5 replies to this topic

[secretpanda]

Having an issue where it bogs down, around 70mph in 4th, gets to aboput 4500rpm in 4th and just bogs right down, i thinking its a fueling issue?

 

so the build is a 1380, 276 cam and vmax supercharger

 

in 1st and 2nd it pulls hard and revs right up to 7000 rpm no issues, 3rd it seems to get to about 6000 rpm and 4th about 4500rpm

 

so it seems to bog down the higher the load, so would i be correct in thinking its leaning off and fuel stavation?

 

i have a malpassi filter/refgulator and the pressure stays ok. the carbn is a DCOE 45, but im wondering if the jets are too small?

 

sorry i havent listed the jet sizes etc, dont have them to hand at this moment, but was just wanting some advice. i dont think its timing as seems to be fine 1st/2nd gear and pulls very well, idle is perfect at 1000rpm. no pinking or knocking etc, when it does get to about 75mph and bogs down it seems to pop/backfire out the carb.

 

hope someone can point me in the right direction.

 

Thanks

Edited by secretpanda, 25 March 2025 - 04:40 PM.

[sonscar]

This might not sound helpful but you need to know that it is going lean,not guess.An AFR guage is what is really needed to see what is going on.It could also be timing,too much or too little.Boosted engines can be damaged very quickly.Steve..

[enne]

Had the issue with my turbo Mini. The ignition was a bit late, so the exhaustvalve got hot...

 

 Check fuelling and ignition.

[68+86auto]

The ignition needs to be tested and proven to be perfect before you touch the fuel system.

[slidehammer]

My advice would be get it to a trusted rolling road tuner, not just one that does power runs and tells you what your car is putting out. It really needs setting up properly buy someone who understands webers and forced induction etc. I wouldn't keep driving like that or it could do a lot of damage to the engine.

Maybe someone like Vmaxscart could advise as they do supercharger kits

[secretpanda]

problem has been solved, was really underfuling, the kit was from vmax, spoke to stuart a lot about it, will be getting the tune dialed in using a rolling road soon, used a timing light to get that set properly and sorted the main jets in carb, runs so well now