Ok here is the scenario.



Local kid has a 88 GXL, motor is N/A and he is looking to get a lot more power out of it, without going full bridge if possible. I am not an expert on the N/A power levels nor what it takes to make around 250 hp in one. So I pose this question to the experts, without using a turbo what would it take to reach these numbers? This will include port work, sleeve work or removal, fuel system upgrades if needed and any other information you can provide.



Thanks

bascially if you street port a 4 port block (t2) with the 9.7 rotors, and a big weber you're looking at 220ish rwhp. if you want more you need to bp it

rotaryman was telling me someone he knows had a street port 6 port engine with haltech tuned to 280hp i thought...i forget the details though..

any estimations on hp numbers with the higher comp renisis rotors?

You will probably not get to 250 HP in an N/A without Nitrous. And you will definitely not get it to the rear wheels without it. You have much less HP at the rear wheels than you have at the flywheel.



The shot of nitrous you would need would probably be bad for the engine. You are talking about an engine that has 146 HP stock and that is not at the rear wheels. Even with new intake, new exhaust, ignition, you are looking at maybe something in the 160's. It is less than that at the rear wheels. You are looking to get an extra 100 HP out of that, so you do 100 shot of nitrous which gives 100 HP to the rear wheels but that would only give you 230 or so at the rear wheels because of the power loss through the drive train. It would be close but maybe possible.



I would love to hear what was on that haltech tuned 6 port. Also, can the GXL drivetrain handle that much HP?

A board member running FE rotors says he gets 24 RWHP more from the 10:1 rotors but I dont know if he was using 9.7 or 9.4 before.

still nice, either way

If you can only get 160HP out of a stock port engine utilizing a new intake, exhaust and ignition you are doing something terribly wrong or either the combination of parts suck. This is assuming your engine is in good shape. Everything has to work together.



A good FI setup(racing beat upper with some TWM throttle bodies come to mind) and open exhaust(but still using mufflers) should get you around 180 with proper tuning on a stock port motor. Mildly port that same engine and prepare it to run safely at slightly higher RPMs and your around the 200HP mark. Bridge port that engine and clearance it to run even higher RPMs and your around the 230HP. Granted, all these numbers will vary depending on the ports ability to flow and the ability of the person tuning but these are very attainable numbers.



Now you might be asking wheres the proof? There are cars out there that make these numbers but they are far and few between and the reason for that is most ppl don't spend the needed money on tuning. Sure they got all the go fast goodies but haven't paid for the tuning.



Damn, my replies are always to long. Sorry.

Free flowing/true cold air intake

Half bridge port (I know you wanted to avoid a full BP)

Exhaust port and sleeve work

Header

A good exhaust system

Higher compression FE rotors

Motec or high end ECU to tie it all together.

Bigger injectors 550 primaries and a little larger than 720 secondaries

Walbro 255 fuel pump



And a whole lot of money...



This might dyno 250 on a cold day https://www.nopistons.com/forums/pub...#>/biggrin.png



The drive line is not beefy enough to handle 250 for too long though. This would be a labor of love cause it would be cheaper to go turbo in the long run...

Dyno information for a stock port engine



This guy has simply added some bolt on goodies and tuned it properly.