rpmauto

iTrader: (14)

I was looking for some more imput on going with bigger headers. I currently have the tpis 1 3/4" long tubes, very nice coated look just like the day i put them in. Well I had them on the stock motor and now i have a 402. At the end of the build it kinda turned into budget as i completely repainted the car at the same time. I make ok power, but not as much as i was hoping for. I have tsp ls6 stg 2.5 heads. How much am i leaving on the table?? I will someday be upgrading the heads, but i want to get the most out of it with these heads. I wont do heads till i have the car dialed the way it is. Is it worth the cost for what i will gain going to the 1 7/8" headers. I think my tpis headers are a good product. I read someplace that katech used them 0n some of their motors with good success. Would i have to retune after going with bigger headers?? Thanks for your input in advance.

conan

iTrader: (5)

Check this thread out. I think you would have alot to gain on a 402 with heads and the cam in your sig.
https://ls1tech.com/forums/generation-iii-external-engine/981229-stock-motor-1-3-4-vs-1-7-8-engine-dyno-results.html

Sales2@Texas-speed

iTrader: (5)

There was a guy who went from some 1 3/4" headers (sorry I don't remember which brand) to our 1 7/8" headers on his 402 engine and gained something like 25rwhp!

BlackScreaminMachine

iTrader: (17)

Yea, I have seen a gain too, then that same motor on n2o runs 9.50's went to a 1-7/8 to 2" and didnt see much gain at all.

rpmauto

iTrader: (14)

That is what i am hoping for, if i could gain 25rwhp it would be worth the swap, I am happy with how the car runs, i am just looking for some cheaper alternatives to make the power it should.

slow trap

iTrader: (22)

some combos gain and some may not. i'm still on 1 3/4 headers.if i knew there would be a realistic gain i would think about trying out a 1 7/8 but i just don't see my combo gainining anywhere near 20-25 rwhp. on the jug is really where a big tube helps get rid of all that extra cylinder fill so i'm still debating on the switch.

ndfrsd6

iTrader: (5)

i had 1 3/4 hookers on my 402 with a 78mm fast from my h/c setup , i put down 475 rwhp and 440 tq. when i went to a 1 7/8 hooker and a 90/90 setup and put down 500 rwhp and 469 rwtq imo its worth it

06black6spd

now that is a good significant gain, wow

rpmauto

iTrader: (14)

Yeah, i want to get some good n/a times with the car, but i love the jug at the track. I guess i will start saving for the next things, driveshaft, headers, rims for slicks. I am happy with the heads i got from tsp, i just will always wonder how much better an aftermarket casting would be. I am going to run with these for a few years and then maybe afr, or trick flow.

Tom@ARH

I also think your setup would benfit from the 1-7/8's you'll definately need them if you spray. At this point it does'nt look like you went the cheap route. If your looking to not leave anything on the table buy the right part the first time.

rpmauto

iTrader: (14)

yea, i didnt go the cheap route. those tpis headers when i bought them $$$. Around $700 i think, i will have to look up the reciept. And then $300 for the crapiest y pipe setup i have ever seen. I now have a pacesetter y and it is better than the tpis one, so that doesnt say too much.