DRZ - Forum

Moin,

I´m asking in english because my germanh is good for reading, not writing.
Member from die Niederlànde.

I want to have my dr/z400sm ´05 head ported.
It already has 94mm-434cc, fcr39, yosh trc, hotcams st1.
I want to put in Ferrea oversize valves.
Later maybe go 95,5mm bore or stroker and wilder cams, bigger carb.
I hear good reference for ABP racing.

My question is
-does anyone have experience with ABP porting
-does anyone have any CFM-flow figures on their portwork (or flow graphs)
-can they do 1mm oversize

Thanks!

had a 05 drz without big bore kit but with head porting and cams all setup by abp racing.

engine had great torque and "real" 50hp just with a tm36 carb...most potential on the drz motor= cyl head (ports and valve seat) !

get your motor there, no bull, no hassle put back in and have a fine running engine. people from all over europe send ther bikes there and get a dyno tuned bike back.

all that big bore and big carps are crap witout a cyl head that doesnt work on that

WOW!

That is a competely different story comared to what i read for years on Thumpertalk forum.
If you say you get 50 real hp from a 400 with BSR36 most would laugh at you.

But i like to hear this info! I don't just follow.

The stock dr-z head flows very well (136CFM@10" at 10mm open)
They say porting is only usefull if you go over 50 wheel HP.
Getting to 48 WHP is (their story) is done by: FCR39, Pipe, Cams, bigbore. I did that.
Gives 48 WHP indeed.
So porting is only needed for strokers (470cc) they say and even then the last step.

If ABP porting works that well im very curious to find out what it does for my engine.

Did ABP give a flowchart before/after with the porting?
Do you have dyno graphs of you bike?

Hey Jazz,

the DRZ from Sumobob has a TM36 CARB not the BSR36!

Aha TM36!

Hey sumobob,
Dyno numbers are very different across benches as we all know.
Best is if you have before-after numbers.
My dyno (superflow windyn) for example said 34Wheel HP stock and 48 after tuning +14.
(no sound killer in the pipe, very loud! on the street i ride with a killer in)

For example suzuki marketing said 40 crank hp for S/SM and 50 for E.
My dyno says 34 HP S/SM and 41 HP for E.

Do you know before-after numbers on your ported bike?

listen, why should head porting be a last step?
gas flow,compression,cams,overlap etc is what gives hp...without touching reliability of the motor, just improving oem.
more disaplacement first of all doesn´t affect nothing but reduces your reliability!!!!

talk to that guy and he will tell you another story. he tried big bore kits and works on that engines every day before those forum kids did.for them a street legal bike is if it lasts more than a 100km...

we had my bike on the the dyno,before and after. and that dyno worked well not like those corrected measurments.
that was 50 crank hp...not whp...but still.
http://www.supermoto-umbauten.de/141/Pr ... stand.html
we are talking about a stock like running engine that will last the same with nice torque and hp. we even tried a bigger carb on that setup, getting 1hp more at the top end while loosing torque in middle rpm.

with your setup you will even waste more potential withoud a ported head.

http://www.supermoto-umbauten.de/755/Zy ... lerie.html

i had stock 38,xxhp...than did tm36, k&n filter,akrakpovic exhaust and header, finish..44,xxhp.

then a year later decided to go 440cc...changed opinion and "just" did a head porting with "e" cams...anything else stayed....had 49,70hp...

i run the bike just on supermoto track later and if power were the only reason i would not have to complain and change to rmz

Hi Sumobob,

ok now it nakes sense.
my dyno gives about 4 hp less, it is the difference with wheel and crank hp.


You had a setup that is equivalent to an E model (with good pipe), with porting extra.
E (with good pipe) model gives 42 on my dyno, so 46 at yours.

So porting gave you 3HP
And that is consistent with 9CFM extra flow like ABP says the porting does for dr-z.

The 440 bigbore would have given 4hp i think, maybe less because 36mm is a bit small for it.
By the way 94mm/440 cc bigbores are as reliable as stock on the drz. Really.
I have mine for many years. No problems. Same in the USA, hundreds of problem free bigbores.
The only thing may be the head-gasket, but the torque for the head-nuts is wrong in the manual!
If you do correctly, no leaks.

Thanks sumo, i think i'm going to do the porting at ABP.
They seem to be real pro's.

my setup wasn´t 100% equal to the "e" model. the only thing that was equal was the cams, which were from abp but similar to those from the "e".

and yes that was probably around 46hp on the wheels and 50hp on the crank which is pretty enough on a 400ccm and actually the power the bike should deliever from the factory

and yes 440ccm may be reliable too. but the guys from abp tune those engines for a similar reason. they make em more "driveable" gaining torque and hp around lower and middle rpms wich actually gives a good response if u drive on public roads.

also u can not add hp from this part + hp from that part etc it is the whole setup together.finetuned on the dyno.

in my opinion the setup with "step2" from ab (header,akrapovic,head porting,cams,tm36,airbox mod) was the best solution between reliabilty and power, for the street!!!!!!
the bike ran so smooth...u thought it´s just stock.

if you go to 440ccm+racing cams+39carb you may get 55hp or little more....but on the road you dont need that.
no matter if you have 50hp or 55hp you areeven to slow anyway....u still have a 1cyl bike that does 150km/h and finish!

so 50hp with a good response and good lower torque is enough!

if you go with the bigger setup ok....but then don´t "save" the money on a head porting. if u do all that work and spending money anyway.
and dont forget the drz ain´t never gonna get a race bike....

Hi Bob,

it's been a while. Thanks for you response. It took me a while to understand your words about 150 km/h not beeing enough...
This is a german forum. In die Niederlände 130 is the limit. (very recently, was 120) Stock SM gets to 160, (174 indicated).
With 15/38 and 55 hp (up to 10k rpm) it should be about 180. Enough to loose my licence on the dutch highway, not enough for Germany

It will never be a racebike, but i like to work on the bike
It is lightended, better brakes, ohlins etc.
Silly i know, other bikes perfrom better for less and i will never get the investment back whan i sell the bike.
But i intend to keep it a while. I just like it.

Looking into getting a ported head with bigger intake valves now.
+15-ish CFM's. And able to run the even wilder cams i have laying around b/c better valves/springs with not reliability issues.

I will dyno before/after if time allows and post up here if you like.

Forgot to tell:

I am surprised the porting works so well.
I have 2 (3?) reasons for that:

1) the DRZ 400 (abp stg 1) is well above 100% volumetric efficiency at peak HP rpm. About 108%. That is a lot already.
2) The head flow is not the restricrive factor (bottleneck) for making more power, unported the head is able to go to 53 (my HP readings, about 58 yours).
3) not a real reason: Eddie Sisneros, well known dr-z tuner, says it "the final step" to port, because the head flows so well stock. Only usefull on +4mm bore +4mm stroke engines he says. And needs bigger valves otherwise it will not help he says. Your bike/abp proves otherwise.

Anyway. we will see.