Re: More Rtech dyno results
 

Hey Tom,
Could you email me the program/log so I can compare notes.
Didn't catch the injector size. We are running 72s with an Aeromotive with a 1:1 regulator (43-52psi) with no fuel shortage at 5800- 6000rpm on almost the identical setup except for the Valako Canfields.
We also run a large Holley high volume/low pressure primer pump into a large Racor separator as well which helps tremendously. It allows the rotary vane to do what it's suppose to; push and not pull :D
Do you have large enough feeds?
Thanks,
Dave

Re: More Rtech dyno results
 

Alpha! :p

Re: More Rtech dyno results
 

You can find charts on the internet published by aeromotive showing the stepped up voltage vs flow. I'm using a aeromotive eliminator fuel pump,if I remember correctly its rated for 800 lbs per hour at 13.5volts and 1100 plus lbs per hr at 16 volts. I'm feeding 63 lb injectors on my 540 with m-3sc procharger and it made over 950 ftlbs tq on dyno. We were trying to run a essex fuel pump on the dyno and it wouldn't keep up at all,ended up cobbling a barry grant 500 as a booster pump to get my pulls in on dyno and going to the higher flowing aeromotive and voltage booster when actually in the boat,Smitty

Re: More Rtech dyno results
 

Why would you not run a real fuel pump like a Weldon 2015 or a 2025?.
I am very familier with the Aeromotive pump, bosch, Holley, and Barry Grant. And the ONLY pump that will flow what they advertise is weldon.

RT

Re: More Rtech dyno results
 

In my case the amount of excess flow when not in boost would overcome my return lines and boost referencing regulator. My regulator boost references at 5-1,not 1-1 and I have not found a bigger one that will do that. If I went to big enough injectors that I wouldn't need to raise fuel pressure so much under boost I would also have to get a new computer and harness to trigger it so the 250$ the kenne bell voltage booster cost was a tenth of what the alternative cost plus the cost of re-dynoing it to get computer map correct, re-plumbing it,rxr'ing motor etc,Smitty

Re: More Rtech dyno results
 

I think the injectors were 72 but I don't know the pulley sizes. Apparently the reason for losing fuel pressure was an 11 volt battery. I haven't got a copy of the log yet, but we can compare notes when I do. The owner is a former Factory 1 driver/throttleman and can handle the boat, but I don't know how long the XR is going to handle the torque.

Smitty: It would be interesting to compare the curves; I will see if I can find your numbers and plot them on the same graph. Your intake, heads and cam should make more torque.

Re: More Rtech dyno results
 

I looked at the numbers last night but can't figure out how to plot them against yours on any program I have. I'll e-mail you a dyno sheet if you want to do it. I know mine made 45-100ft lbs more tq thru most of the curve,I'd love to know what made them different,probably the afr heads,Smitty

Re: More Rtech dyno results
 

I found the dyno sheet on your thread; this graph shows the comparison. The combination of the AFR heads, long runner intake and milder cam definitely make more torque down low, as much as 90 ft-lbs @ 3800; they two engines have the same torque @ 5400, after that the solid roller will pull away.

Kind of makes you go hmmm.... Both engines will be Bravo busters; but would the solid roller engine's ability to rev, combined with a lower pitch prop give up anything in acceleration? Would it be any easier on drives?

The blower pulley was 4.75" but I think the old M-3 gear ratio is 4.44:1. At 6000 RPM this is a blower speed of ~42,000 RPM. In your thread you said a 3.85" pulley was used and I think the gear ratio in the M-3SC is 4.1:1. At 5600 RPM this is a blower speed of ~45,000 RPM.

Re: More Rtech dyno results
 

Steve/Tom,
Great information!
If I can offer a suggestion...try an overlay of the TQ/BSFC curves, there may be some answers there.
Bob