more supercharger talk

[truckinwagen]

possibly, but I have a 1.6 sitting in my garage, and yes, it is an N/A.

but with a little careful work the N/A can be boosted really hard, I know, I have done it already.

[LeonardoL]

truckinwagen,

Now I am curious, how much pressure are we talking about?

I have an IDI engine also (1.9 N/A), and was wondering how much pressure I could use in the intake without blowing up the engine...

[truckinwagen]

the main difference between the turbo and N/A motors is the piston cooling jets(later N/A's had the cooling jets and are therefore identical to the turbo motors) so the name of the game is to keep the temps inside the motor under control.

its not so much about pressure as it is about EGT(exhaust gas temperature).

as long as you keep EGT's below 1000*F or so for any prolonged period of time( my motor saw 1300* for a second or two quite often) your motor should be fine.

I was running as much as 25PSI of boost on a stock N/A with a stock headgasket and headbolts.
a metal HG(like the AAZ one) and head studs will allow you to run more without fear of HG failure.

I will say here that this motor ran for a year driven hard every day like this, it died in an accident(and because of rust) and the motor is still in use(since rebuilt, but mostly because it was easy to  rebuild once out of the car)

-Owen

[truckinwagen]

well, I looked at the stock G60 mounting bracket and I think if I relocate the alternator to where the AC compressor is supposed to go it will all clear the injection pump.

so I found and bought a G60 mounting bracket, so I don't have to spend a bunch of time fabbing one up.

I also pulled the motor I have apart to see what kind of shape it is in and the bearings look perfect, they plastigage at spec, so I will leave them in. the IM bearings look brand new too!

the rings need to be replaced however.

the head on this thing is beautiful too, barley any cracks between the valves, valves look new, and you can still see the line on the valve and seat from lapping!

I think all I will do is re ring this thing, clean up the ports in the head a little and throw it back together.

-Owen

[Pat Dolan]

Sorry to come late to the party, but I really have to ask why you would want to throttle (bypass) the SC?

I read your earlier comments about "freewheeling" under turbo boost, but, that really doesn't matter.  If the turbo starts putting out more pressue and runs into the positive displacement blower, who cares?  You wouldn't be making the turbo boost without throwing enough fuel into the engine to load up the exhaust, so at that time you "need" as much air as you can fuel up.  The only time that the SC would be an impediment is running low power at high RPM for an extended cruising time.  The solution is simply a higher gear (as MAP = RPM for the SC) shifting the air moving tasks more towards the SC and away from the turbo.  The same situation should apply while you are running just the SC.  If you want/need more cruise efficiency, just use lower crank RPM.  The EGT gauge will tell you what you can do.

The other consideration is that with the G60, you have a number of pulleys available to play games with the balance of boost from either the blower or the turbo.  Damn, I wish I was further West, this would be one fun project to play in.

[truckinwagen]

for the moment, the motor will be supercharger only.
and I am putting a throttle controlled bypass in so that at idle and cruise the motor is not asked to generate boost, increasing efficiency.

[truckinwagen]

well, all my engine parts came in today(sans headgasket), and I have a date with the engine stand tomorrow, so I should have a fresh bottom end(W/pics) tomorrow night!

I went looking for a cylinder hone and the only place I can find a ball hone(Napa) wants $120 for it!!!
sounds a little ridiculous. apparently there is no tool rental place here that has one either, so I guess I will have to go buy a stone type hone and be careful.

anyway, progress is on the way(as are a supercharger mount and TT race downpipe!)

I will post pics tomorrow

-Owen

[truckinwagen]

the TT race downpipe came in today, and I have to say I am not that impressed.
the thing has been used hard, beaten on, and damaged.

but I only spent $100 on it and it is indeed the stainless race downpipe from TT.


the flex sections have started to crack away from the welds, and someone has tried to re-weld them with a stick welder and an unsteady hand, blowing through the flex and making it worse.


it has 2" primaries and a 2.25" outlet that someone has beaten on with a hammer and attacked with a sawzall



the flex sections are a real bottleneck right from the factory, they only measure 1.5" ID, while the rest of the downpipe is 2" ID



I don't want to install an exhaust that is going to leak, so I plan on cutting out the flex sections and getting some braided flexes welded in.
I also plan on getting the worst of the outlet cut off and having a 2.5" piece installed in its place, as I wnt to run a 2.5" exhaust at some point.

I think I can have all of that done and still come in under the $350 TT wants ending with a better product.

-Owen

[Rabbit on Roids]

i wonder what the point of hacking a hole in the collector was? more power? or to mimic the sound of a fart can equipped civic?

[truckinwagen]

no, I think it was welded to the exhaust he had on his car, and he started to cut it off there and thought better of it in favor of a little farther away.

still a good piece to work with.

it looks like I can get 2" ID flex couplers that are 4" long from JCWhitney for $20 a piece, and I can probably get them welded in for $45(the local shops minimum cost) if I do the cutting and prep so all they have to do is the actual welding.

[gldgti]

no, I think it was welded to the exhaust he had on his car, and he started to cut it off there and thought better of it in favor of a little farther away.

still a good piece to work with.

it looks like I can get 2" ID flex couplers that are 4" long from JCWhitney for $20 a piece, and I can probably get them welded in for $45(the local shops minimum cost) if I do the cutting and prep so all they have to do is the actual welding.

you might have a little trouble fitting the two flexes in there side by side - if you use a 2" flex, it will stick out a fair way on each side - they mght not actually get close enough together to fit - but good luck. seems to me TT did a bad job designing that to have those flexes there anyway, the factory uro gti downpipes are solid. i have a set on my gasser car and i put a nice big flex after the collector, and since there is an exhaust hanger just near the shifter box it takes the weight of the downpipe anyway.

either way, best of luck :-)

[truckinwagen]

I have been thinking about just making it solid to save a few bucks anyway.

as for there being enough room, the outside of the flexes are 2.5" in diameter, so I think a 2" braided flex would fit nicely in place of the stock 1.5" ones.

I intend to put a flex at the end of it anyway, so I might just have it made solid.

[Rabbit on Roids]

I have been thinking about just making it solid to save a few bucks anyway.

as for there being enough room, the outside of the flexes are 2.5" in diameter, so I think a 2" braided flex would fit nicely in place of the stock 1.5" ones.

I intend to put a flex at the end of it anyway, so I might just have it made solid.

you will regret it making it solid. its gonna break in a matter of weeks, if not days. these engines torque too much to have solid mounted exhaust.

even tho there is two 1.5 inch primaries at the flex couplers, that makes the equivalent of a 3" single pipe. and if you are going to be running 2.5 inch pipe, that will be the biggest bottle neck, not the flex joints. how big are the holes in the flange of the manifold? not much bigger than 1.5" i bet... ive messed around with dual outlet 8v manifolds and they are not that big inside.

[truckinwagen]

the motor mounts will be all but solid when the diesel goes in(hockey pucks) so I am not too worried about it breaking, I might put a support from the back of the block to the downpipe too.

as for the flow, the two 1.5 pipes do not equal a 3" at all, the 2.5" will flow much better than the two 1.5" flexes.

[rabbitman]

it looks like I can get 2" ID flex couplers that are 4" long from JCWhitney for $20 a piece, and I can probably get them welded in for $45(the local shops minimum cost) if I do the cutting and prep so all they have to do is the actual welding.

That's a ripoff, I went to the local exhaust fabber and bought a 2.25" ID 8" long braided flex coupler for 25 bucks, no shipping and that's usually the killer. Look around and see if a local shop has one .

Here's my piece welded in to the DP,


If you have a wirefeed welder it's not very hard to weld this stuff......$45 is quite a bit

Keep it up, I'll be watching