Thread: Max safe power on power log and catless downpipe?

Hey Guys,

Trying to decide between doing a full header swap and spending more $$, or just going with a ZZP Catless downpipe and power log front manifold. I am wondering how fast I could go (1/4 mile) with the full header swap vs. just the DP/PLog route. Also wondering what is the safest pulley size I could likely run with the DP/PLog setup. I have HP Tuners and will be doing the tuning myself as necessary...

Granted, I do know that it all depends what other kinds of supporting mods I have on the car, and that this will GREATLY impact which header route would be necessary, depending on my power goals. But just want to get an idea what some of your experience has been with different setups, and what you'd recommend.

**I am ultimately trying to run in the 12's on the best budget build possible. However, I do not want to sacrifice motor safety/longevity too much while doing so.

My current plan was:
Full Headers/DP
Intake
plugs/wires
smaller pulley setup
T-Stat
PCM Tuning (done by me)

Originally Posted by 2007GPGTSC

I run DP and plog. Works great for me. SD headers are the cheapest to my knowledge (ebay) DP and plog will cost about the same maybe more (my DP and plog costed me about 300ish BF sales). The performance to my knowledge is comparable. SD's will ultimately flow better. . . .

Are you running a smaller pulley with the setup? Any idea what power you're making by chance? I know you're running the newer blower...

Generally most of the time downpipe makes more torque vs headers. The max hp and tq number are decided greatly on the tune and type of fuel much more than what mods it has. A safe tune could be way different reg. gas vs say E85.

As Ive said a million times before a downpipe, rocker, E85 car with a 3.4 and a good tune will be much quicker than most people think for pretty basic mods.

Interesting.. I am getting very tempted to just get a 3" catless DP and PLog and see how far I can get with that setup. How hard is it to switch these over to E85? I have been thinking about that route on and off..

I just had to replace the fuel pump this past weekend... Knew I should have upgraded!

Originally Posted by 97AutoXVette

Interesting.. I am getting very tempted to just get a 3" catless DP and PLog and see how far I can get with that setup. How hard is it to switch these over to E85? I have been thinking about that route on and off..

If you can use E85 the better question why are you not!?? Yes its well worth it! 3.4 and pump vs 2.8 on E85 is worth about 60 HP on my car.

Originally Posted by 97AutoXVette

I just had to replace the fuel pump this past weekend... Knew I should have upgraded!

Fuel pump rewire kit and 60#ers would be ok I think unless your cammed, and depending on your mods.

BTW there are at least 2 pumps forsale in the classifieds

I am getting very tempted.. I have E85 available about 2 miles from my house here in Cincinnati. Especially if it sounds as promising as you're making it out to be!

Originally Posted by frosty

Headers > logs and downpipe any day. Night and day difference when you start getting into the 12s range.

Glad to hear it because I ordered pacesetter headers from ZZP this morning!!!

I just e85 swapped my stock gtp. 42# injectors 3.2 pulley and no tuning. Works great but I am out of fuel pump. Need to upgrade mine tonight.

So with 42.5# injectors fuel pump and maybe a rewire kit your saying that no tuning is needed to run a 3.2? If this is indeed the case id be very impressed that the computer is smart enough to make the adjustments with just basically "bolt on" mods. Not saying it doesnt work but im sure there is still plenty left in a better tune vs stock.

Scans from your car would be awesome if you have any dark!

Seems like everyone and their brother should be doing this if its truely that easy..........

Originally Posted by 98GrandPrixIraqVet

So with 42.5# injectors fuel pump and maybe a rewire kit your saying that no tuning is needed to run a 3.2? If this is indeed the case id be very impressed that the computer is smart enough to make the adjustments with just basically "bolt on" mods. Not saying it doesnt work but im sure there is still plenty left in a better tune vs stock.

Scans from your car would be awesome if you have any dark!

Seems like everyone and their brother should be doing this if its truely that easy..........

I might have some scans on my phones.. ill check...

fuel trims are pretty normal. I have a bad vac leak due to being to lazy to fix it and my old vac lines exploding during injector instqll... wot is solid enough with 16 degrees of timing flat and an almost maxxed out maf sensor. You could upgrade the maf a bit to lean it out a bit more and you could run true flex fuel off the stock o2 sensor. The stock o2 sensor will do a 30% adjustment which is just enough to do a e85 to 93 switch if you were not planning on being racecar driver the day you switched back to e85... it takes about 30 or 40 miles and a few key cycles to dial in the fuel trims.

Very interesting.... I guess we may be turning this thread more towards the tuning route now, but since I already purchased headers, nbd!

Does the MAF on these cars simply adjust for the added fuel needed with that small of a pulley? I have the HP Tuners so I can change anything I would need. Also, what size pulley/power level are the stock injectors good for? So you're getting no KR with that pulley and E85 on the stock motor?

Thanks in advance