Thread: We made a 3`Stainless straight ultra quiet exhaust and WOW, what a difference...

Stick on hood scoops?

Originally Posted by TEK310

i saw that, i assume he bought the car that way.

Yes...

One day they will blow off the hood and I will make a lot of people laugh and it will be good !!
It may not be the ideal way, but it's cheap AND easy way to do it.

I think I will not cam just yet. I will turbo the thing, that will make it run KR free with a lot less Octane because I can run a big front Mount intercooler and get really cool air charge.
If then I need more I will put cams on it. Don't forget once I put the rear engine in, the front traction will be lower as the car will want to wheelie off the ground.
The rear engine is the one I have to jack up a lot of more then the front. All I want is a steady 400HP from the front one.

I was thinking about it and I don't have a choice to go turbo because the supercharger is so powerful at such low throttle that it won't work in tandem with the rear laggier turbo engine.
I have to turbo the front too.

Originally Posted by TEK310

so all you have is 3" exhaust, intake, and 2.8" pulley and you did a 13.3? **** man, you throw in a nice cam like a xp or nic and you will be in the 12s very easily.

On a good track that is a only a few hours away, I will run 13.0-13.1 @ 106 mph with that car. No problems on winter tires.
With drag radials that will bring it into the 12s for sure. Unfortunately my GF made me promise I wouldn't go to the other track today.
But for me, I achieved what I wanted to see, how fast it could be with one engine in a FWD configuration and a small amount of mods.

Originally Posted by txslow6

TwinV6GTP love the way the car sounds. Can you do a cutout on it and head back to the track. I would love to see how much you gain or lose by just opening the exhaust. I know with my S/C setup I picked up 2-3mph with everything else being equal and I didn't have nearly as many mods as you.

I forgot to bring my jack, or else I would have. I was curious too about this.
The total exhaust weight is 44lbs so just that could have helped as well even if there was little power gain.

Originally Posted by killerspeed101

Why no video of track times?

I have the timeslips if you want to see them.

Check this out. That was last night in cooler weather it was a rocket.
0-100mph on that video.

Originally Posted by txslow6

Screw that some nitrous. The community needs some more data with regards to it

Nitrous would work awesome in that card. Cold Charge of O2 !
But it's annoying having to fill the bottle an hour away for me and the fact you have to monitor pressures, install a bottle warmer. Be careful on hot summer days with windows closed etc etc..

Originally Posted by DanPrixGTP

Sure is a quick Prix, I'll give you that.

*Sniff Sniff* - does anyone else smell that? I'm smelling a 2.55"

If I had one negative thing to say about this engine is I hate the fact it has iron heads.
It is the only weakness of this engine when trying to run bigger power on pump gas.

Even with C16 and methanol injection with the 2.8 pulley, I am close to the knock point. I have a 2.6 pulley that I could have used but I fear it is going to give me some knock at this point.
If I run pure 91 octane + meth it will knock. Pure race fuel it knocks. It needs both.

A set of heads is very expensive. I'm trying to keep this project on a reasonable budget.
So what I'm thinking about now is making the switch to E-85. That will take care of the air charge temp problem and take care of the knock prone iron headed 3.8 all at once.

I installed the 2.6 pulley today after machining the snout.
We saw an approximate 20-25 HP average gain that showed on the acceleration as well.
I also tested different shift points and we found 6300rpm shift was best for a quick acceleration.
The stock engine and stock heads are of course out of breath past 5800rpm but the big drop in RPM when shifting to the other gear is a bigger problem than this.
We gained .2 seconds on our test run from shifting at 6000rpm to 6300rpm. the test was done by doing a 0-90mph acceleration in the same manner each time.
Then checking the 40-80mph time and comparing. At 40mph traction is good now that I've perfected the launch. So from 40-mph is a good test of time lost in the 1-2 shift.

I was still running a stock timing map. Now with a slightly more aggressive map I still have zero knock and it seems to pull harder. Unfortunately my S/C belt started slipping at high RPM so the gains were offset by this.
Tomorrow we are putting on a shorter belt and possible rigging up a belt wrap arm of somekind if we still slip.