Where do you live? I would suggest finding a Dyno to rent. Some places will rent out their dynos if not already booked that way they can make money and do something else. I have a friend that does that in Garner, NC.

 

They’re a few dynos around, just haven’t planned a trip. Probably won’t need it since I’m probably only 100hp away from what production bare block can handle. Not going for max effort, just looking for 750rwhp on pump. The 600 bucks I put towards a dyno can go towards the turbos or injectors.

I did order some stuff to measure backpressure. I’m using a MS3 ecu so it will be easy to record.

 

I understand dollars competing. Depending on where you are price may very. The Dyno I use is probably not the normal. The last time I heard price is $125 for the first hour and $100 an hour after that. I am normally there for around 3 hours.

 

I pay around $800 for an afternoon/day.

ks

 

Found my papers, your only around 225-250ft/sec on compressor inlet velocity. 500 is usually peak efficiency, 700ft/sec is max, usually. You have PLENTY of room to go on the compressors, in fact your closer to surge than you are choke, which is just as inefficient.
Are your turbos also breathing in engine bay heat? Or are they getting fresh air? Breathing in 180°+ heat before being compressed doesn't help. For only 650hp you should be in the 58mm-62/3/4mm size of compressors.

 

It is breathing in engine bay heat, so 150 plus. Compressors are ok then. It’s the turbine that on3 said is a restriction. Backpressure sensor showed up today so I’ll see if I can get some measurements.

 

I think you'll find they aren't all that restrictive. I'll agree newer stuff is more efficient (to some extent, I have seen times where older stuff is more efficient. Modern stuff has traded efficiency for performance, greater operating range, etc)

But I think your main issue is breathing hot air, and not enough water flow.

 

I’ll see if I can get the inlets to suck air from the fender-wells, gettin tight in there.

If BP checks good and I fix my water flow, then the best thing to do is bump up the boost from 18 to 20 something to pick up 100 rwhp? I’m trying to understand the trade off I made when I went with such a low compression (8.5:1). I did it to be able to run more boost/power on 93 pump gas.

Does a lower compression mean I can run more timing at a set boost level? Or does it mean that after a certain psi on pump with a higher compression, you have to pull so much additional timing that egts get too high. Where as I may be able to currently continue to pull .8deg/psi up to 25psi before I have to go over the .8?

#ad

 

I'm not a tuning expert, id expect someone like @B E N to answer this with more clarification.
But it's always been my understanding that reducing compression ratio decreases the temp rise during compression, resulting in less chance of pre-detonation. So more advanced timing at the same boost level.

 

You are going to pick up a bunch of power if you can get charge temps down, and you will be able to up the boost once they are in check. I would start there, you might get your 100hp just by optimizing the combo and adding a psi or two. And it should be safer on the engine with the colder charge.

Timing advance requirement is dictated primarily by charge density and chamber efficiency, all you are trying to do is light the mix at the right time to get peak combustion happening at the right point in the stroke. Once you have timing optimized for the combo and boost level there isn't more power to be found in timing. Eventually you get too much lead you stop seeing power pick up.

Typically lower compression ratio means a broader tuning window, but with your power goals and displacement I don't think you need to mess with it. I don't think you will need to run this engine on the ragged edge either. You should be able to be pretty conservative and give it a good long life.

As @Briansshop mentioned: more cam, more RPM. That will be the easiest/cheapest way to pick up power if you can't get where you want to be with the hardware you have now.

 

After doing quite a bit of looking around, I’m either going to get a second EBP-40 pump and run in series, or pull the heat exchangers drill and tap for 1” line, get larger AN line, and bigger pump. Currently the radiator is 1/2NPT and the exchanger is 3/4NPT.

Easiest route is get a second pump, which is what I’m leaning towards. Probably should check system pressure to see how much restriction is truly there first.

 

If I remember right, 3/4" hose will flow 20gpm before going turbulent.

 

First thing I would try is to direct outside air into the turbos and get some real filters on them. Even do air boxes like I did and get fenderwell air into them. Even if you have to mod the set up to turn the filters into the fender, it is the cheapest and first thing I would try.