|
Title: Advice on Diff Ratio Post by: jwm on November 29, 2012, 05:27:37 PM I am running 305 chev, 350 box and monaro rear with a diff ratio of 3.36. It has been suggested that this ratio might be a bit tall. Any thoughts on the subject?
Title: Re: Advice on Diff Ratio Post by: FCRB26 on November 29, 2012, 05:35:33 PM What size tyres you got ?
Are your cruzing on the highway or around town ? what revs is it doing do you feel its revving to much ? Sounds like it wouldnt be to bad if it was running 14 or 15,s Title: Re: Advice on Diff Ratio Post by: jwm on November 29, 2012, 07:08:38 PM Sorry, it's running 15 inch wheels.
Title: Re: Advice on Diff Ratio Post by: Ed on November 30, 2012, 08:23:35 AM have you considered using a TH700R4 box to lower revs on the freeway? 3.36 would be about right IMO Title: Re: Advice on Diff Ratio Post by: jwm on November 30, 2012, 08:41:18 PM Ed, the 350 box has just had a full rebuild but I understand where your coming from.
I'm going to re-assess the situation over the weekend. According to the Tacho (during it's moments of sanity), it just seemed to be revving a bit higher than I would have expected or liked. Having said that, I have just had the SAAS tacho replaced under warranty, it was doing all sorts of erratic things, working, not working, flicking all over the place whilst driving and then yesterday afternoon it just up and died. Had it replaced this afternoon and already the replacement tacho is showing that the car is idling about 300 revs lower than before and it now appears to be very stable. I am now suspecting that it was a tacho issue and not the diff, I'll let you know after the weekend. Title: Re: Advice on Diff Ratio Post by: john253a on December 21, 2012, 03:58:10 PM if you as me if comes down to the OD of the tyre size
std commodore have a 25.5" tyre (give or take 1/4") and with the 700r run a 3.08 or 3.5hsv, and the newer ones run 3.7(or mine came stock with it) i like 3.7 if using the 700r and if the 350/400 3.5 for the street if your still running the 23" tyres 3.36" with a 350/400 sounds nice to me as long at you dont a big stall converter Title: Re: Advice on Diff Ratio Post by: jwm on December 21, 2012, 08:33:22 PM I got a replacement tacho which is far more stable and reliable than the original one I purchased. The tacho readings seem to be a couple of hundred revs lower than was indicated on the original tacho. Unfortunately, it is the wrong time of the year and I've been so busy with family commitments that I just haven't had a chance to go for a long run in it. Thought I might have got out this week for run but an unexpected term of baby sitting a 5yr old and a 2 yr old have put an end to that. Yep, it takes both the wife and I to look after the 2 of them.
I keep looking at my motorcycle in the shed and am also wondering when I will get a chance to ride that again? It hasn't moved for about 7 weeks. That's not to mention the historic bike I'm trying to restore. Pretty sad state of affairs and people have the hide to keep asking me how I fill in my spare time now that I'm retired. They've got be kidding, what spare time. Title: Re: Advice on Diff Ratio Post by: jack_fc on December 21, 2012, 08:48:37 PM Thought I might have got out this week for run but an unexpected term of baby sitting a 5yr old and a 2 yr old have put an end to that. Yep, it takes both the wife and I to look after the 2 of them. I believe you... started work at 4am, finished at 1pm then looked after my grandson (almost 3 yr old) for the rest of the arvo; now absolutely knackered ::)dunno whether its old age or young kids, but it's tough yakka ... (but I wouldn't give up the opportunity to spend time with him for quids :) :) :)) Still plenty of time left for less important things like old Holdens :) |