Combo change.. Track Heat Intake and 3.90's (I drive on street more than track)

Pokageek

Active Member
Jun 10, 2005
2,767
0
46
MA, USA
Hi Guys,

(or 4.10's) My tuner told me changing to Track Heat intake and lightening MAF will give me more HP so...If I do that and change to 3.90 gears do any of you experienced folks have any guesstimates of improvements in E.T., HP output and driveability? On the driveability side, I figure raising the gears will offset any low end loss to the track heat intake. In general will the car still have low end with this change? ..I mean, it kinda seems I am just playing with rpm..but does that really make more power?

Last, I forget..does the track heat intake require a larger hood or can the stock hood be used (with 3/8 inch spacer).? Thx.
 
  • Sponsors (?)


I think the track heat upper might benefit you. Have you had a dyno run? If so, look at your curve. I have a similar combo, and my hp curve seems to truncate at about 5000. It's great for a nice wide flat power curve. But not very peaky, and definitely leaving some top hp on the table. So I think the track heat would definitely give me 5 to 10 more hp up there. Don't know what it would do down low, but I have LT headers so I get plenty down low any way.

On the gears, I would stick with your 3.55s. Especially if you have any thoughts of supercharging or other power adder down the line. I just went from 4.10 to 3.73, and am much much happier with the 3.73 gears. The 4.10s were fun, but 1st was truely meaningless, and top end was also shorted out. 3.90 gears are kinda wierd IMHO. You cant get Ford Racing 3.90s, and they are so close to either 3.73 or 4.10 that you prolly won't notice a difference if you were to compare 3.90 to either 3.73 or 4.10 (it's like 5% either way!!). So you should just consider either 4.10 or no change. I would guess that the difference between 3.55 and 3.73 would be minimal in SOTP too(again just 5%!!).

So my suggestion would be to do the street heat upper alone. THe MAF and a 70mm TB might help too. Then if you really feel like you need more down low, then get some LT headers. Then if you still need more, then bolt on a super charger. (Man it's fun spending other people's money)
 
Go 4.10's.

You will have plenty of low end with the track heat. With 4.10 gears it won't be an issue. A cam swap will do you wonders!

I have 4.30's in my street car and first gear is far from useless :)
 
i have the Pro 5.0 3.90's and i could tell a difference bt the 3.73's and 3.90's. 4.10's i dont know i havent been in a car with 4.10's. the 3.90s are doin great though..they are just as quiet as can be, but its up to you mang, i got the 3.90s because i just wanted to be a little different, but dont let folks who have never seen them or dont own them tell you they suck. from experience they are pretty damn good.
 
On the allford mustang gear calc those 4.10's rev the car out to 145 in 5th so I guess I don't see where the top end is lost other than high revs on the bway.

3.90's are a little better for HWY, like 200rpm @75 that does make a diff. A tremec with .64 OD will move it down to 2450@75mph which is right where I would want it eventually.

Here's why I am discussing these options:
#1 Nitrous is out. O don't want to have to rely on juice everytime I floor it and be disapp'd when I am out of juice and lose my power. I want the power there all the time.

#2 Supercharged is awesome but the trans would require upgrading immediately and between that and the SC, that is easily $3k+.

#3 Better gearing and an intake would cost me like $750 and should make a dramatic improvement..like 12's based on what I am hearing and not require an immediate trans upgrade.

Cost vs. power in the short-run, like 1-2 years, #3 makes a lot of sense right now.
 
Pokageek said:
Last, I forget..does the track heat intake require a larger hood or can the stock hood be used (with 3/8 inch spacer).? Thx.

My edelbrock performer with a 3/8" spacer was touching my stock hood. I could have cut some of the hood away, but it wouldn't have looked as good as what I have now. I think the track heat is taller than the eddy, so you're probably gonna need a new hood.
 
Pokageek said:
On the allford mustang gear calc those 4.10's rev the car out to 145 in 5th so I guess I don't see where the top end is lost other than high revs on the bway.
That's true, but that's redline in 5th gear. 5th gear is not an acceleration gear and does not tolerate up shifts well from 4th at redline. Trust me, I had 4.10s, and I know it does not work well up there. Look at top speed in 4th for your useable top end.

drakesdad said:
I have the Track heat set up and it's close but my stock hood with the firewall still on shuts and closes fine...I have heard other people say the removed the firewall, it touches on mine but does not cause any problems....
Will
I think you are referring to the fire blanket. Removing the firewall would be a rather large project.
 
GRGT1994 said:
That's true, but that's redline in 5th gear. 5th gear is not an acceleration gear and does not tolerate up shifts well from 4th at redline. Trust me, I had 4.10s, and I know it does not work well up there. Look at top speed in 4th for your useable top end.


I think you are referring to the fire blanket. Removing the firewall would be a rather large project.
BLANKET=WALL=WHO GIVES A SH4T.......LOL
I didn't realize what I typed until I read your thread....must have been thinking about the other post about quickest way thru the firewall.....
Yeah, I am going to remove the firewall with a torch to take some weight off:D
 
HAHAHAH!!!!!!!!!!! Yo uguys are cracking me up!!!

p.s. Thanks for that info on the upshift to 5th GR. I had no idea about that.

p.s.s., I like the idea of the longtubes too but me don't think they wrk well on verts.

I ordered the 3.90's and the track heat. Think I am starting to max out my combo to its best. Will report back.
 
I know of one 'vert in particular that works fine with LT headers (mine that is).

BTW, I had a ball with my 4.10s while I had them. They were wicked fast to shift. So you should likewise enjoy your 3.90s too. For me, I just prefer the 3.73s for the slightly longer runs. That and I dropped over a half a second in 0 to 60, due to the one less shift (50 to 55 maxed into redline with the 4.10s). Enjoy.
 
i had 4.10s before. 3rd gear and 4th gears are a blast, but 1st is basically nonexistant and 2nd isn't much better. think about having to shift into 3rd to cruise through the neighborhood at 20-25 mph

plus the speedo and odometer are way off with 4.10s

not for me. 4.10s are ok on an auto tranny tho
 
Just some more #'s...

According to the calculator, in SECOND gear, the 4.10's are @6400 at 60MPH vs the 3.90's @6094. For 0-60, the 3.73's and 3.90's only need 2 shifts and stay in the power zone.

On the HWY, the 3.90's seem around 150rpm lower on avg. That does give hwy drivers significant more room in the RPM in my-o. Quarter milers are going to be better with 4.10 and up.

"I know of one 'vert in particular that works fine with LT headers (mine that is)."

Did you have any trouble fitting them?