You,ll notice that my 60ft. stayed same after the Macs but picked up power in e.t/mph so IMO you might lose some low end tq w/longtubes.Also,some info. about your car would help members give recommendations.

 

the car is a 95 t/a with an M6. The only mods I have right now and a CAI and a flowmaster, but I am getting ready to change the exhaust to an SLP 3 inch catback with a cutout.

 

Definitive proof LT's are better than Mid-tubes
Red = previous setup with mid-tube headers & 30# injectors
Blue = current setp with LPP long tube headers & 37# injectors

 

Nice dyno graph... it is no brainer that lts would outflow mids. Bigger primarys and a straighter flow out back. I still think that the AS&Ms or RK Sports will put down some pretty good numbers with the 1 3/4 primary in the mid style header. Ill know this year in the spring when i get them on to find out how much they net me.

 

For the record, the mid tube headers shown in my graph above were AS&M. IMHO, its LT's or nothing unless ground clearance or emmisions are an issue.

 

Those swearing long tubes are the only way to go.
Are you willing to say my car would gain a meaningful amount with the longtubes?

Going to be another month before I know for sure. Just got 6-7" snow yesterday, tracks wont be open for awhile.

 

So you went from 374rwhp with the as&ms to 384rwhp with lts and bigger injectors. Bigger injectors would play some role but 10rwhp between the two of them insnt a huge difference really. If it was more like 10rwhp+ with just lt's then i could why you would be suprised from the huge difference. Both are good in there own ways im going to try out my as&ms for the year and if i happen to run across a good deals on lt's when i get rdy to drop my new motor in then why not.

 

Yes. Now look at all that new found low end torque. Believe me that torque gets things moving much quicker at lower RPM's.

The injectors are giving me nothing. I went larger to get the duty cycles a bit more on the desirable side. For full disclosure I wanted to mention the injectors and that the current cam has .030" less lift but the same durations. So I may have lost a very small bit there.

 

[QUOTE=95mysticta;5872148]So you went from 374rwhp with the as&ms to 384rwhp with lts and bigger injectors. Bigger injectors would play some role but 10rwhp between the two of them insnt a huge difference really. If it was more like 10rwhp+ with just lt's then i could why you would be suprised from the huge difference. Both are good in there own ways im going to try out my as&ms for the year and if i happen to run across a good deals on lt's when i get rdy to drop my new motor in then why not.

The injectors played role and tuning was involved, I'm skeptical.

 

[QUOTE=lt1-xjs;5872710]Both runs were on a fully optimized tune. Injectors dont make horsepower unless they cant provide the right amount of fuel. AGAIN, the larger injectors work at a 80% DC where the 30# injectors were a tick over 90%. Both will deliver the correct amount of fuel. What you see in the graph is all headers.