Spent the day on the dyno. The 10 lb pulleys would only produce 6 lbs. The 14 lb pulleys would only produce 7 lbs.

I assume the belt is slipping badly. Anyone have experience with this set up?

I have not called Dustin as of yet. Just got home and need to unload the engine.

Will attempt to post a pic.

Here is the video. Dyno Pull

check the pop off valves to be sure they are closing all the way ,,run the vac. hose from the pop off to a vac.port that also gets boost it will slam it shut , push up on valve and hold finger over hose the valve should stay up if not its poped
this valve will let boost stay about half

what size motor and cam and dia.pulleys do you have
PM me I'll try and help I've dyno'ed a few of these there great !!

Curious of the same questions, cam, heads & etc.

I will measure the pulleys and test the valves here shortly.

4" and 3.5" pulleys.

It did make 970 HP @ 6,300 with 7 lbs of boost on 93 octane unleaded.

It has Dart pro 1 345's, top secret cam grind. 640 ish - 250 something 260 soemthing. Hyd roller 540 CID Dart callies oliver J&E 2 Pro systems Dominators.

Here is a video link Dyno Pull Changed it to mpeg1. the screen size is strange. Bear in mind we are in Oklahoma LOL. Ran wet exhaust flame arrestor etc. Made a hell of a mess.

Boost gauge on the back of the engine. Had to look at it manually. one water hose to the engine and one to the intercooler - oil cooler. Water hose dumps out back from the oil cooler and headers.

Wanted to simulate as close as possible it being in the boat.

did not want to tune it to the dyno headers.

Pulleys are just an estimation, not an exact level since heads, cam, carbs, ci, etc. vary boost. Looks like the belts are slipping, you might want to loosen the belt by letting the right idler move out just a bit and let the tensioner work close to it's range, it looks straghit up and down now (max) where it should be closer to 4-5 o'clock. The only other thing is the bypass valves, makes sure there working properly, if the carbs have a lot of vacuum, they'll hang the valves slightly open which could drop boost 1-2lbs, but not 7lbs. 970 with 7lbs is great, wait until we get it to 10lbs or 14. When you go to a pulley change such as you did and only 1lb, somethings wrong, every 1/4" should be near 2lbs of boost minimum.

Thanks,
Dustin

Thanks Dustin

Started out as you described and ended up as pictured trying to get more tension and wrap on the tight side..

looks like we're on target ,I've had several loose almost half boost with the valves leaking , check the valve but its most likly the pulley size ,you will love the quad rotor

I am some what computer illiterate so I thought it was just me when I couldn't play video. It works now.

Thanks Bobby and Dustin. The valves test good. I repositioned the hoses to under the compressors. And yes those carbs make a ton of vacuum. What awesome carbs. Used them as sent from Pro Systems. .64 BSFC

Only had one shot at the dyno. Will have it running in the boat this weekend. Will check it with the boat's boost gauge. If it is the same will see if Dustin will trade one set of pulleys for some smaller ones. Dyno time only on them.

The cam does have quite a bit of overlap for a 114 LSA grind.

TMP is building a pair of those now, you may want to call them....
985-649-9888