPM's for cruising and tip in throttle, then you bought the wrong truck. That's why they make Turbo Diesels." The Titan makes great torque from 1500 - 2500 RPMs with the stock exhaust. This is not only great from the start but it is where this truck normally revs during regular cruising speeds (not during acceleration) , and it certainly affects how well the truck tows without having to downshift. We want power at the low end, and for a gas engine, the Titan delivers. We've felt it, and we want to continue having it.

2) "Running from a dead stop is the only time you'll be below 3k RPM's anyway". See #1.

You are certainly correct that diesels make better power at lower RPMs, but then they make better power across their whole operating range. Folks who buy Titans have the choice, and they opted to go with the best new gasoline truck that has come out in recent memory, and yes, they want to have their cake and eat it too.

I've driven a Titan so I know what they feel like. They are very responsive for a truck. But how are you gonna feel any power let alone a power change from modifications if the truck is at a set cruising speed/rpm? A blower won't make boost at cruise, nor will a turbo, and nitrous only works at WOT. The only time you'll feel a change is under load which is why I mentioned the gearing break down. Also if you're towing anything significant, you won't be towing it at 1500-2500 RPM nor in overdrive.

[bestatchess]

"I don't think you'll lose anything below 3k RPMs with these most basic of bolt ons."

It is very common to lose low end with after-market exhausts.

"It should just make the power band less peaky and have more balance (avg power) across the tach."

I haven't seen any dyno sheets showing anything but high RPM gains.

"Running from a dead stop is the only time you'll be below 3k RPM's anyway."

I spend 95% of my time below 3K RPM.

"Also that 10-15 hp gain on a truck that runs mid 15's in a 1/4 mile will make a much bigger difference than that same 10-15 hp on a car that runs 10's."

Not true, unless the car weighs more than the Titan. Since the car will likely weigh alot less than the Titan the 10-15 hp will make a bigger difference on the car.

[Sammy Sandbag]

Um, I drove 1,000 miles this weekend at 85mph and never got over 2,000rpm except for accelerating on the on ramps.

[AaronC]

Originally Posted by bestatchess

"I don't think you'll lose anything below 3k RPMs with these most basic of bolt ons."

It is very common to lose low end with after-market exhausts.

"It should just make the power band less peaky and have more balance (avg power) across the tach."

I haven't seen any dyno sheets showing anything but high RPM gains.

"Running from a dead stop is the only time you'll be below 3k RPM's anyway."

I spend 95% of my time below 3K RPM.

"Also that 10-15 hp gain on a truck that runs mid 15's in a 1/4 mile will make a much bigger difference than that same 10-15 hp on a car that runs 10's."

Not true, unless the car weighs more than the Titan. Since the car will likely weigh alot less than the Titan the 10-15 hp will make a bigger difference on the car.

I've done just about every mod to my 5.0 liter mustang and never noticed a loss of low end with exhaust mods. Guess what, the 5.0 was a truck motor too, lol. They all said the same things on their boards 8 years ago. I'm very familiar with modifying all kinds of cars. But, I think you guys are missing my point. The point is that you will never notice any power differences while at a cruising speed. Guess what, I still drive my mustang at less than 3k rpms 95% of the time too. Other than the thump from my cam, I cannot notice any difference while cruising at 70 mph on the freeway than I did stock. My point is that accellerating is the only time power is felt which is why I talked about the RPM and gearing. When you're done accelerating the truck will shift and go back to cruising RPM's. And the faster you go the more power it takes to accelerate a car or truck. I've seen this many times over at the dragstrip in the last 10 years. The slower the car, the easier it is to gain ET/MPH with less power regardless of weight. A 15/16 second car is a 15/16 second car regardless of it's weight or power. Nitrous is the perfect example. Bolt on a 100 shot to a Titan and I'll bet $$$ that it'll gain more ET/MPH than a 10 sec car. Again, seen it many times. Please do not tell me anymore how much you cruise around at such low RPM's. I already understand that. I do it too. But you will never notice a power change at any given cruise speed. Just like my blower example. Cruise around at 70 on the freeway making 0 psi, and the truck will feel no different and make no more power than stock. Stick your foot on the gas, and yes you will feel the massive difference for that 5% or so of the time you accelerate. I hope I clarified things as much as possible.

[Sammy Sandbag]

Aaron, I think everyone (including myself) chimed in because you said "Running from a dead stop is the only time you'll be below 3k RPM's anyway." which is a bit contradictory to the rest of your statements. Exahaust modifications can easily cause a loss of low end performance due to loss of scavenging, it's well known.

[Truck41]

i hope you are a nascar mechanic, because if you're not, then i not driving a big green titan, and it has power from the get go to the got get, and i use it all, how soon we forget.

[AaronC]

Originally Posted by sammy sandbag

Aaron, I think everyone (including myself) chimed in because you said "Running from a dead stop is the only time you'll be below 3k RPM's anyway." which is a bit contradictory to the rest of your statements. Exahaust modifications can easily cause a loss of low end performance due to loss of scavenging, it's well known.

Ah, but it was in the context of accelerating vs. cruising. You won't be accelerating very well between 1500-3000 RPM is what I was meaning. At least not in the context of noticing power differences of a gain or loss. Sorry I wasn't more clear. I'm very familiar with exhaust mods as I have friends with many different makes and models so I know what they can and don't do. And what you describe above is incorrect. Exhaust sytems increase scavenging and reduce pumping losses.

You guys won't see a dyno sheet from a Titan that starts where you want to see it (1500-3000). At least not a chassis dyno. The auto tranny isn't gonna allow it. I just think people's expectations on this board are VERY unrealistic. If you're happy with the truck then leave it alone. Especially when everyone is so emphatic about cruising it around. No mods should be needed to putt around town or on the freeway.

I'm not a nascar mechanic, just a tech nut and car enthusiast. I feast for performance, which is why this was my first forum to visit on this site. I happened to be looking into a Titan for a daily driver/ work truck (towing) and was comparing it to the Ford F250 V10 and Diesel. The modification bug will ultimitalely bite me no matter what I purchase, I just thought I'd find out what was currently available and what would be. I thought the Titan I drove was awesome. I like Nissan's products as I drive an 03 Maxima 6 spd. on a daily basis. They are a hard company to beat right now in regards of what you get for the $$$ you pay.

[Sammy Sandbag]

And what you describe above is incorrect. Exhaust sytems increase scavenging and reduce pumping losses.

You say one thing, fluid dynamics say another. I'd stay away from the V-10.

[37L1]

AaronC,

Thanks for your informative posts, and welcome to this forum.

Hope you choose to go TITAN, you won't regret it!!!

And if you do, please keep us informed when the mod-bug bites,

Thanks,

37L1

[bighawaii]

Originally Posted by pciley

WOW! This CAI thread sure changed course... I started reading out of curiosity for BigHI's cut and fab project. Anxious to see the results

Now I have to ask after reading the exhaust discussion here... I have the Banks CB and am ready for headers NOW. I am not much of a waiter, Banks might take months. I find the JBA headers' price appealing, but I don't want to make the mistake of buying a pair of headers that were meant for JBA's exhaust system.
Obviously, my question is will the two different brands' exhaust components compliment eachother? specifically, I am hoping the headers will give more power to the low end where the Banks seems to divert more attention to the high end.
Secondly, I have looked at the top of the engine trying to decide how hard it would be to put the headers on myself. It looks like a BIT$@ !! Has anyone here put headers on a Titan themselves?

BigHI, if your project is successful, maybe you can beat AEM to the market and mass-produce your intake modification for that attractive price of $70. I will be looking for it on Ebay soon! Good luck

shorty headers tend to add to mid-top end power, so adding JBA's shorties even with their "firecone" collector to a already high flow cat-back will not help with your low end. if you really want headers fast you can ask a reputable muffler shop to make you a set of full legnth headers, they will help preserve your low end and add a bit more mid.
im still waiting for my air-filter which is supposed to be here any day now. anyone can buy a similar or same filter if they dare to hack their box. ill post diagrams with measurements of my heatshield for others. i just got my flowmaster 70 series si/so and will install it tomorrow. the intake and muffler combo should make my titan "sound" mean but not obnoxious. after headers then the beast's power tuning will "probably" be complete and im off to my serious hp project, a twin turbo'd ls1 in a puny s-10.

[bighawaii]

"Also that 10-15 hp gain on a truck that runs mid 15's in a 1/4 mile will make a much bigger difference than that same 10-15 hp on a car that runs 10's."

bestatchess is right when he said
"Not true, unless the car weighs more than the Titan. Since the car will likely weigh alot less than the Titan the 10-15 hp will make a bigger difference on the car."

15hp will definantly affect a 3000lb drag car more then a 5000lb truck. think about it, your adding the same amount of hp to a vehicle that weighs less.

[bighawaii]

Originally Posted by AaronC

I've driven a Titan so I know what they feel like. They are very responsive for a truck. But how are you gonna feel any power let alone a power change from modifications if the truck is at a set cruising speed/rpm? A blower won't make boost at cruise, nor will a turbo, and nitrous only works at WOT. The only time you'll feel a change is under load which is why I mentioned the gearing break down. Also if you're towing anything significant, you won't be towing it at 1500-2500 RPM nor in overdrive.

i think hes trying to say, the lighter the trottle load the the less the gain expected. this is true. a 15hp increase with a cat-back doesnt really put a dent in the titans 5000lb weight or 1/4, mabe a few hundreths of a sec. weather conditions will most likely play a bigger role. so that same 15hp at less then full-trottle conditions, say at 15% load (random low number) will have a even lesser effect. its facinating how sensitive some peoples "butt dyno " is lol.
the actual scavenging efficiency of say a banks over a stock muffler at certain loads, say at 15% load and lower rpms like 1500, will not be as noticable either. you may even have a slight loss, which is barely noticable...some extremely sensitve butt dynos may but who knows the factors there lol.

[kmfernandez]

Originally Posted by bighawaii

"Also that 10-15 hp gain on a truck that runs mid 15's in a 1/4 mile will make a much bigger difference than that same 10-15 hp on a car that runs 10's."

bestatchess is right when he said
"Not true, unless the car weighs more than the Titan. Since the car will likely weigh alot less than the Titan the 10-15 hp will make a bigger difference on the car."

15hp will definantly affect a 3000lb drag car more then a 5000lb truck. think about it, your adding the same amount of hp to a vehicle that weighs less.

The way I read it aaronC was comparing a truck running mid 15s vs a comparable vehicle that is running 10s. The implication being that the one running 10s is dang near all tricked out already, and the one running 15's is not. So the fast one just can't go much faster, but the slower one has room for improvement so what he wrote makes sense.

[AaronC]

My analogy of 10-15 HP is for a car with timeslips. It doesn't matter if the car weighed 6000 lbs or 1000 lbs. If it ran 15.5, it ran 15.5 so weight isn't an issue. Add 10-15 HP to it (15.5 vehicle) and it could show a gain of .25-.30 in ET and 2-3 MPH in trap speeds. Add the same to a 10 sec car running 125-130 MPH and it might add .05-.10. The faster you go the more power it takes. Look what it takes for a Titan to go down the quarter mile stock. If you double the power does it go down the track twice as fast (ET/MPH wise)? How about triple its power? How much would it take to make it run 7.75 seconds in a 1/4 (approx 1/2 of stock)? As you can see it will take a whole lot less (% wise) to make it go from 15.5 to 15.2. I learned this from my own vehicle. Now it takes a lot more power to gain each .10 and MPH than it did when stock.


Thanks for the welcome 37L1

kmfernandez- You hit the nail on the head!