Diesel Power and Performance at 1000-4000 RPM

[Jmac]

Hi,

I've been reading a lot about extractors and exhaust systems for Toyota Hilux's and most say that there are no improvements and go turbo etc etc. For those of us with limited cash, can anyone suggest the best set up for maximum improvement for a Hilux diesel at 1000-4000 RPM?

Should I go for a 2" or 2.5"; muffler options?? Extractors - are there options for these? Lastly, price - I was quoted $1000 but this seems a bit rich to me.

Thanks for any advice!

J

[millers1]

Hi there Jmac, I have the 2.8D which I presume is what your talking about, I have extractors and 2 1/2 inch exhaust, Is there a big differance ??? I dont think so, maybe a tad more pulling power up hills but to me virtually stuff all, my mate has the 2.8 4 runner and he has standard manifold my other mate has a 5L 3 litre and by the time we get to the top of some hills I might be in front by a cars length, stuff all in it, I would rather keep the $1000 in your pocket and save an get a turbo, which will still require 2 1/2 inch exhaust to go with the turbo, Im getting turbo fitted to myn in about 3 weeks, wont be no speed machine but hopefully will pull up hills a bit better especially as we have a camper trailer behind us. Wont go any faster as it will still be reving at 3k at 110klm but at least hopefully wont die in the arse with head winds and the slightest hill crest. Regards Steve M

[Jmac]

Hmm, something to think about but the bloke at the exhaust centre said about a 20% improvment in performance at this range...

Yeah I was talking about the 2.8D

[ferrit]

Extractors, 2" and free flow muffler on my 2.8D with 300k kms.

All it really did was allow it to rev past 3200 rpm- will actually rev happily to 3500, then wheeze to 4000, but its not worth it by then, and changed the torque curve slightly and put a bit more torque up higher, so it does pull a LITTLE bit better at 100kph.

[tweak'e]

your never going to get much performance gain until you poor more fuel in. the exhaust helps the airflow and cuts out some loses but until you match the new air flow with more fuel you won't get much performance increase.

funny how no-one's mentioned any economy gains which should be reasonable.

[ferrit]

thats because there ARE no economy gains! 11L/100 at the start, 11L/100 after the exhaust.

Lot more noise tho!

[tweak'e]

mmmm.....with the drop in back pressure there should be economy gains. if you got more power without adding more fuel in then it should be more econmical. however it could well be a case of the more power you have the more you use it which negates any economy gains.

[ferrit]

you got it right there- its a 2.8L 4 pot Naturally athsmatic diesel... ever watt of power you can liberate you use, because you never had enough to start with!

i would say that the power gains i made from the extractors and exhaust are probably more than slightly negated by the 300,000kms of wear in the engine, and the sorry state of my fuel pump- its gummed up or out of calibration or just plain frucked or somethng

[Jmac]

Thanks guys, Ferrit just on you saying that there is a lot more noise, what is the exhaust note like? I'm probably going get the gear added soon but I don't want to sound like I drive a four cylinder Toyota Corolla

[whiteknight]

I had extractors and 2.5" exhaust on my 2.8D and it made it sound nice but really didnt do much to either power or economy, might have held a gear longer up a hill..

for the $1000 you were quoted I would look out for a 2nd hand turbo and throw that on with a straight through exhaust (no muffler as its not that loud) you wont regret it..

[Mick_n_Sal]

Mybe I was lucky, maybe it's a placebo effect, but I did Extractors ( manifold was cracked ), System ( tore the hell outta it on rocks ) with free flow truck muffler, Injector pump & injectors ( damn bp low-sulpher deisel ) and noticed slightly worse economy ( now 11L / 100 km from 9.5-10 ) but noticeable difference in power. Some hills I used to go back to second gear, I now climb in 4th. 3L Engine has 465000+ kms

Mick _n_Sal

[ferrit]

Thanks guys, Ferrit just on you saying that there is a lot more noise, what is the exhaust note like? I'm probably going get the gear added soon but I don't want to sound like I drive a four cylinder Toyota Corolla

best way i can describe it? Well at 2000rpm, it sounds somewhat like a truck on exhust brakes, its not blatty, but its definately throatier...

and at idle you can hear each cylinder fire at the exhaust tip!

[millers1]

I had extractors and 2.5" exhaust on my 2.8D and it made it sound nice but really didnt do much to either power or economy, might have held a gear longer up a hill..

for the $1000 you were quoted I would look out for a 2nd hand turbo and throw that on with a straight through exhaust (no muffler as its not that loud) you wont regret it..

Hi there whitenight, do you have a turbo on yours at all, if so was wondering how it goes, still trying to make up my mind on wether to do it or not, turbo shop said they run 8 pound boost, which is a safe level as to not blow up the motor. Myn has 285k on it Regards Steve M