Opinions on this dyno tune...final tune dyno sheet included
Please give your opinions on this "final tune". PowerVision and Target Tune was used. It's a TMan 124" Pro Series Kit w/ M8-226 2PS cam. Other components: SE 64mm w/ polished intake, SE 5.5 injectors, HPI 2-1-2 x-pipe full exhaust system
I know the printouts are not the tell all....but still would like opinions please, especially if you are a professional tuner. I'm asking because even though I'm no expert, the dips in the power curve don't look right.
What are you running for mufflers? You say the exhaust system is HPI, are the mufflers also theirs? Just taking a guess I would say you need a little more back pressure.
What are you running for mufflers? You say the exhaust system is HPI, are the mufflers also theirs? Just taking a guess I would say you need a little more back pressure.
Yes, HPI's mufflers (full exhaust), pic attached. I thought it might be an exhaust issue, but the huge dip (more like a valley) threw me off a bit. The bike doesn't run well at all to me...those dips are felt pretty hard during normal riding. I will be taking it to a more reputable tuner and changing the exhaust to a 2-1 that I already had for the bike. That will help answer the exhaust issue.
Yes, HPI's mufflers (full exhaust), pic attached. I thought it might be an exhaust issue, but the huge dip (more like a valley) threw me off a bit. The bike doesn't run well at all to me...those dips are felt pretty hard during normal riding. I will be taking it to a more reputable tuner and changing the exhaust to a 2-1 that I already had for the bike. That will help answer the exhaust issue.
Thanks for the help! Just trying to learn.
If you think it might be the fault of person that tuned the bike, then take it to your reputable tuner and ask their opinion. It might be something else, but the dips you are experiencing look like what are usually caused by exhaust, basically exhaust with little back pressure. I would have thought that HPI would know that and design their exhaust so as not to have a problem. I think they do tuning at their facility.
If you think it might be the fault of person that tuned the bike, then take it to your reputable tuner and ask their opinion. It might be something else, but the dips you are experiencing look like what are usually caused by exhaust, basically exhaust with little back pressure. I would have thought that HPI would know that and design their exhaust so as not to have a problem. I think they do tuning at their facility.
I do not know if it's the fault of the tuner or not. It's why I'm asking here...also to gain knowledge myself. I definitely will discuss with the next tuner and show him the print out. Reason I'm not sure if it's the tuner's abilities or the exhaust is he claims bike is running great...but not when I rode it. And to add..I immediately found an exhaust leak when I got bike home (long story)...back plate breather bolt was not tight and had 1/8" gap between throttle body and back plate. You could hear the whirling/whistling noise while standing next to bike while idling, and especially when I would blip the throttle quickly. Fixing the intake leak can throw off the tune??? I don't know.
I am familiar with dips and exhaust (back pressure). My Street Glide had CFR's and had a small dip at the beginning of the curve, but nothing like this.
About HPI...what can I say? They are the experts, not me..you live and learn. The exhaust probably works well on a stock bike.
I do not know if it's the fault of the tuner or not. It's why I'm asking here...also to gain knowledge myself. I definitely will discuss with the next tuner and show him the print out. Reason I'm not sure if it's the tuner's abilities or the exhaust is he claims bike is running great...but not when I rode it. And to add..I immediately found an exhaust leak when I got bike home (long story)...back plate breather bolt was not tight and had 1/8" gap between throttle body and back plate. You could hear the whirling/whistling noise while standing next to bike while idling, and especially when I would blip the throttle quickly. Fixing the intake leak can throw off the tune??? I don't know.
I am familiar with dips and exhaust (back pressure). My Street Glide had CFR's and had a small dip at the beginning of the curve, but nothing like this.
About HPI...what can I say? They are the experts, not me..you live and learn. The exhaust probably works well on a stock bike.
can't say that's all the problem but that chit right thar needs to be right before any tuning gets done
It's an interesting exhaust design, but having a collector that then goes to separate mufflers is a little head scracher. Would think it would be better with a true 2:1. D&D Billet Cat is a proven performer. I have that pipe with the same cam you are running on a 120 with great results.
04-23-2019, 11:21 AM
Opinions on this dyno tune...final tune dyno sheet included
