Casper98GT

I have a 98 Gt. I am going to get a new upper intake plenum. When I install, does anyone have any suggestions on what size Mass air and throttle body combo to go with. My current mods are below. Thanks

sfi

Go with the CNL plenum and a 75mm tb. Woke my car up. CNL also has those tru pipes and a 80mm maf for your year car. RPM outlet has
alot of good deals and will save on your wallet. BBK or Accufab are good tb.

04ShakinSteed

Agreed, I believe your year is a 80mm MAF. Go to www.crmotorsports.com for the best prices on the MAF, trueflow pipe and TB.

Casper98GT

Should i go with 70mm or 75 throttle body?

sfi

According to CNL, there 75mm will creat more hp with the new plenum then the 70mm. They have the stats on it if you want to take alook at them. I also read a forum a couple of weeks back with a guy that bought a 70mm and he stated that through the rpm range that a 70mm was
2.5 hp less than a 75mm and that the 75mm lost some hp through the powerband.
I can personally tell you that I have no lose of hp throughout any of the rpm range, and I have a 2002 gt auto/vert.

C&Lperformance.com

04ShakinSteed

75mm it is[sm=smiley2.gif]

2000GT4.6

The guy was me, and even Im not sure if im right or wrong. I have come to think that the T/B was basically a waste of cash though, as according to both C&L and MM&FF (Muscle Mustangs and Fast Fords) the T/B is only good for like 2-3 RWHP. This is compared to like a 10 or 12 HP jump with the inlet pipe and MAM.

You MIGHT be losing HP somewhere in the range (I have heard numerous people say the larger T/B causes air velocity to decrease, thus the loss) but there isnt any way you would notice it, unless you were on a dyno. Its simply not possible for a human to tell a 2-3 RWHP difference.

In the end, I stayed safe and went with the 70 MM, because in any case it still flows better than the stock 65mm one, and if the 65 vs 75 was only 2-3 RWHP, the 70 has to be somewhere close to that. I honestly dont think it will ever really matter though.