N/a tailpipe turbo...

[sssubmarine]

....Alright , I 've saturated the forums of all the n/a fitted with boost. I've a situation and could use some specifics. I've an 87' to which I mated a IhI turbo off a 2004 cayenne (first turbo in the series of the twin setup) didn't take me long to do it(less than 2 weeks) and what a feeling to know your theories are correct when you see boost on the guage for the first time..

A few problems and questions I have on this car, the FQS switch had broken its solder joint and was hanging down, my attempts to remedy this problem has fixed the hanging aspect, but weather or not the connections are any good , I guess will be left to the engine gods. I've read of a Ford dme in the forums and was hoping someone could give me some specifics on this transplant, and also, I've read of "supercoupes" fuel injectors being a safe upgrade, that they pumped more but still retained the low impedance required for my stock dme...is this true? or are there better bigger injectors i could retrofit, the car is pushing 6-7 psi,,,lol with virtually no lag..yee haw.

Another question is I'm experiencing some violent hesitation mainly in 1st gear, which scares the hell out of me, especially not knowing if my dme is functioning properly...doesn't really make sense to me 2nd, and 3rd are good, BUT has some surging...and thoughts?? and the MAP sensor seems to be an issue, but I know nothing about this aspect, and or solutions for it, ,can anyone help??? oh, i have the FQS ON THE 7th position...

[v2rocket_aka944]

rear-mount turbo huh? i think this is the 1st ive heard of on a 944. cool!


what are you using to interface the MAP to the DME?

what gas do you use?

as for the injectors i have a set of the injectors in question. they are 36#/hr units and are low impedance like the 944 dme (951 injectors are high impedance), they are off a ford 2.3 turbocoupe though. in my reading the "supercoupe" injectors are all high impedance but there might be some low ones in there.

[alxdgr8]

Well you need some type of real engine management to begin with. 6-7psi is too much for a stock DME/injectors to handle. Do it correctly now and it will be cheaper than when you blow something up.

[krystar]

well....sorta congrats..but remote turbo setups are usually horrible. you're just losing too much heat with an extra 4ft of piping.

and should u ever hit a pothole or a speed bump...well there goes yer turbo.

and what about your turbo oil return lines? if the oil doesn't gravity return to the pan, it's just going to sit there on the turbo seal and get nasty and ruin the seal.

[sssubmarine]

vr2rocket...i am trying to find out about interfacing map with the dme ,i know nothing on the subject, the injectors you have are 36# low impedance, what are stock 87' n/a rated at?? i thought it was close to 25# but really have no idea.. am glad you told me the supercoupes were all high impedance , that just save me some cash and heartache,,thank you.
..i got the boost down to just under 5psi, on 93 octane pump gas, if i get tired of the 5psi, i plan on upping the boost but using a HOBBS boost pressure switch to inject propane (108 octane) thus hopefully eliminating my fuel AND detonation problem....

alex, yes i am worried about the limits of my stock injectors AND dme, i have no idea what the limits are,,,,but hopefully talking to you guys will help me do just that,which is NOT burn this one up..lol

krystar,,,,this thing is running awesome, except for getting rid of the gasses at high rpm''s, and your exactly right about the oil return, i did mount it's own oil canister for it, but the return hole is by no means mounted in the "down" position, so smoke everywhere after romping on it a couple runs,,,,call me stupid, but seeing that the turbo doesn't get very hot, I might try to grease it...i know it sounds bad but i've really nothing to loose right now,,, i'd like to get some pics up for you guys, but seem simply attaching photos is not an option on here,,am i wrong? oh, and i've also mounted a "in dash" fuel pressure guage, don't know if anybody has seen this yet, but works great!!!

another note,,,,I had originally thought i had blown seals on a seemingly new turbo..this from the prodigious amounts smoke,,...would not having the oil return hole in the down position AND having the reservoir mounted so HIGH up in the trunk produce this kind of "Valdez" phenomenon?

[v2rocket_aka944]

i think with some bigger injectors and an IC on 93 octane youll be ok up to around 10psi

im in the process of supercharging my NA and im looking at around 10psi intercooled on as close to 91 octane as i can on stock dme with some timing pulled

[alxdgr8]

You need a external pump to get the oil back to the engine.

[sssubmarine]

rocket, am pretty sure the 8 foot of pipe running from the back of the car to the front has ic'esque type properties,,would not know how to test this theory thou...now if i put the bigger injectors on, would i have to get a chip mapped for that?? particuarly the 36#ers you talked about....

alex, the external pump might work to pump it back the oil back up to the reservoir, but i still won't be able to position the turbo with the drain hole faceing down,,,,I wonder if drillling another drain hole in the "down " position would be feasible..

...another question that has been eating at me is,,,what are the reprocussions for retarding the timing via "one tooth" on the timing belt??? I know there are adjustable timing gears but I'm trying not get in the "should have just bought a 951" price range...thanks for your time and patience.

[krystar]

but the spark timing isn't set by the timing belt. the timing belt is the valve timing.

[sssubmarine]

...what good are the adjustable cam gears then?..I was hoping to retard the timing mechanically just to be on the safe side..guess I'm at the mercy of my delapitated dme....

oh, and has anyone tried "viceing" their fuel regulator to increase fuel pressure?? I guess it entails removing it, crushing it in a vice to increase pressure...sound nutty?

[speedracing944]

for retarding timing you could buy an offset key or you could loosen all the bolts/setscrews from the cam to the ignition rotor and while twisting them in the desired direction (retard) tighten the bolts and screws. You can change the timing a small amount this way.

Speedy

[rickharrison]

The remote turbo's long pipes do act as a "IC" since the turbo discharge cools along its path to the front.

STSturbo.com sells these in kit form...they would be a place to look at their kits for ideas.

Of course, you likely lose some boost in the long pipes...so you'd have to crank it up higher I'd think, with bigger 951 injectors, an adjustable FPR and look at a fuel management system (MAF conversion).

IIRC for each 10 degrees of cooling you add 10 HP...give or take, so an IC is a good idea.

[sssubmarine]

hmmm, maybe I'll look in to the ic thing more,,,it wouldn't be hard at all for me to splice an ic in the plumbing somewhere, i mean i've already figured out how to run it from the back of the car to the intake with ample clearace for slow opossums and coons and such....

am still trying to figure out how to dump more exhaust at high speeds, a boost activated 2"exaust valve would be ideal, but still trying to keep the cost down...

speedy, if the rotor was able to rotate on the shaft, wouldn't that allow me to adjust the timing?? if so maybe i can modify the rotor to to rotate and then lock accordingly...i relize the knock sensor should be able to compensate to prevent "knock" , but what i'm reading seems people are getting detonation regardless of knock sensor..

....oh and Rick thank you for the reassurance on the ic thingy,,,well check out that site to see if they have any good ideas

[krystar]

what size piping do u have on the exhaust of the turbo? even with low boost, a 3" is prob still good.

where is the turbo situated anyway? mid section? or more rear towards the axle?

[flash968]

in dash fuel pressure gauge?

please tell me this is an electric sender driven gauge, and that you are not running a fuel line into the cabin, which would be incredibly dangerous

if it is electric, i'd like to know more about it

[sssubmarine]

i lanced the muffler off at the weld, welded a 2" treaded galv. nipple in place, afixiated a 2"threaded galv. flange to the turbo(was not easy at all) this allowed to spin the turbo on to the pipe in a matter of seconds, it removes just as easy once the oil lines are moved,,,,the inlet of the turbo was 17/8" which I ported to meet the 2" pipe flange, the turbo exit is about 5-6" in diameter...and dumps into atmosphere,,,you can literally watch the internal wastegate work if you have someone work the throttle,,,

[sssubmarine]

flash9688,,,the guage is AWESOME,,,and has a sending unit at the end of the fuel rail, i have a shut off valve on it too, just incase, it is a oil pressure guage , and it reads perfectly and accurately...i 've done alot of reading, and to my knowlege, i'm the first one to do it...no more guessing if your starving for fuel at 130mph!!!!!!...oh, and thou the sending unit has connectors for 2 wires,,YOU ONLY NEED 1!!

[HondaDustR]

What's all this about adjusting ignition timing by shifting the distributor rotor position? The ignition timing is all done in the DME using the crank sensors. The ignition can be retarded a little with the FQS, or changed to whatever you want on a custom chip tuning, or a standalone programmable ignition like the megajolt. FQS - Fuel Quality Switch

Notice how the rotor contact is really wide compared to the distributor points. That's so that the DME can have a range of ignition advance/retard settings and the rotor contact will still be able to deliver a spark to the distributor without having to worry about mechanically advancing or retarding the rotor as well.

The adjustable cam gear will change the cam timing in relation to the crank, allowing you to tweak the power curve up or down to a certain extent, more for dialing in a camshaft to its peak performance timing. The 944S 16v cam gear is adjustable from the factory and there's a complicated procedure to get the timing set correctly. I've heard people have been able to get those motors running even better by tweaking the cam timing on a dyno, or more informally, driving, tweaking, driving again, etc. They "come alive" when the optimum timing is found.

[flash968]

sssub - really? that worked? hmm - i guess that makes sense - it doesn't know what kind of fluid is there - i may have to see if i can do that - my application would be a 968, so no end rail tap point, but i might be able to figure this out

honda - yes - power can be manipulated by altering relative cam position - the process is indeed tedious - on the 968 though, as an example, even though you follow the "normal" procedures, there is as much as a 20hp difference available, depending on where you put it - it is important to remember though that if you seek power up top with this, you will sacrifice it down low, and visa versa

[alxdgr8]

You should be able to "clock" the center section to any position you want in order to have the drain facing straight down. Should be lock-rings on the turbine and compressor housings that once you take off will allow you to spin the housings.