[VetteAholic]

Alright Gents don't give me **** for asking this

The reason I am asking is because the threads that I have searched up tell the person that it's either not worth the money on stock motor or first mod then tune, etc etc.

Well, hell the question was what are the HP GAINS!?!?! Nothing else.


I took my C4 to the Dyno other weekend, 1992, 167k miles to the motor. Current mods: CAI (Cold air intake), Factory exhaust manifolds Catless, X-pipe, Borla Stingers. 52mm BBK TB. 26LB HR injectors (+2LB HR over stock)

3 dyno pulls, my C4 made 242 RWHP and 272 RWTQ. ( I was hoping a bit more but oh well)

I have 2 shops that can perform a dyno tune and I will be getting a deal from them due to sponsoring a Corvette club I'm in.
So I'm asking "What is a realistic RWHP gain from a tune based on the mods that I listed"?

Thank you.

[toobroketoretire]

There was certainly no gain by using the 52mm throttle body as the stock throttle body will flow all the air your stock engine can possibly consume. And you're likely running too rich because of the higher flow rate of the injectors unless you dropped your fuel pressure to compensate for them.

I would think a skilled tuner could give you a lot more power after running a few tests.

[VetteAholic]

Originally Posted by toobroketoretire

There was certainly no gain by using the 52mm throttle body as the stock throttle body will flow all the air your stock engine can possibly consume. And you're likely running too rich because of the higher flow rate of the injectors unless you dropped your fuel pressure to compensate for them.

I would think a skilled tuner could give you a lot more power after running a few tests.

Yeah, I was thinking about swapping out the BBK over to the stock one, I still have it.

I would have thought I was running rich, turns out the dyno test came out opposite of that, I was running a bit lean. I'm not really informed with some of those numbers that printed out. For example my A/F ratio says here: (LAMBDA) 1.234.

[fishslayer143@yahoo.com]

just don t be too disappointed if its not big gains.. a dyno pull is just a baseline for future improvements..you can see if what you do increases power.. every dyno will give a little different result...

[Snowweasel]

Keep us informed on how it works out ,I'm thinking of doing the same to my Baby

[slrvette]

i agree the TB is no gain. Your better off throwing the old one back on.
The injectors are larger... If you've made no adjustments to your tune to compensate for those then you probably will be running rich.
These bolts on are hurting you.
I can't remember what the hp/tq numbers are on a 92... but I do believe your in line with what you got. Those mod's imo have no given you much gain at all.

[toobroketoretire]

Originally Posted by slrvette

i agree the TB is no gain. Your better off throwing the old one back on.
The injectors are larger... If you've made no adjustments to your tune to compensate for those then you probably will be running rich.
These bolts on are hurting you.
I can't remember what the hp/tq numbers are on a 92... but I do believe your in line with what you got. Those mod's imo have not given you much gain at all.

I have never known of a single instance in which any of the car or truck manufacturers used carburetors or throttle bodies that were sized too small for the breathing capabilities of the engine. Same goes for injectors as the stock injectors can easily flow more than enough at the recommended pressures. In the CrossFire days it was found the stock in-tank fuel pumps couldn't maintain enough pressure after about 3000 rpm but that was corrected in the '85's and up when better constructed higher-amperage pumps were used.

[Theo]

I would put long tume headers on the exhaust

[Theo]

sorry I mean long Tube Headers
I changed my diff ratio to 3.73:1 and boy oh boy....good rear torque and 1/8th mile acceleration also very good! Its a bit thirsty now though..

[VetteAholic]

Originally Posted by Theo

sorry I mean long Tube Headers
I changed my diff ratio to 3.73:1 and boy oh boy....good rear torque and 1/8th mile acceleration also very good! Its a bit thirsty now though..

And I still don't see an answer to my question LOL

Long tubes are on the to do list.