car runs slower than i thought

[96darkhorse]

hey guys

i just did my h/c/i swap......i thought the car was gonna run like a raped ape but it actually runs slower than before the swap.....the car isnt tuned yet( made app. for march 2) it obviously has the hanging idle between shifts and sometimes dies cat stops.....the engine sounds good...mechanically i double checked everything at installation and the engine runs smooth...the car just seems like its not moving at the engine's speed.....i have 373s but dont feel them....the pull isnt there...im getting a little backfire once in a while....point blank, the car feels slow......timing is good..im gonna check the maf...what else you think it might be? i mean, you just feel the car is being held back!!!

 

[Stopsign32v]

Baseline pull on my HCI car was 240rwhp after he was done tuning it the car made 328rwhp. Get you a tune.

 

[96darkhorse]

i guess its normal for it to run slow untuned?? im gonna clean maf, check timing and everything else i can think of....i cant wait for tune day

 

[Stopsign32v]

Its the tune man. And if it isn't the tune (which it is) then when they tune your car they will figure out what it is.

 

[96darkhorse]

right on....thanks man...appreciate it

 

[Bullitt95]

No doubt about it. If you do H/C/I mods the engine definitely needs a tune. Even with the tune, yours will probably still feel a bit soft at lower rpm because the real action will only start when you're getting close to 4000. Your old stock head/stock cam/Performer intake combination will be stronger up to that point and that explains why you feel you've lost some power.

 

[final5-0]

I understand your disappointment

After a change as radical as you have done ..........
It takes a while to work all the bugs out :Word:

This may not be well received by some but it is based upon the experience
I found with my sig combo

Way back there in like 2001 when I stated I was gonna run a mid length
runner intake, several peeps poo pooed my thinking and stated I was
gonna loose all my low end

True ... A mid length runner is gonna shift the power band up
however
You got LT's which offer some offsetting to that condition

Also ... Like other members have stated ... A tune makes a huge difference

Most peeps can't imagine what an optimized spark curve can do

It will ... absolutely ... positively ... elevate your powerband's low end

With some thought and careful planning .......
It really is possible for you to have your cake and eat it too

Give yourself some time to get everything all sorted out

Almost forgot ... You said you got backfires from time to time

My Friend

That right there tells you ... Your tune ain't even close

You wait and see ... It will run like a raped ape

Grady

 

[2002BLGT]

did you replace the balancer ? are you sure the balancer ring hasnt slipped ? and what MAF are you running , if you know the timing is right and the balancer hasnt slipped , Id put the stock MAF and 19lbs injectors on it and see how it runs , if it runs good then , you will know how far out of calibration the MAF is ....timing being off and the MAF not being calibrated correctly for the injectors are the 2 biggest problems when doing HCI on these cars ....

 

[ProKiller]

again, wait for the tune before you judge.

my disappointment was unmeasurable when i put in the 331. i upgraded the maf, injectors, boost, new cam, more displacement and it couldn't even get out of its own way. even after a basic tune from Rick Anderson it ran like poo. ended up being the distributor was junk and couldn't hold the timing under load. swapped that out and needless to say i almost crapped my pants when i got on it.

patience, it will get fixed.