wtmtnterror

Can anyone give me a measurement of the afc spring on a stock 215hp pump?

I Just installed an afc spring kit from tst and the replacement springs were about .75 in. longer than the one that came off the pump.

Also this is not a stock 215 pump, it's a 300hp pump from BD....not sure on what specs. they use to get 300 out of it, probably 191s, and calibrated, but I can tell you that it came with a stock plate moved full foreward, and what seems to be a short afc spring (compared to tst's kit)....

88bird

IIRC on my 180 it was about 1 1/8" you are talking about the spring behind the rubber diaphram right?

wtmtnterror

Yes that's the one, can anyone tell me first hand what kind of performance gains that I can expect with changing out this spring.

I have noticed that I don't have a much smoke on low end as before, also I was hitting 32 psi before with a 16cm nwg, now it spikes around 35.....

displacedtexan

IIRC- the only purpose of the TST spring it to reduce smoke.

wtmtnterror

It does a good job of that, it does seem to be kind of laggy now though...

May just remove the afc foot again and live with the smoke...

Just another question, I see alot of high boost #s...are these being made with stock injectors? I have yet to see over 35 with a 16 nwg, and dyno'd 305/755...

displacedtexan

I don't see how you could significantly decrease smoke without at least some increase in laggieness...

I can hit 36, my plate is centered in my pump...

wtmtnterror

displacedtexan, that is what puzzled me at first, when I removed the spring that came with the BD pump I noticed that it was nearly an inch shorter, but not as stiff as the spring that tst makes.

I have run a 100 full foreward to 3/4 and never seen over 32...

could it be a boost leak somewhere?

displacedtexan

The TST spring is longer and softer, make the foot move out of the way more gradually.

I would think you have a small boost leak if you cant get over 32 with a 100 full forward. Especially with the bigger BD pump.

wtmtnterror

Thanks for the help, I'll start looking for leaks..

Also just for your info looked at the gov arm and it's hitting right at the bottom of the plate...