ScottNM Posted June 16, 2011 Share Posted June 16, 2011 I guess my main reason for asking this question is trying get a general idea of what power is lost going through a TH400 etc. I will not have electric fans either. Anybody dyno at there wheel? Do you know engine block HP prior to install? I am guessing around 50 hp loss. I am quessing my 510hp engine which will be at 6k altitude will be at around 400hp minus another 50 will be close to 350hp at the wheel. What do the experts thing? THanks in advance. Quote Link to comment Share on other sites More sharing options...
Sam (Bones) Posted June 16, 2011 Share Posted June 16, 2011 I was TOLD... a TH400 eats 27% rear wheel horse power is like black magic too! you can get very different results depending on what type of chassis dyno is used too Quote Link to comment Share on other sites More sharing options...
zmanabba Posted June 16, 2011 Share Posted June 16, 2011 Let me start out by saying I am no expert. But I have played one on message boards LOL. Sam is right. Just use the RWHP as a baseline for tuning. I have read posts on independant people dynoing Mark's (VORTECPRO) engines on their engine dynos and have verified his numbers. But a chassis dyno is a different story--I have heard then refered to as reality checks lol. But they are a great tool for tuning and will give you some hard numbers to verify any tuning changes. David Quote Link to comment Share on other sites More sharing options...
FastClass Posted June 16, 2011 Share Posted June 16, 2011 I`d heard about 50 ponies too for a TH400. 27% sounds a bit much as it would increase exponentially(?) according to the HP of any given engine. Quote Link to comment Share on other sites More sharing options...
Winston Wolf Posted June 16, 2011 Share Posted June 16, 2011 My cousin dynoed his GTO on both, he runs a TH400. 505 FWHP on engine dyno 418 RWHP on a Dynojet. That's 17.1% Runs 11.50 @ 115 Runs 10.8 on juice, which made 488 RWHP on same dynojet. Quote Link to comment Share on other sites More sharing options...
680HPStroker Posted June 16, 2011 Share Posted June 16, 2011 I can only speak for a Dynojet chassis dyno, but 17% is about right. Sam and others are right in stating that a chassis dyno is a great tool for tuning to see how efficient your power train is, but your time slip at a drag strip tells the truth about how both you and your car are performing. Dyno sheets are used by a lot of folks to brag, but when you line em up the guy with the big numbers loses at lot of the time. Quote Link to comment Share on other sites More sharing options...
FastClass Posted June 16, 2011 Share Posted June 16, 2011 The 17% number has me sort of curious. That means the HP lose would increase according to higher HP produced by the engine. If you have equally prepared 400`s, then allow for leeching from the rest of the drive train components, I still do`t see how the loss would increase with a higher output motor. Just trying to understand. Quote Link to comment Share on other sites More sharing options...
ScottNM Posted June 16, 2011 Author Share Posted June 16, 2011 Good point. At some point there has to be a maximum loss that would modify percentage. What is discouraging some for me is I have about a 24% corrected HP rating at 5500-6000 altitude in Albuquerque, then add the drive train loss and I think I am looking at getting a 510hp engine to put out a ball park of 330ish to the wheel. Quote Link to comment Share on other sites More sharing options...
CrazyDavey Posted June 16, 2011 Share Posted June 16, 2011 Scott other than moving there's not much you can do about it. Going to a good electronic fuel injection might help some or a forced induction system. Talk to Mark, he's at 6000' too so he knows a ton about compensating for altitude.... Quote Link to comment Share on other sites More sharing options...
JOHNA01374 Posted June 21, 2011 Share Posted June 21, 2011 The twin turbo SBC in my Cutlass made 835hp/896 lb tq on the engine dyno. In the car it made 645 hp and 736 lb tq. Odd that the torque didn't drop off more but the operator said he see's this pretty often. Said the Chassis dyno can apply more load than an engine dyno and if there is one thing turbo cars love it's more load. The Cutlass has a TH400 / 3K converter and a Ford 9 inch with 3.25/1 gears. Quote Link to comment Share on other sites More sharing options...
Mike 57 Posted June 21, 2011 Share Posted June 21, 2011 Every dyno is different. The track will tell you where you are at. Quote Link to comment Share on other sites More sharing options...
MCfan Posted June 21, 2011 Share Posted June 21, 2011 Whoa, John, that makes one bad Cutlass!! Do you have any pics? So when are you going to put some of those pinwheels on your Monte? Quote Link to comment Share on other sites More sharing options...
JOHNA01374 Posted June 21, 2011 Share Posted June 21, 2011 Here is a pic of the engine compartment when I was first putting it together. You can see that there are a number of items still not in place. Ironically I only have a couple of pics scattered around. It's not much to look at yet as it's still stock met brown, tan vinyl top and a black fiber glass hood but it's faster than hell... Notice there is no intercooler... When I first put this together it was going to be a street/show car. I was going to keep everything very mild and only wanted about 500HP. We built the car as you see it without and intercooler as I only planned to run 5-8 psi and I didn't want a huge intercooler blocking the radiator. Well needless to say that simply wasn't enough. After doing a lot of research and talking to a lot of guys I made the decision to switch to E85. Thankfully the only changes I had to make were swapping the injectors for a set of 120's and a simple re-tune. The car now makes a touch over 20 lbs IF the radials hook up. I believe the highest we've recorded was 22 lbs. I have to say I'll never go back to gas on a boosted car. Intake temps in the low 200F range at the end of a pass with 22 lbs of boost... I've considered putting a turbo on the Monte but I swore to the GF that I wouldn't do that to this car. I even have an BW S475 that would be a perfect fit for a 402-454 BBC. I think my plans for the future will be an E-Rod LS3 with a 4L65E trans. I want to keep the Monte a 100% driver with good mileage and reliably. Quote Link to comment Share on other sites More sharing options...
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