ScottNM Posted October 22, 2012 Share Posted October 22, 2012 Have not been on here in a while. I went to the track and was VERY disappointed. I purchased a 520hp 467 from a very reputable builder. I was there when dynoed. I do live near albuquerque and the track is at 5400. I figured with altitude loss and going through a th400, I would be about 380hp or so. I have a 2.73 rear and realize that is not good at all for quarter miles. However, this that is the reason I got a bigblock. has CI/torque supposedly around 560tqe. My best was 14.5. I have posi and lost some spinning on take off. I am sure I could lost a half second with slicks but I guess I need 600 hp to get this thing where I want it. Never would have thought it. Not interested in a 3.55 gear, I like the open road. Just thought the motor would get at least mid 13s. Quote Link to comment Share on other sites More sharing options...
CrazyDavey Posted October 22, 2012 Share Posted October 22, 2012 Scott before you get disappointed there is a lot more to it than just a hp number. First the rest of the car has to be up to producing a good number, you also have to consider things like the converter, trans, carburation, ignition, weight...etc...all of this needs to match up to take advantage of the hp/tq. The 2.73's kill it for sure, even going to a 3.08 would help a ton. The 2.73's are keeping the motor from getting to where it can make power. One last thing, the track elevation may be 5400 but the actual air density is much higher than that (what elevation the motor thinks it's at). Looking up yesterday's weather at that track and plugging it into a calculator shows an elevation of over 7100 feet!! Any motor will struggle in that kind of air. The only way to get around it without making the motor too radical would be a supercharger or turbo, sort of create your own atmosphere. Mid 13's is certainly doable but you're gonna have to help the motor some.... Quote Link to comment Share on other sites More sharing options...
dbreese Posted October 22, 2012 Share Posted October 22, 2012 Treed by Davey. Imagine that. I type way to slow. Hey Scott, Don't be disappointed. If you are at 5400' above sea level there is know telling what the DA was. Heck it could have been over 7000'. Given your rear gear and the fact that you are spinning and still ran 14.5 is pretty dang awesome. I would talk with guys that run at altitude and get some tuning tips. Can you post up your incrementals? How was your mph? That is a tale tell sign of hp. Just have fun and enjoy driving that Monte!!! David Quote Link to comment Share on other sites More sharing options...
Mike 57 Posted October 22, 2012 Share Posted October 22, 2012 The gear is killing you. When you had the engine on the dyno where were the hp and torque peaks? You probably are not even at 4000 rpm through the traps. How hard did you run 1st and 2nd out? 1st and 2nd will be your friend with the 2.73. Like Dave said the numbers will come down with some work. Enjoy the challenge! Quote Link to comment Share on other sites More sharing options...
ScottNM Posted October 22, 2012 Author Share Posted October 22, 2012 THANK YOU guys for the feedback. It is very encouraging. This was my first time at a track. OK, I have an ATI StreetMaster Torque converter spec'd to the rear and cam etc with fresh build on trans. Now the dyno was based on open headers and 850 holly. I Have Sanderson mid length headers and also had to reduce carb spacer from 1" to 3/8" spacer to fit under hood and 770 avenger carb. I have new poly bushings on all control arms and fresh shocks. I have sway bars on front and back. Now, specs on best run... 14.534 @ 97.083 mph. Not sure what the rest of this is but here it goes...reactions .684, 11-2.437, 12-6.304, 13-9.490. How much time would I pick up going to 3.08 gears? Quote Link to comment Share on other sites More sharing options...
Mike 57 Posted October 22, 2012 Share Posted October 22, 2012 3.08s would be a help but I can't say what you would pick up. Have you done any tuning to the carb? Quote Link to comment Share on other sites More sharing options...
dbreese Posted October 22, 2012 Share Posted October 22, 2012 THANK YOU guys for the feedback. It is very encouraging. This was my first time at a track. OK, I have an ATI StreetMaster Torque converter spec'd to the rear and cam etc with fresh build on trans. Now the dyno was based on open headers and 850 holly. I Have Sanderson mid length headers and also had to reduce carb spacer from 1" to 3/8" spacer to fit under hood and 770 avenger carb. I have new poly bushings on all control arms and fresh shocks. I have sway bars on front and back. Now, specs on best run... 14.534 @ 97.083 mph. Not sure what the rest of this is but here it goes...reactions .684, 11-2.437, 12-6.304, 13-9.490. How much time would I pick up going to 3.08 gears? Scott, Your first increment is reaction time .684 seconds, second is the 60'(very important) third is your 330', forth is your 660' or eight mile time. Since you are using a different carb and headers than what was used on the dyno tune you have lost some hp/tq. Like Mike was saying a gear change would wake that car up. US Gear makes a reproduction of the 3.31 which was an option on the B/B Montes. It is still a relatively mild ratio and IMHO wouldn't hurt driveability much at all. It all depends on what you want to do with the car and what makes you happy. Unfortunately there are always compromises with street/strip rides. As stated above with some tuning, a little more gear and some sticky tires 13's are in the bag. David Quote Link to comment Share on other sites More sharing options...
ScottNM Posted October 23, 2012 Author Share Posted October 23, 2012 I agree. I love the th400. It is pretty bullet proof for my set up. I would like OD but do not care for OD tranny options. I would love to put 3.42 rear gears with a gear vender behind tranny. Just not an option right now financially, as my wife has cancer. I may just go with a 3.08 gear. Put on MT street slicks and I should be in the 13s I think. Quote Link to comment Share on other sites More sharing options...
dbreese Posted October 23, 2012 Share Posted October 23, 2012 Wow Scott I didn't know about your wife. I'll keep her and you in my prayers. Sounds like you have a good plan for your car. David Quote Link to comment Share on other sites More sharing options...
monte70car Posted October 23, 2012 Share Posted October 23, 2012 I checked the price of the 3.31 gears that Yukon makes $347 and that's not counting the 3 series carrier and internal parts. Quote Link to comment Share on other sites More sharing options...
Mike 57 Posted October 24, 2012 Share Posted October 24, 2012 I have a set of GM 3.31s you would need a 3 series carrier. I think 3.31s were standard on SS Monties. Quote Link to comment Share on other sites More sharing options...
72 LS5 Posted October 24, 2012 Share Posted October 24, 2012 Scott, I've had 2.29 (its true), 2.73, 3.08, 3.31, and 3.73s in different cars. I can totally understand you liking the 2.73 with the wide open spaces out there. I figured I'd put in my 2 cents also. Although a 3.08 gear is a good compromise, I'm wondering if you can get close to that just making a change to a lower profile tire. What tire are you currently running? Going from a 275/60 to a 245/60 is like 1.5 inch height drop - that can be worth like 5 mph highway speed. I have 3.31s now and love them, but when I go to my favorite show every couple months, its a good 1/2 hour highway drive at 3200-3500 rpms at 70-75 mph in the slow lane. You just have to weigh how important that 1/4 mile time is (however often you go to the track) vs comfortable cruising the open road at 80 or so. If cruising is your thing, ask yourself what rpm and speed you are comfortable at and go from there. Like you said, the GV is the solution. I'm in the same boat...one day. Quote Link to comment Share on other sites More sharing options...
vince Posted October 25, 2012 Share Posted October 25, 2012 Scott, The next time you head to the track give me a shout, I would like to see your Monte run. Quote Link to comment Share on other sites More sharing options...
ScottNM Posted November 5, 2012 Author Share Posted November 5, 2012 Will do Vince. Probably spring 2013. I should have a better rear gear by then. Quote Link to comment Share on other sites More sharing options...
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