Biggest Loser...Fit edition.
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From: Minnesota
Hope to get them weighed tomorrow evening...this isn't going to be earth shattering weight loss, but after removing seats and spare it's all about the little stuff. If it comes out to 10 lbs total I'll be happy. Every 10 lbs I drop now is a larger percentage of the total weight than when I began stripping...so 10 lb here and there is a victory.
Again, my next big drop is going to be from a custom aluminum exhaust. This should give me 20-30 lb weight loss. HUGE!!! Then late fall I'll be looking at tossing the OEM seats for lightweight buckets...hoping for 20-30 lb again. That should put me comfortably over 200 lbs of total weight loss.
Again, my next big drop is going to be from a custom aluminum exhaust. This should give me 20-30 lb weight loss. HUGE!!! Then late fall I'll be looking at tossing the OEM seats for lightweight buckets...hoping for 20-30 lb again. That should put me comfortably over 200 lbs of total weight loss.
If you ever end up in west Texas in that thing you had better have a way to stake that thing down to keep it from blowing away..... It's going to be too damned hot to do any wrenching for the next couple of weeks down here.... Ir I am able to handle it I'll be sweating off 6 or 8 lb.s a day.... Of course the water I'll be drinking will put the weight back on me. 100+ heat for the next 2 weeks. It is times like this that a larger A/C, radiator and inter cooler is worth the weight increase.
I didn't reset the ECU after installing the exhaust, but after a few days driving around, that low-end lag I was feeling is gone. The car scoots pretty well, not a huge increase by any means, but it feels and SOUNDS goooood. Dying for that front pipe to mate up to it though. Went to Seeker over the weekend and ordered their stainless braided clutch line, not that this will decrease weight, but it should give the pedal a little better feel overall.
We'll keep this on-topic though and back to the Dick Gregory program.
We'll keep this on-topic though and back to the Dick Gregory program.
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Joined: Apr 2010
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From: Minnesota
I didn't reset the ECU after installing the exhaust, but after a few days driving around, that low-end lag I was feeling is gone. The car scoots pretty well, not a huge increase by any means, but it feels and SOUNDS goooood. Dying for that front pipe to mate up to it though. Went to Seeker over the weekend and ordered their stainless braided clutch line, not that this will decrease weight, but it should give the pedal a little better feel overall.
We'll keep this on-topic though and back to the Dick Gregory program.
We'll keep this on-topic though and back to the Dick Gregory program.
Originally Posted by Tundraforums
The reason that overly large (like 2.5 inch and larger) single exhausts reduce low to mid range torque is they allow the exhaust gasses to expand (which cools them) and to lose velocity. The cooled air is denser/heavier...and the exhaust pulses more or less are merged together further losing their velocity and scavenging action. The net result is the larger exhaust pipes become essentially long tanks of semi-stagnant gas which has to be pushed out by the incoming exhaust...it's no longer self-scavenging. Or, in other words, a larger or dual exhaust has higher effective backpressure than a smaller, single exhaust at mid-range RPM . Yes, the larger/dual pipes have less wall friction on the gasses than the smaller single pipes but this effect is nullified by the loss of energy/velocity in the larger or dual pipes. It's very important to note this situation applies to the mid-RPM ranges...at very high RPM (like near redline), there's enough energy, volume, and velocity in the exhaust gasses to maintain scavenging all the way to the end of the pipes (even duals) and the lower wall friction of the larger pipes does come into play.
Bottom line: for mid RPM ranges, intuition is wrong...there's more effective back pressure (or less scavenging) in large or dual exhausts; for top end RPM, intuition is right...large/dual exhausts have lower backpressure. And at any RPM, backpressure is just plain bad for torque. There's a myth out there that engines need backpressure to make more torque. This is wrong. Backpressure is resistance and you want the least resistance.
Bottom line: for mid RPM ranges, intuition is wrong...there's more effective back pressure (or less scavenging) in large or dual exhausts; for top end RPM, intuition is right...large/dual exhausts have lower backpressure. And at any RPM, backpressure is just plain bad for torque. There's a myth out there that engines need backpressure to make more torque. This is wrong. Backpressure is resistance and you want the least resistance.
The V8 guys have really done their homework. Lots of good info on TQ and exhaust theory.
Based on your measurements SexDrive, I think it's best to stick with 1.75" tubing for all motor, or 2" pipe with heat wrap in anticipation of boost at some point in the future. The purpose of heat wrap would be to hold the heat in the exhaust gases therby preserving velocity and maintaining low end torque...while at the same time the additional pipe diameter should allow better flow at high RPM and yield HP gains.
Last edited by blackndecker; Aug 2, 2010 at 09:27 PM.
Well even on the Fit, if I were one that boosted (highly unlikely on any Honda I own), I would look at 57mm (2.25") or 60mm piping (2.34"). I do believe the exhaust at 50mm (2") will be a bit restrictive, this all depends on how much boost is being pushed through the motor of course. Something like the HKS bolt-on kit with just a minimal amount of boost (.3) I don't believe will find a 50mm restrictive. Then also comes into play is the intake of the motor, if one starts playing around with the intake and head to increase flow, then of course you are going to want to match the exhaust flow as well, where a bit bigger piping will be beneficial. I do believe that a 54mm exhaust would suffice wonderfully in this situation. The stock 45mm piping works for stock setups, but doesn't help when trying to find whatever hidden power lies within the L15.
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From: Minnesota
Good news....the Insight rear drum finally shipped. Hopefully will come in early next week. The turnaround time with Bernardi borders on unacceptable. I realize this is probably a hard to find part, but they could have notified me of the delay.
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THREE WEEKS LATER:
I called Bernardi customer service about the delay (it would be different if they had notified me of a delay...even that my order was received!?!?!...but no...). I asked for free shipping, or at least upgrade to priority, on my next order....but guess what those f@kkers were willing to offer? 25% off of 5 day ground
They offered 25% off of $13.00...$3.25...nothing more! This was a $130.00 order and I was about to place a second $130.00 order with them. WTF?!?!
Never again will I use Bernardi.
/RANT
Hope to get the right side on tonight.
I called Bernardi customer service about the delay (it would be different if they had notified me of a delay...even that my order was received!?!?!...but no...). I asked for free shipping, or at least upgrade to priority, on my next order....but guess what those f@kkers were willing to offer? 25% off of 5 day ground
They offered 25% off of $13.00...$3.25...nothing more! This was a $130.00 order and I was about to place a second $130.00 order with them. WTF?!?!Never again will I use Bernardi.
/RANT
Hope to get the right side on tonight.
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Joined: Apr 2010
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From: Minnesota
Dew eeet!!
If you drive a Sport, this would be equivalent to ~190 lb weight loss (Sport weighs 30 to 50 lb more than base for MT and AT, respectively).
220 lbs is my goal....275 is the dream!!
If you drive a Sport, this would be equivalent to ~190 lb weight loss (Sport weighs 30 to 50 lb more than base for MT and AT, respectively).
220 lbs is my goal....275 is the dream!!
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Joined: Apr 2010
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From: Minnesota
Ultimate weight loss...
Got a crazy idea to reduce mega-unsprung weight...while I was sizing up the Insight rear drum swap (more on that later), I got the crazy idea of trying to get someone to fabricate an aluminum or titanium complete rear axle. The stock steel beam is HEAVY...but the cost of a custom job would probably be $$$$$$$$$$$$$$$$$$$$.
Any thoughts on the pro's/con's of an aluminum or titanium rear axle? I know corvettes use aluminum rear axles...so it should be fine in our little Fits.
Any thoughts on the pro's/con's of an aluminum or titanium rear axle? I know corvettes use aluminum rear axles...so it should be fine in our little Fits.
![Lyon[Nightroad]'s Avatar](https://www.fitfreak.net/forums/customavatars/avatar31469_2.gif){kind=avatar}
Only problem I see is that the rear end stripped down only has 550 lbs on the rear axle per my last CAT scale weigh in. With a front end that weighs 1520 lbs the weight bias towards the front would be pretty wild. Not sure at what point that begins to impart handling.