JClaw

iTrader: (17)

Title says it all. I heard that it's better to have a little restriction than have something too big. I should have about 250whp. I am sure that the 2.5" I have is fine for that amount, but how much could I make with a 2.5" system without having too much restriction?

Jeff92se

iTrader: (82)

You do know that na and boost applications are different right?

JClaw

iTrader: (17)

Yes, but I wanted a rough idea. I don't think no one will ever be able to make enough power NA to max out a 2.5", but what about boosted?

Jeff92se

iTrader: (82)

I think 2.5" should be fine for 3.5 liters of displacement. Boost. Some go to 3" with good gains. But when boosted, you don't have the same problems with exhaust gas velocities as you do with na. Hard to compare the two.

sleeper

with single exhaust like the maxima's probably around 350 to the wheels. duel exhaust would be more.

Stephen Max

iTrader: (59)

I put down 358 hp to the wheels with a 2.125" b-pipe and 2.36" axle-back.

IceY2K1

iTrader: (3)

Stephen,

You need to drop the cat for a run once you're back on the dyno. I'd bet it makes a big difference.

Stephen Max

iTrader: (59)

Yeah, I'm interested in what that would do. That would be incredibly loud, too.

chris'smax

iTrader: (3)

Hopefully with the VES i can get us a good dyno comparison in the next couple of weeks. Just waiting on the headers to be delivered on monday hopefully.

IceY2K1

iTrader: (3)

Stephen - Yes, loud however not REALLY loud until you go WOT. We had a 5th gen on the dyno with headers, stock cat, bpipe, and no rear section and it wasn't too loud until he opened it up. However, it was a closed room with the car facing out, so the sound had no where to go. Also, the sound definitely changed with a high flow cat. SC would probably make noise worse, but MAN did that sound mean. You need to go 2.5" back and get a turbo muffler or IMHO the best compromise between sound and flow is a flowmaster.

Chris - Yes, I'm still looking forward to how yours turns out.

DirtyErnie

here's the drill: boost increases your effective displacement (makes your engine act bigger than it is). http://www.flowmastermufflers.com/cg...ml?id=94nnFimb
that's a nice chart to find horsepower against displacement to get ideal exhaust pipe size. remember, atmospheric pressure is close to 15psi absolute. if you're boosting to 5psi, that's an additional 33% in pressure, which equals an additional third in engine displacement. making your 3.0liter (180cid) act like a 4.0 liter (240cid). 7.5psi adds 50% (3.0 is now 4.5) and so on. Exhaust size is still important on a supercharger/blower, you can have too much. On a turbo, the bigger the better, and no flowmasters on turbos: straight through only.

LatinMax

iTrader: (1)

I have read that the headers fpr our car produced less than 2 hp and was not worth it for the money and the 8+ hours to install.

chris'smax

iTrader: (3)

that may have been NA reviews but it has been shown by stephenmax that the headers on SC cars are far superior to the y pipe. I think he put down like an extra 30 whp w/ headers

IceY2K1

iTrader: (3)

Chris is right Gabriel....headers are SCers best new friend.

You dyno lately?

chris'smax

iTrader: (3)

if your talking to me, no. It seems like everything i order is on backorder. The VES is a 8 week wait since i had to send the one i got back because it was malfunctioning. Then i ordered my headers two weeks ago and have been since waiting for hotshot to deliver them to SWA. This week i am installing the Emanage, Support tool, 2.87 pulley, CAI mod, UR SC drive pulley, walboro, and the 510cc injectors. That ought to keep me busy until the other stuff finally comes in

IceY2K1

iTrader: (3)

No Chris, I was asking Gabriel. He has an auto(built) and PE510s and pretty much everything else possible, but headers, so I'd like to see what a 5th gen gains going from a ypipe to headers.

You're going to have quite a beast there Chris...I wonder what is the 5th gen SC only dyno record.

LatinMax

iTrader: (1)

Again I may be wrong. But from what I remember the 5ht gen gain very little with headers (and SC) over what the 4th gen do.
The 5th gen OEM headers is very efficiant (can't spell today) compared to the 4th gen headers.

Oh, no I have not just yet. But in the next few weeks I hope. Been slammed with work.

IceY2K1

iTrader: (3)

I'm not sure what 5.0gen you're referring too, but HNDA ETR on his 2000 SC'd Max gained 22.7whp by switching from a Stillen ypipe to Cattman headers.

http://forums.maxima.org/showthread....highlight=dyno

SPiG

iTrader: (7)

I always thought the 5th gen and 4th gen exhaust manifolds were the same pretty much the same except the cali spec with the precat, and that was why the 3.5 had such better gains with headers.

JClaw

iTrader: (17)

The "displacement/boost" thing mentionned earlier just proves how much headers helps boosted cars. Cattman told me his headers work alot better on the VQ35 than the VQ30, simply because 5th gen (2000-2001) and 5.5 gens (2002-2003) have the exact same exhaust manifolds. Nissan didn't make them bigger for the bigger engine. Imagine if you're boosting 10+psi with over 5(corrected) liters of displacement...

packetattack

iTrader: (1)

Chris, where did you buy the 510cc injectors from and what did they cost, if you don't mind telling me. Thanks.

IceY2K1

iTrader: (3)

He got them off a eBay for an ABSURD price of $4xx.

Going rate new is $870...check www.gruppe-s.com.

BTW, these are top-feed 5th gen injectors NOT 4th gen injectors.

packetattack

iTrader: (1)

Thanks for the info. $4xx is definitely a steal. Can the 510cc injectors keep up with a 2.87 pulley and 255lph Walbro fuel pump? I see some people running 550ccs. Does that extra 40ccs really make a substantial difference in the IDC?

Mishap

Does a '99 run top feed injectors? If it's the same as other 4th Gen Maximas you need galley feed injectors. Either look for a Deatsch modified injectors or get some Nismo 550's. We got a set of 660's from them Deatsch...haven't run them yet but hopefully in the next day or two.

You should be fine w/ a S/C and 510's. Our 370's managed 300whp and from what I've seen most S/C's reach about 350whp peak.

vortechpower

iTrader: (1)

My factory injectors are doing ok with 10psi. I emtied out my cat the other night and wow. It is actually quiter and feels alot more responsive. I noticed that my boost gauge needle vibrates really fast when boosting. As it goes up it is vibrating. Never had this happen before. Im guessing it has something to do with my exhaust since I just changed something and fixed 2 leaks, one on each side of the cat.