iistevo84ii Posted July 22, 2005 Share Posted July 22, 2005 In my quest of narrowing down what exactly I want to do with my car (performance wise), I came accross a bump in the road. Many of you talk about how you rarely use 1st gear in your T56/V8 combo, and I also realize many of these are HIGH HP engines. Well one of my ideas was to buy a crate engine (many of you may rather build an engine, and its not that I could't, but having the peace of mind of proffesional assembly and warrenty really impress me). The one I was looking at was a fairly stock engine puting out about 290hp/330tq. THis is where my question comes in.... If my memory serves me right, alot of the T56's where matted to cars with 350+ hp and tq. So with keeping the R200 (3.54) and using that engine, would that combo work?? What Im saying is, would the gearing be "good" with that amount of HP/tq, or would I be better off with a different tranny?? Any light that you can shed on this would be greatly appreciated. Other advice/comments are welcome too. Quote Link to comment Share on other sites More sharing options...
Tim240z Posted July 22, 2005 Share Posted July 22, 2005 The T56 will work fine with that setup, but just ask yourself if the $$ for the T56 is worthwhile. With that diff ratio you will use the 1st gear, but rarely 6th. The T56 is a big, heavy unit......since you don't need the strength (conservative HP levels), go with a WC T5 and save your money for other stuff. Quote Link to comment Share on other sites More sharing options...
Tim240z Posted July 22, 2005 Share Posted July 22, 2005 Oh..BTW: Quote Link to comment Share on other sites More sharing options...
BrandonsZ Posted July 22, 2005 Share Posted July 22, 2005 But I like the idea of a 6 speed so I got one. I'm planning on using 6th even with the 3.36 stock R180 rear and .5 ratio, it will turn 1470 at 65. Plenty of torque to do that, 6th will have similar performance to the original 4th according to my setup calcs. I'll only have 70% more torque in 1st than original due to the 2.66 1st (compaired to 3.55 original 1st) which shouldn't shread the R180 too quickly. I could stand the 3.54 though it would raise the RPM to 1556, probably a noticeable difference. I'll keep it sane though and I plan on beefing up the diff mount and frame rails. The Firebird/Camero T56 has different ratios though 2.97 1st and .62 6th. .62 6th witht he 3.36 would be 1823 at 65 and 3.54 would be 1920, almost 2k, I like the low rev idea myself, at 80 my setup turn just over 1800. Quote Link to comment Share on other sites More sharing options...
Bartman Posted July 22, 2005 Share Posted July 22, 2005 I have a similar setup and I like having the sixth gear. If you like cruising at high speed it really comes in handy. I was driving around on the freeway yesterday and I was tuning around 1800 rpm at 70 mph. If you're more into racing than cruising then I would save the weight and get a 5-speed. Quote Link to comment Share on other sites More sharing options...
Phantom Posted July 22, 2005 Share Posted July 22, 2005 I've got over 17,000 miles on my set-up right now and I can tell you that 330 lb-ft of torque will work with any ratio between 3.36 and 3.70. At 60mph in 6th you'll be turning about 1,500 rpm with 3.70 gears or about 1,350 with 3.36 gears - assuming stockd diameter tires. I've mulled this one over until I got a headache and have decided I like my 3.70 ratio. I have to watch it to keep from melting the tires in first but man does it kick butt when I hit third at highway speeds! Quote Link to comment Share on other sites More sharing options...
BrandonsZ Posted July 22, 2005 Share Posted July 22, 2005 I think bartman has the spread ratios .62 6th. That would explain the 1800 at 70. But 1350 at 65 does not sound right, you must have 3.36 rear to be turning 1500, not 3.70, the 3.70 should get you . Or your tach may need a slight adjustment? Are you using the stock gage? IT would be pretty easy to get it off a bit if you adjusted it on idle. With 185-75R14 tires right? Let me know if I am making an error. .50 6th + 3.36 rear and stock tire size = what RPM? I think 1500, Phantom says 1350. Quote Link to comment Share on other sites More sharing options...
Tim240z Posted July 22, 2005 Share Posted July 22, 2005 No....Bart has the 50% OD and a 3.54:1 rear....don't know the tire size. His speedo may need recalibrating due to the initial calibration being done with 245/45-16s, so depending on the difference in circumference, that could be throwing it off..... Quote Link to comment Share on other sites More sharing options...
Bartman Posted July 22, 2005 Share Posted July 22, 2005 My numbers are just an approximation and I do need to recalibrate my speedometer. The speedo was calibrated on Tim's car with 245/45-16s and I have 225/45-17s. I did enter the tire sizes into an auto tire diameter calculator and surprisingly the diameter is pretty close. 245/45-16 = 24.68" diameter 225/45-17 = 24.97" diameter Quote Link to comment Share on other sites More sharing options...
BrandonsZ Posted July 25, 2005 Share Posted July 25, 2005 No....Bart has the 50% OD and a 3.54:1 rear....don't know the tire size. His speedo may need recalibrating due to the initial calibration being done with 245/45-16s, so depending on the difference in circumference, that could be throwing it off..... Cool. Looking forward to my R200 then. Quote Link to comment Share on other sites More sharing options...
Phantom Posted July 25, 2005 Share Posted July 25, 2005 My numbers were with the .50:1 OD 6th T56, 3.70:1 R200 LSD and 225/50-16 tires - both actual and mathed - using exact gearing, tire diameters, etc. The 225/50-16 tire is very slightly (2%) larger than the stock 185/70-14 that came on the 280Z. Quote Link to comment Share on other sites More sharing options...
BrandonsZ Posted July 26, 2005 Share Posted July 26, 2005 My numbers were with the .50:1 OD 6th T56, 3.70:1 R200 LSD and 225/50-16 tires - both actual and mathed - using exact gearing, tire diameters, etc. The 225/50-16 tire is very slightly (2%) larger than the stock 185/70-14 that came on the 280Z. http://www.geocities.com/z_design_studio/transmission.html It don't add up. My numbers match this site. Quote Link to comment Share on other sites More sharing options...
GabeRoc Posted July 26, 2005 Share Posted July 26, 2005 i just ran the numbers at 60 mph with .5 OD 185-75-R14 tires: 3.36 rear 1359 rpm 3.54 rear 1432 rpm 3.7 rear 1497 rpm 225-50-16 tires: 3.36 rear 1363 rpm 3.54 rear 1436 rpm 3.7 rear 1501 rpm so, if the tach and the speedo were just slightly off then 1500 at 65 with 3.7 would be right. then there is the question of do you read the top of the needle or the bottom of the needle... anyway, gabe Quote Link to comment Share on other sites More sharing options...
Phantom Posted July 26, 2005 Share Posted July 26, 2005 Now that is really splitting needles! Quote Link to comment Share on other sites More sharing options...
BrandonsZ Posted July 27, 2005 Share Posted July 27, 2005 Oh, now what a waste of thread, I meant "65" not 60 or 55. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.