Mazda Rotary Club

General => General Technical => Topic started by: Jot17 on August 01, 2012, 02:59:29 PM

Title: Slight Hesitation Between 4000rpm & 5500rpm
Post by: Jot17 on August 01, 2012, 02:59:29 PM
Hi guys,

I\'m new to rx7\'s ive just brought one a few weeks back it\'s a 1996 fd3s twin turbo and I have a slight problem with it. The problem is when I put my foot down in 3rd gear below 3000rpm when it picks up it\'s fine but until 4000rpm there\'s a slight hesitation it\'s between 4000rpm and 5500rpm I have read up and at 4500rpm the second turbo kicks in, is that why it hesitates? It doesn\'t drop speed or drop revs it\'s a split second hesitation it happens only in 3rd 4th and 5th gear it does do it in second but it\'s really rear, doesn\'t happen at all in 1st gear.

Would you guys know what it might be?

Thank You For Reading My Problem Hope You Guys Can Help

Thanks
Jot
Title: Slight Hesitation Between 4000rpm & 5500rpm
Post by: HaywardRotary on August 01, 2012, 05:45:03 PM
Hi Jot,
That is normal for twin turbo operation.
When the primary (1st ) turbo is about to change to twin turbo operation it has to prespool the second turbo to get it up to speed so some exhaust gas is bled from the first turbo to do this and it slows a small amount thus reducing boost pressure slightly and that is in the part of the rev range you are talking about.
regards
Carl
Title: Slight Hesitation Between 4000rpm & 5500rpm
Post by: Jot17 on August 01, 2012, 05:49:13 PM
Quote from: HaywardRotary;831163Hi Jot,
That is normal for twin turbo operation.
When the primary (1st ) turbo is about to change to twin turbo operation it has to prespool the second turbo to get it up to speed so some exhaust gas is bled from the first turbo to do this and it slows a small amount thus reducing boost pressure slightly and that is in the part of the rev range you are talking about.
regards
Carl

Hi, thank you carl, that\'s a relieve I thought something might off been wrong with the car but glad there isn\'t, carl is there anything that you would advise me to keep my engine healthy, I\'ve done a service and I called you guys up to ask where a bouts the spark plugs were located, I\'ve changed the brake pads as they were nearly finished, so is there anything you could advise me to check? I still need to change the spark plugs.

Thank You:)