Isuzu I-Mark diesel

[truckinwagen]

I figured they would have to be inverted if they did not have a siphon tube...

anyway, I changed my jet to a .020 to start with.

have to see how it does when I get my bottle back.

-Owen

[truckinwagen]

got the bottle back, turns out the jet I had in was a .026(the smallest I have)
not sure yet, still need to do some tuning.

it stumbles with nitrous until about 2500RPM(will actually stall if too low) and I run into my high RPM timing stumble at 3500RPM...

it does pull a little harder on spray, but not as much as I would like to see.
gonna turn the fuel up and see if that helps things along.

gonna also install the soft advance spring and the clearanced timing spring cover to help with the high rpm timing issue.

wish I could get a smaller jet local(the smallest I can get is the .026) to help with a burnout as the converter stalls at 2000RPM, and if I spray it will just stumble.

-Owen

[81 vw pu]

I might to the same when I go to my new place, where I will have space for it.

do the big bottles have siphon tubes in them too?(so you get liquid and not gas pulled into the little bottle)

have to figure out a way to get big bottles without a pickup though...

still waiting on my bottle to be filled, the shop I dropped it off at didn't realize they only had 3LB in their big bottle, and are still waiting for a new one to be delivered.

-Owen

I have not had one with a siphon tube in it yet. I was told the bottles with siphon tubes have a white line down the side.
The ones I get have to be inverted to work, picked up a stand for cheap that screws on bottle threads.

i bet thats a handy lil stand.. and a great way of attaching it too..

Heres one like I use, found one for $20 tho.
http://cgi.ebay.com/ebaymotors/Nitrous-Express-15930-Bottle-Stand-JEGS-_W0QQcmdZViewItemQQhashZitem2eb473d7eaQQitemZ200595986410QQptZOtherQ5fVehicleQ5fParts

[truckinwagen]

well, turned up the fuel which helped alot.

pulls pretty hard now, and does not splutter if I hit the nitrous on the footbrake for a burnout.
but unfortunately it wont brake the tires loose as of yet.

it will eventually(more tuning to come)

I went ahead and installed the soft green advance spring and clearanced cover.
the isuzu spring seemed the same as the soft VW one, but the clearanced cover will certainly help.

I have not had a chance to take it through its paces since the changes though, so I will have to report back about performance.


pulling the isuzu pump really makes me miss my VW...

[81 vw pu]

Good to hear your making progress, had me worried with the sputtering but I've never had to deal with a automatic trans.
I think the automatic would be awesome for when you get your turbo on (spool up turbo when you power-brake). Did you see any change in egt's?

[truckinwagen]

not really, but it is hard to tell, when I floor it the trans shifts itself.

it does stop smoking on the juice, might increase the fuel to make sure I am taking complete advantage of it.

-Owen

[81 vw pu]

Yeah keep a little smoke, that way you know your not wasting nitrous.
 Also I read somewhere the other day about retarding the pump on a diesel just like a gasser when using nitrous.
I've never tried it on the caddy tho.

[truckinwagen]

well, my car was retarded(to the point of stumbling) past 3500RPM, and the nitrous did nothing for that, so I would disregard that.

in fact, I would think that advance would be your friend(to a point) just like it is whenever power is the goal.

hopefully my high RPM stumble will be fixed, and I can see what this thing will do on a hard pull all the way through the gears on nitrous!

I would really love to have a manual(or even a manual valve body to give me control of what gear its in) and may get there someday, but for now I will just have to tune it to work with an auto.

its sad, this car would be a real screamer with a manual trans(manual ones got 55+ MPG, mine is lucky to get 30) the auto just sucks so much power from it. 
now an overdrive auto with a lockup converter, yes please! all the fun of full throttle shifting and brake staging with none of the lost power or mileage(almost anyway) sign me up.

gonna try for a 200-4R sometime this summer.

-Owen

[81 vw pu]

I found where I read about retarding timing, guess its only when adding lots of nitrous.
http://www.nitrous.info/diesel-nitrous.htm

How does your trans get a signal to shift(tv cable or vacumn modulator). Could it be adjusted for higher shift points?
I unhooked the vacumn line on my drag cars turbo 350 and it won't shift till about 5500 rpm's unless I shift manually.

[truckinwagen]

its a TV cable(no vacuum on the diesel)
problem is, if I disconnect it and leave it loose, I can manually shift it but the line pressure will be low(idle) which will trash the trans in short order.

if I disconnect and pull the TV cable tight the line pressure will be up(like a vac actuator that is left unhooked) but without a manual valve body, the transmission will want to stay in the low gear until 5K regardless of shifter position.

no real way around it, if it was a GM tranmission(or a ford or chrysler for that matter) I could get a different valve body to act the way I want, but since its an Aisin-Warner, there is no aftermarket for it.

I guess it would be possible to pull the valve body and modify it, but thats alot of work and I'm not sure what would have to be done to it anyway.

if I get and install a 200-4R I get the overdrive, lockup converter, and I can buy a reverse pattern manual valve body for it, so all the TV cable does is control line pressure.

couple that with a ratchet shifter and it would be quite fun to drive!

-Owen

[maxfax]

Are there any adapters out there for that engine??  IF there was something out there to get you to a SBC bell housing, a T-5 might not be that far out of the picture... 

[truckinwagen]

nope, no adapters. but one could be made.

trouble is, I don't have access to any parts from a manual version of this car(pedal cluster, shifter parts, etc...) and fabricating those from scratch would be a large undertaking.

putting in an auto with a manual valve body would be much easier, and almost as good.

-Owen

[R.O.R-2.0]

its a TV cable(no vacuum on the diesel)
problem is, if I disconnect it and leave it loose, I can manually shift it but the line pressure will be low(idle) which will trash the trans in short order.

if I disconnect and pull the TV cable tight the line pressure will be up(like a vac actuator that is left unhooked) but without a manual valve body, the transmission will want to stay in the low gear until 5K regardless of shifter position.

no real way around it, if it was a GM tranmission(or a ford or chrysler for that matter) I could get a different valve body to act the way I want, but since its an Aisin-Warner, there is no aftermarket for it.

I guess it would be possible to pull the valve body and modify it, but thats alot of work and I'm not sure what would have to be done to it anyway.

if I get and install a 200-4R I get the overdrive, lockup converter, and I can buy a reverse pattern manual valve body for it, so all the TV cable does is control line pressure.

couple that with a ratchet shifter and it would be quite fun to drive!

-Owen

what model trans is it? my toyota  pickup had an aisin-warner (A-43 or something like that) 4 speed slusho-matic trans, lock up converter and overdrive.. that thing got BETTER mileage than a 5 speed truck. it was 2wd, but none the less, those trannies are awesome. the stock converter stalls somewhere around 2k rpms, i always thought they would be awesome with a diesel in front of them.

might be something worth looking into, i KNOW that those aisin-warner toyota 2wd trannies are tough, and fairly efficient.

these 1.8L engines are different bell pattern from the 2.2L engines arent they?

[maxfax]

Didn't think about pedals and whatnot..  T-5 would have you covered on the shifter, but woudl probably have some goofey ratios for a diesel...  Auto would probably be easier all the way around, once you got one that was tuneable..  Do you happen to know which model trans that is??  And as Kevin mentioned, it's not out of the question anymore to get better mileage with an auto.. 

[truckinwagen]

I think its an A-25 or something like that, but I can check tonight when I get home.

I would.really like to use a trans that I can put a manual valve body on, so I can choose manually what gear it is in regardless of conditions.