Best Dump/front Pipes For A 26 ?

[Nee-san]

I've got a set of Xforce on my GTR currently making 330rwkw and hope to be pusing 400-450kw through soon.

I wouldn't spend money on dumps given what i've got unless you could see a serious improvement.

Cheers,

Mitch.

[doo doo]

cheers mate ! looks like a nice piece of kit, any insight on weather an aftermarket ex mani is worth it ? again purely for MAX RESPONSE, i know the stock item is said to be adequate for fairly high power levels, but im chasing every bit of response i can

cf drive shaft

lightened flywheel

aluminium pulleys

anything i can think of to get nice early spool so even if mani/dumps dont get more KW its not an issue

Sorry skipped most of the drivel so hopefully not repeating anything already said. i got the best RESPONSE improvement with CES dumps and front pipe (substitute any similar product) PLUS port matching the turbo to manifold flange. I estimate about a 500rpm better response with these mods- power probably still the same I think in a GTR response is valuable

Currently have 540hp atw at 17psi (700cc injectors maxing out) with custom turbos hitting 12psi from about 2800 and max boost in before 4000rpm. Still kicks the rear out when coming onto max boost in second gear.

Edited April 16, 2010 by doo doo

[STATUS]

Sorry skipped most of the drivel so hopefully not repeating anything already said. i got the best RESPONSE improvement with CES dumps and front pipe (substitute any similar product) PLUS port matching the turbo to manifold flange. I estimate about a 500rpm better response with these mods- power probably still the same I think in a GTR response is valuable

Currently have 540hp atw at 17psi (700cc injectors maxing out) with custom turbos hitting 12psi from about 2800 and max boost in before 4000rpm. Still kicks the rear out when coming onto max boost in second gear.

id like to see proof of that, ive never seen a gtr make that boost without an artificial ramp rate especially @ 540hpatw

[thrtytwo]

Sorry skipped most of the drivel so hopefully not repeating anything already said. i got the best RESPONSE improvement with CES dumps and front pipe (substitute any similar product) PLUS port matching the turbo to manifold flange. I estimate about a 500rpm better response with these mods- power probably still the same I think in a GTR response is valuable

Currently have 540hp atw at 17psi (700cc injectors maxing out) with custom turbos hitting 12psi from about 2800 and max boost in before 4000rpm. Still kicks the rear out when coming onto max boost in second gear.

CES sound pretty good overall, wat turbo/s you running ? 540hp at 17 psi and full bost at 4krpm is pretty nice haha

[R31Nismoid]

id like to see proof of that, ive never seen a gtr make that boost without an artificial ramp rate especially @ 540hpatw

+1

400rwkw, with 12psi @ 2800rpm...

[NSNPWR]

BTW - Don't abuse people. It's not nice. Passionate discussion is one thing... insults are another.

Yes, indeed they are, so please address it with your mate that couldnt make his point without refering to me as 'simple minded'...

[NSNPWR]

Looking at the standard dumps compared to aftermarket ones, there has to be some gain had from changing them over.

Amen.

[Tangles]

Im expecting an increase in HP and Nm at the rear wheel from my forthcoming upgrade over stock items:

tuned length twin manifolds, HKS split dump pumps, dual 2.5" into 3.5" front pipe to mate into my cat-back system

running fresh hiflowed steel wheel turbos, 550cc inj, z32 afm, gtr intake & walbro 305lph external fuel pumps, power-fc

eventually going to do a rebuild, and I expect the exhaust to flow over 500hp:

hks oil pump, n1 water pump, 87mm hks pistons, attkd rods, acl race bearings, arp studs, greddy cams & adjustable gears, hks cam springs

cometic 87 x1.2mm full gasket kit, greddy timing belt kit, 30-row oil cooler, 52mm dual core radiator, air intake kit

throw in the electronics, roll cage, wilwood brake setup & semislicks - she should be a decent track car !

[perzn_34]

Hey guys ... im in the same confusion, my r34 gtt is running a hks gt-rs turbo and reads about 12-13 psi boost on stock gauge. My exhust is a full kakimotor 3 or 3.5 inch but STOCK DUMP that is missing two bolts as well haha :S... is this ristricting my exhust flow, so not getting full potential of the exhust?

this is realy important for me becouse my mates selling his dump pipe of his fujitsubo full exhust i was going to buy it today in couple of hours, so if i could get a quick reply would appericiate it guys.

BTW is it hard to install? howmuch would it cost if mechanic does it??

[thrtytwo]

I dunno what these guys would say but im pretty sure the GTT or equivalent gtst parts arent up to the same standard as the GTR ones, my suggestion would be definately to upgrade it

[perzn_34]

tufff.... easyy installl..? can i do it myself?? ive never done much mechanical stufff

[doo doo]

id like to see proof of that, ive never seen a gtr make that boost without an artificial ramp rate especially @ 540hpatw

Sure if you're around Bris I'll take you for a spin sometime. I understand the ramp rate issue- the figures come from road testing not dyno. I don't have a dyno sheet unfortunately but that can be organised, I'll make sure the boost vs rpm is displayed. I paid a bit more attention to it today and found that (I have a small boost leak issue under the inlet manifold atm) in 3rd gear with time to load (ie.uphill) I have 9psi at 2800rpm and 13psi at 3100rpm. The real crossover power (17-18psi) occurs at about 3800rpm. In 2nd gear it ramps a bit later (naturally) but still have full boost by 4000rpm (if I get off the throttle before it hits 4000rpm i can check the peak boost on the boost controller) Very driveable out of corners...... It should also be noted that the cams, cam gears boost controller gain and tuning (Motec M600) are all working to bring the boost on early.

HOWEVER, the difference with the dumps was noticed changing from stock dumps and front pipe to CES dumps and front pipe, still with stock turbos plus a better flowing cat.

Edited April 17, 2010 by doo doo

[doo doo]

CES sound pretty good overall, wat turbo/s you running ? 540hp at 17 psi and full bost at 4krpm is pretty nice haha

they're friggin expensive esp with the ceramic coating (which is starting to chip off....)

Turbos are custom jobbies that i'm not told the specs for- they do run a factory comp cover machined for a larger wheel and a .64 exh. The only issue is they will surge slightly at low pressure ratio which is bad for an afm setup, I had 440hp atw with the power FC, which i have since changed over to motec for the current 540 atw. At the time I bought them they were 1300 each new but that was a very good deal, i'd estmate 1500 ea at the mo.

[thrtytwo]

Looks niiice man. One day I might just try and make some similar to that design. I'm a boilermaker

[Adriano]

Trent, the setup where you had the gains, what power was the car making? Can i summise that there are negligable gains up to 330rwkw or so, but once you start puting gtrs's and the like there are gains to be had.

[STATUS]

Sure if you're around Bris I'll take you for a spin sometime. I understand the ramp rate issue- the figures come from road testing not dyno. I don't have a dyno sheet unfortunately but that can be organised, I'll make sure the boost vs rpm is displayed. I paid a bit more attention to it today and found that (I have a small boost leak issue under the inlet manifold atm) in 3rd gear with time to load (ie.uphill) I have 9psi at 2800rpm and 13psi at 3100rpm. The real crossover power (17-18psi) occurs at about 3800rpm. In 2nd gear it ramps a bit later (naturally) but still have full boost by 4000rpm (if I get off the throttle before it hits 4000rpm i can check the peak boost on the boost controller) Very driveable out of corners...... It should also be noted that the cams, cam gears boost controller gain and tuning (Motec M600) are all working to bring the boost on early.

HOWEVER, the difference with the dumps was noticed changing from stock dumps and front pipe to CES dumps and front pipe, still with stock turbos plus a better flowing cat.

That sounds much better and is around the norm under modest ramping, makes much more sense.

The hill scenario you describe represents a far higher "ramp" and it is definitely possible to see the boost your referencing to under such conditions, i use a "control" ramp to compare like to like setups which is the same as a flat road rolling on in fourth from 1500rpm which is less than the hill type scenario but almost identical to the on road conditions. We simulate the hill type ramps during tuning also but they give unrealistic boost response times.

Please dont think im criticising your setup as it sounds awesome, hence my reference to "artificial ramp" in my first post, everyone checks the boost response different and is why it is only useful to use the same dyno and tuner for back to back testing, or a set routine or road to road test the changes..

[VSPEC-33]

When I went to -5's I had HKS dumps and Just Jap's JJR stainless front pipe installed. JJR pipe sizes are twin 60mm inlet, 76mm exit and best of all it was only 300 bucks. Works perfectly on my car no boost issues always rock solid 19psi. There didnt seem to be any lag or flow issues as the car makes more power everywhere when comparing the stock turbos/dump/front pipe dyno run to the -5 setup with the bigger front exhaust and dumps installed. Car runs a decent speed (117mph) at the 1/4 mile that supports the dyno figures and suggests theres no lack of top end power (400hp at all fours).

In 4th gear the boost ramp rate is almost identical from the completely stock turbo, dump and front pipe, to the -5's, HKS dumps, JJR front pipe. So the way I see it, the -5's should be laggy by themselves, and if the front exhaust was inefficient, then itwould be laggier still. I guess the rest of the setup with cam gears, tune etc brings the reponse back close to standard GTR levels. So for some reason the HKS dumps seem to work on my car. Standard dumps may have worked the same, who knows, but while I had the turbos changed I wasnt going to wait to find out they were a restriction, and then have to change them later.