If I could ask for a couple of opinions. Like many, I am trying to weigh performance vs looks, at least according to how I see it. I have read a great deal from many generous posters about performance upgrades (HQ 95 or 98, GMR, etc) and can tell you that I have already saved a lot of money and headaches being forearmed with the advice from these contributors. I have also read a lot about exhaust, and as much as I would like to love the way a Fat Cat would look (I know I would like the performance) on my 2005 Deluxe with a big bore kit, I keep coming back to V&H true duals or pipes with that "Nostalgic" look. So the question is: if I were to go with say an HQ 95 kit with head work, but put on true duals instead of high performance 2 into 1 exhaust, how much torque/HP will I sacrifice and will I just be throwing my money away on the performance upgrade? Thanks for any and all opinions.

Ted

 

I havethe Bassani power curve true dualheaders with the megaphones. The Bassanis look nice and they will out perform the V&H true duals on any stage II or III set up. Depending on the set up, they will do almost as well as a 2 into 1 header. Check it out.
FYI: You will find the best price on the Bassanisin the united states at American Classic Motors. (610)-754-8500. ACM will not be undersold. Again, check it out.

 

https://www.hdforums.com/m_2783982/tm.htm

 

i still think i'm doing the coin toss on superbowl sunday.

 

I would stay away form the V&H Headpipes they are not stepped and I lost almost 10HP over my Rinehart True duals. Had to buy another set of Rineharts. The Tune was done by Doctor Dyno a very good tuner and I got the HP back as soon as I put RH back on and re tuned it.

 

Just curious, where did you lose the 10hp, was it over the entire curve or just peak? Was there the same change in torque as well?

 

That is a very important question, just because someone lost XX HP does not mean that the bike is not as quick, it may even be quicker without it because the shape of the HP curve has improved. Even ifsomeone claims they madeXX moreTQ, that does not tell us anything unless we knowat what RPM they are makingmore TQ. If someone claims thatthey made more peakTQ and more peakHP, this does not always mean that the bike is quicker eitherbecause if these improvements didnot occur in the RPM range that we use, it may be wasted money.

Having beenenvolved withautomotive chassis dyno tuning for acouple of decades, we have had many examples of this. The best way to predict ifengine mods have improved performance is to overlaya before and after HP curve over one another. The TQ curve is not necessary because always remember, at a given RPM, if TQ has increased, so has HP Plus, a HP curve also indicates where your shift points should be.Often we have seen peak HP decrease but the vehicle turn better times at the track or is and feelquicker (there often is a difference)on the street because the power curvewas moved and is now moreusable. So often I've heardit said that dynosarenot always good predictors of performanceon the street or track. This is usually because a customer shows up at the dyno shopwanting more HP, or TQ or both and gets it, then finds out that it did not help or even hurt because of what we are stating here. We as tuners often made vehicles quicker without the input from the customer because theywere often too rapped up in peak numbers.

Example, I am in the process of changingto a different cam grind on my bike because the peak HP occurs atmy redline, 6600 RPM, not good. I want it to peak at around 6000 RPM so when I shift at 6600 RPM I will average more HP, even at the expensegetting less peak HP. I've seen many engines peak their HP at redline, we called them "dyno queens" because they were never as quick off of the dyno as thier HP indicated thatthey should be.

Another important factor whenmodifying an engine. Often I have seen a mod installed, like exhaust, andthat mod by itself did not increase orsometimes decreasedperformance. Why? Because the engine lost it's tune andif tuned for the mod(s) the true value of the mods were realized. Many performance parts get a bad rapdue to this issue. Just my 2 cents.

 

Thank you all for input and observations. I have always appreciated the knowledge gleened from this site. Thanks again.

Ted

 

TM: Go to Latus HD website; they have a lot of dyno charts with various build/exhaust combinations shown. I wouldn't try to make the comparison based exclusively on absolute numbers, but use the torque/hq curves and the relative change observed.

 

You'll get so much more performance out of ported heads and a matched cam profile that whatever exhaust you choose, you'll be passing so much more air out relative to your HP and TQ gains that the exhaust differences won't be noticeable. Choose the exhaust sustem that you like and get your top end done.