New header back exhaust. Dyno numbers and 1/4 mile times

[Bosworth Audio]

We just got done making our prototype exhaust for the F50 Q45 with impressive gains

The first round is a 2.25" true dual header back exhaust, all mandrel bent in mild steel for test purposes. The gains were quite impressive on what was measurable. We couldn't get a true dyno run all the way through because of the automatic in the Q, but where we could measure, 3,500rpms-5,800 rpms showed impressive gains.

Our stock dyno showed 252WHP and 268ft/lbs
after the header back showed 264WHP and 281ft/lbs

We couldn't measure the true low end torque, but there is a huge difference which is why we did 1/4 mile times also.

Before:
60' 1.976 @ 32.42638mph
330' 5.972 @ 57.41428mph
660' (1/8) 9.352 @ 73.85625mph
1000' 12.267 @ 84.51481mph
1/4 14.726 @ 92.36089mph


After
60' 1.714 @ 35.06204mph
330' 5.514 @ 59.80051mph
660' (1/8) 8.78 @ 76.33515mph
1000' 11.612 @ 87.08392mph
1/4 13.992 @ 95.14817mph

We're going to try a 2.5" mandrel header back also soon and also look into building headers as these numbers were with a cracked drivers side exhaust manifold and 94,000 miles on our 2002 Q45 test mule with staggered 20" wheels and 275 tires out back.

If there is interest, we will be creating a bolt on kit to replace the front y-pipe setup and the rear section that can be created in stainless or coated mild steel.

[lino]

Well done . How about sharing some pics.

[elwesso]

Very nice, its cool to see theres gains to be had... Was there much difference in the ambient temperature?

10HP on just exhaust is pretty impressive, but seems unlikely that exhaust alone would result in a 0.7 second decrease in 1/4 mile time, but then again if you can feel the difference thats gotta definitely be worth something!

either way, thanks for posting the results!

[Bosworth Audio]

Ambient temp changes, humidity, etc were all very close. This was also done on a brand new mustang dyno. The biggest gain I can feel in the car is in low end torque where it will just light up the rear tires. I will scan and post the dynos. They were done only 1 day apart.

[qship96]

I have a hard time understanding how a 14 HP/13 TQ improvement could possibly lead to a .7 second quicker 1/4 mile time........impossible

[elwesso]

thats kinda what I was thinkin? You would need about 40 HP based on an online calculator I found..

http://www.wallaceracing.com/et-hp-mph.php

Use the bottom thing, I inputted your 14.727 with a weight of 4000 lbs, and I got 248HP, which is pretty much spot on to what your dyno showed... Then inputting 13.992 @ 4000lbs, I got about 289 HP...

The first time seems pretty much spot on where you should be, but something seems strange with running a 13.992?

[Bosworth Audio]

I'm only measuring from 3,500rpms on with the dyno. Yes, they numbers do seem strange, but I'll be more than happy to make a run again with video. The gains I'm not getting measured would be the low end torque under 3,500rpms. I have no way to lock 3rd or 4th gear to measure without it wanting to downshift. Horsepower and Torque are related, but I know for a fact that I picked up way more torque down low.

I'm not saying you have to believe it at all. I'm just posting up what our dyno showed. I'll scan the results today and post them up.

[elwesso]

A little trick some of the older Q guys did was to unplug the TCU when on the dyno, and that would lock into 3rd gear (failsafe) without affecting the engine... Might be worth trying!

[Bosworth Audio]

I'll give that a try this week when we have the time to lock the Q back down. After this we are going to try a true dual 2.5".

This exhaust also removed 2 of the cats, the resonator, and 1 muffler. So there was a lot of restrictions removed in the system while still allowing the pipes to be full of exhaust and carry decent velocity through them.

[marksport]

Any idea on the costs of these headers? Do they still retain the primary cats?

[Rex]

Ar you doing an actual 1/4 mile run or a simulated run on a dyno??

Nice gains nonetheless.

[Bosworth Audio]

It's simulated on the dyno. it's provided very accurate numbers for us on over 100 cars so far.

Headers aren't being made yet, they are a thought that might come to reality. might not

[lino]

Any pics yet?

[Bosworth Audio]

I'll snap some once I get some fiberglass laid on up this Lotus. I'll try and get a few sound clips also

[lino]

Great

[boatdude13]

lies.

[Bosworth Audio]

there was a little bit of vandalism to the car a while ago, so it's been back and forth at the body shop getting new paint and finishing up the airbag system to fit the new wheels on it. I'll have it back in roughly 2 weeks with fresh paint, a new color and will snap some pictures before we start on the new stainless headers for it and redoing the exhaust in 2.5" dual stainless pipes

[Lokim]

thats kinda what I was thinkin? You would need about 40 HP based on an online calculator I found..

http://www.wallaceracing.com/et-hp-mph.php

Use the bottom thing, I inputted your 14.727 with a weight of 4000 lbs, and I got 248HP, which is pretty much spot on to what your dyno showed... Then inputting 13.992 @ 4000lbs, I got about 289 HP...

The first time seems pretty much spot on where you should be, but something seems strange with running a 13.992?

If you look at the 60', 33', and 1/8 mile time and speed differences you'll see where he cut the most time. They indicate a substantial low-end torque increase, which jives with where he says he feels the difference and with the statement of being unable to measure low-end torque gains. If he's reaching peak torque at a much lower RPM than with the original exhaust, his early speed and times will improve, which they did.