Drag and Drive Baja

[madmike]

Jealous here, I have not felt boost since last September have fun

[Chip Birks]

Jealous here, I have not felt boost since last September have fun

I think my last time was september or August of 2019

[Schweg]

Kenric it is a 12cm housing.

Chip and mike you guys need to find either boosted winter toys. Or get a simple project on the road. While I understand the fun of learning and building there is definitely a joy in just using it as well.

[buguy]

What is this "using" you speak of?!

[Schweg]

It’s where you don’t say dyno and you drive your toys.

[madmike]

Haha ,, I think I'll wait a couple more months

[Schweg]

Yeah thats brisk looking!

[buguy]

Damn that. 80+ degrees here already.

[Chip Birks]

Kenric it is a 12cm housing.

Chip and mike you guys need to find either boosted winter toys. Or get a simple project on the road. While I understand the fun of learning and building there is definitely a joy in just using it as well.

Wouldn't that be nice! Not gonna happen here for a bit, I'll just keep saving my pennies and adding to my future project shelves. Someday the parts will all be made into a car or two.

[Schweg]

So the 9b is under whelming in some cases.

It will produce boost under load in forth at 1300 and build as RPM goes.

I think that the open loop boost control strategy I’m using needs to be changed to a closed loop set up. But that is gonna take some reading and understanding.

It’s a descent turbo but the 13t most certainly is the way to go on a 1600 set up only using one.

I’ll get some log shots in a bit need some cleaner pulls.

Compound is still a go but the oil line place that was supposed to be open wasn’t I guess cause of Covid.

Maybe next week I’ll get them made up.

[buguy]

Where does it build boost in second gear?

[Clonebug]

The two different IHI turbos I ran for a few years were just about an 1/8 to 1/4 inch smaller in diameter on the compressor inlet than the 13T. The smaller one would hold a max boost of about 17 lbs at peak ..then drop boost as the engine revved. It couldn't maintain the pressure. The larger one died before I progressed past 13 lbs. It was great for around town driving......but not so much on long grades at 65-70 mph. It would now be ok since I have the switches to shut off the W/I and the Boost controller......at the time I didn't have that though.
They were great turbos for all around street driving but if you want more..there is a limit. These turbos were from 1986 and 1987 and made for an 1800 cc engine. The 87 turbo was slightly bigger than the 86 turbo.
The -9B is basically made for half a 3.0 liter so it should support a 1500 cc engine. It should have great low and mid range but might peter out at higher revs. Although the Mitsu engine it came off of will rev to 6000 plus I would guess. I would guess they never ran over 17 lbs stock though. The car manufacturers aren't going to put more turbo on than they will use......penny pinching at it's finest.
Size wise the -9B is quite a bit smaller than the 13T......If I was bored and ambitious...I might try it.......but I'm not......I'm happy enough with the 13T...It's just about perfect.
If I revved to 7000 rpm I would probably max it out.....but not at 5000 rpm.

Turbos seem to me to be like cams.....each has a specific optimum operating range.....where do you want that range to be since it won't work through the whole operating area.

Smokey Yunick wrote in his book about cams.....since he spent a lot of his life testing them......... He said a cam is optimal for a specific 300 rpm range. If you can find his 3 book series it's worth the money.......edit........wow the price has gone up a bit....... I got mine new at a swap meet......one of my better buys.
Where do you want that 300 rpm range.....is the question. He tried to figure that out on each and every track they raced on.

It would be the same with a turbo.....where do you want the best performance at.... in your rpm range.......each one is a trade off.

[Schweg]

So I ran some more logs to see what the car was up to, I am also fighting some surging at the upper end of my rev limit and I am unsure what was causing it.
So this morning I pulled the plugs and re gapped them to .018.

Here is the opening portion of the rev range



I know that my TPS is showing 80% I have to look at my pedal it gets sticky and I forget to really lean on it to get the response I want.

Clone I am sure that the turbo and cam analogy is spot on. But this also shows how good the 13t really is in supporting a very wide range on our engines.

I will still push this compound set up and I am interested to see the results. Though in my heart of hearts I think the ride in my buddies Porsche may have made me want torque and a stroker engine more then I want to admit. Time will tell.


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[buguy]

Interesting. I would have thought that 9b would have shot straight up to silly boost.

[Schweg]

Interesting. I would have thought that 9b would have shot straight up to silly boost.

I thought so as well. But I’m thinking it may also be my boost control strategy vs the turbo.