Tri Y or 4 into 1s??

[SUS 5L]

Hi guys,

I had a look through the numerous posts regarding headers but I still can't work out what will give the best HP and torque increases for the minor work that we all do to our LS1s, ie. Diff, edit and CAI.

Tri Ys give better low to mid range and 4 into 1s more high range yes?? I know its debatible but what should I be going for, for just a street car? Is there really that much difference?

[downbylaw]

Hey mate, Ive gone thru the same kinda problem searching and researching endless threads and just got confused. In general try y is good for bolt ons and the 4>1 are if you are going for maximum power ie. supercharged, turbo etc. After saying that though im sure someone else will argue with wat i just said :bash: . At the end of the day i went for paccie try y's and am very happy with it.

[alexcs]

i guess it hinges on your decision to go for the best ET you can with boltons, or just a sweet, well blaanced street car.

if youre all about the ET's, go the 4>1's and a mafless edit, otherwise for just boltons the pacemakers will offer slightly more torque lower in the rev range, but perhaps not the outright power of a 4>1 at the very top end.

this all changes once you start to do headwork and forced induction though.

[Thunder]

What model car do you have and is it auto or manual?

[Cainer]

I myself went Pacemaker 4 > 1... Cant be happier, especially after the 3.91 install she loves the high revs :)

[SUS 5L]

Thanks for the posts guys.

Its a manual VZ SS Ute. I was leaning towards the 4 to 1s then I got sort of confused whether I need tri Ys for street use. I do want to take it out to the track on the odd occasion though.

[Thunder]

Thanks for the posts guys.

Its a manual VZ SS Ute. I was leaning towards the 4 to 1s then I got sort of confused whether I need tri Ys for street use. I do want to take it out to the track on the odd occasion though.

If you go for tri-y or long 4>1 you also need 2 cats (approx $600) plus a set of O2 sensor harness extensions ($130) on top of the cost of the extractors.

You are better off going for a set of short 4>1, expanded cats and larger cat pipes back to the system. That way you are saving on the cats & O2 sensor extensions. The O2 sensor stays in the original position.

Cheers,
Greg

[SUS 5L]

Thanks Greg.

In your opinion what brand is the better. I know theres not too much between them but if price isn't too much of an issue what do you recommend? Oh, and what size should I be going? 1 3/4 or 1 5/8?

[Thunder]

At the moment you can only get 1-5/8" in the short 4>1 which give a good increase in power and torque and are suited for a Street Car. When the 1-3/4" are available, the increase will be at the higher end of the power band and less down low.

[Oztrack Tuning]

I am happy with 4 into 1 in short 1"5/8. Gave the car 13.031 with standard cam and stall and now 11.891/114mphwith a baby cam, stall and still with 3.73 gears (theres more there with 4.11s).

It revs to 6800 easy with this baby cam and must be quite free flowing. Has enough grunt low down to launch in second and do 1.97 for 60 foot.

Also still pulls fine up hill down to under 1500rpm.

There are also many other cars that have good results with the 1"5/8 Tri-Y by Pacemaker.

Steve

[SUS 5L]

Cheers guys. Sounds like I will be going for the 4 into 1s. The car is dead stock and I'm going to dyno run before every mod so I'll let you know how we go. Thanks for your help.

[HacketR8]

SUS L5,

Have a look at my post on CSV 4 > 1's that Greg fitted to my GTO last Saturday.

http://www.ls1.com.au/forum/showthread.php?t=41323