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MG MGB GT V8 Factory Originals Technical - I thought I was a smart man...

Some of you may recall my recent posts regarding a miss at 2100 RPM and percieved high RPM levels for my gear ratios (LT77 with 3.07 differential). I believe I solved the second issue.

You know that switch on the back of the tach labeled "4, 6, or 8"? Well, mine was set to "6". Yes, I know, not the smartest.

Now for my follow up question. I typically shift using the tach readings as my guide. Given the issue above, I was shifting much lower in the RPM range than intended. This would lead to putting the load on the engine at around 1500 RPM. Is this so far below the power range that it would result in the stumble previously mentioned.

I am using the RPI Optimax chip.

Thanks, Scott
Scott Miller

"Is this so far below the power range that it would result in the stumble previously mentioned"

Scott
1500 is rather low to change but the factory settings would allow you to pull away at 1000. I don't know how far the optimax chip changes things at the lower end but if you also have a high rise cam you may need to change higher. I change around 3K unless there is a particular reason in which case I might run it up to 3700.

FWIW - Roger
RMW

Roger, thanks for the feedback.

To clarify, I typically initiate the shift at 3000-3500 RPM. Between shifts, the RPMs drop to 1500 as I engage the next gear.

The stumble occurs as I engage the next gear and disengage the clutch.

Scott
Scott Miller

Very interesting. When I shift the RPMs go up. ;)
Carl Floyd

Hi, Carl, That pedal on the right can come off the floor sometime!
John Renaud

Scott, it may just be that you are not shifting fast enough. At the most your revs shouldn't drop more than about 500 RPM between shifts. Are you double clucthing?
If so that would take a little longer. But still,
If the engine is droping down to 1500RPM then I'll bet stumbles. You are asking it to pullaway in ahigher gear from an RPM that is just above idle. Try shifting faster like you are racing someone from a light, I'm not talking about jamming gears and squelling just
quick and smooth, don't let the revs come down.
Chris
Christopher Trace

Chris-

Ideally, I would not let the revs drop, but when in bumper to bumper situations, often I have no choice.

Hopefully, someday I will live in a location (aka not the city) where I can open up the car more often.

Thanks,

Scott
Scott Miller

This thread was discussed between 11/05/2006 and 14/05/2006

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