View Full Version : Injector Sizing for a TA 49

06-05-2005, 07:43 PM
Newbe with a stock 87 GN (hardtop, 105k miles, woman owned before - not raced...).

I acquired a TA 49 turbo. Thinking about 38# or 42.5# injectors. Will be putting on the usuals (Walbro 340 w/hot wire, TH downpipe w/test pipe, 160 degree thermo, adj FP regulator w/gauge, cat back 2.5" exhaust, power plate - have, but not installed, adj waste gate) - basically "bolt-ons". I have a Scanmaster (initial readings good, but idle is rough and doesn't seem to develop full power...)

I want to run 12s, not track it much, but kick some "vette, 'stang, camaro, ricer butt" here in TN, AL, and GA.

Any recommendations on injector sizing? Thanks.

06-05-2005, 08:49 PM
42s are a good choice, as are 60s ... either will give decent headroom for further growth and plenty of fuel.

12s on good gas should be pretty straight forward.

06-05-2005, 08:49 PM
I have Bosch 36 lb/hr "blue top" injectors and I've dipped into the high 11's. Run 12.0 routinely. I have a TA49 and just added a THDP after a few years of the '49 with a stock size ATR downpipe. My track times are with race fuel and fairly high boost. No times in final tune with the Houston pipe yet.

I'm sure either injector will work fine, but I always play conservative. I've found my 36 lb/hr injectors to be just fine.

06-05-2005, 11:00 PM
Thanks guys.

I am going to place an order tonite for the 42s and 340/hotwire kit from Racetronixs. Hope I don't regret getting the 42s instead of the 38s...

06-06-2005, 02:57 AM
They're a common injector and should work well.

Most people think I shouldn't have gone this fast on the 36's already, which is why I enjoy doing it.

I have a set of 009's sitting around for when I want to take things a little furhter. However, that will take a bigger turbo and more wrenching... :D

06-06-2005, 10:04 AM
Be sure to talk to Jack when you call Racetronix ... he'll reassure you that whatever you choose (42s, 60s, etc) will work with your combo.

The key will be a good chip calibrated for whatever you choose ... the 38s are a bit of an "oddball" and not many chipmakers really mess with them a lot.

Most folks use 36s, 42s, 60s, etc. and the chip makers all have those down cold.