Studroes144
TY 4 Stroke God
- Joined
- Oct 30, 2013
- Messages
- 2,897
- Reaction score
- 955
- Points
- 973
- Location
- Lowville, NY Tug hill snowmobiling
Had the chance to dyno my sled today and learned quite a bit. Some details on the sled: 2014 viper, 3800 miles, mpi turbo w/ innercooler, .092" head shim from Allen Ulmer along with his pc5 pti base map, mpi fuel pump upgrade, 430cc injectors from hurricane Dave and a few different mufflers. Our main purpose of dynoing was to compare exhaust options, we had the original mpi quiet muffler, the mpi loud muffler and a custom 2.5" exhaust that I had made for mine over the summer. We wanted to compare the 3 exhaust with a true comparison. While changing between the different exhausts we made no changes at all in fuel and no changes at all in boost. Also we were extremely rich of the afr, 9.0-9.2, lots of potential in fuel tuning but we didn't do any of that just to keep if all the same. First pull with the mpi quiet muffler it made 184 hp at 8 pounds, next pull was with the mpi loud can, this is where it gets good! 202 hp at 8 pounds so right off the bat we gained 18 hp. Put the 2.5" exhaust on and made 2 pulls both at 211 hp, just so it's clear again, no changes made at all other than swapping mufflers and all runs were done within an hour of each other at 150-160 degree engine temp which is true operating temp. So from the quiet exhaust to the 2.5" we got a 27 hp gain! From there we just started adjusting fuel some and getting it closer to the 10.5-11 mark, we are still a bit rich at 10.2 but the final pull was a solid 10 psi at 228 hp on pump gas. Gotta give 2 shout outs, first to Allen Ulmer, I called Allen this past week to see if he had an mpi loud can that would fit my turbo so we could use it for testing. He was pretty sure he had a used one from a project sled that we could and he was gonna send it out. When the can showed up yesterday it was a shiny new one that was shipped direct from mpi, after a quick email to Allen he responded right back and said didn't have the right size one for my gen 1 turbo so he purchased one from mpi and had it shipped direct to me just so we could try them out and I'll send it back to him. That's a stand up business man right there and I'd like to thank him again for putting him personal money out there to do some simple tests that doesn't profit him at all so thanks again Allen! Also need to thank d&d where all the dyno testing was done. They spent 5 hours on a Saturday just to do these tests so that's very much appreciated! Hope u enjoy the info, I personally was shocked by the results and very pleased with the gains!!
