H/C installed, no gain.
H/C installed, no gain. Installed Stage I heads, .595 222 112 cam and Katech TC set on 99 C5.
Looking for tips on finding my missing power. I have no dyno, but several roll on tests with a friends identical car (-H/C) results in minimal gain.
The install went well thanks to tips found in here. The only problem area was the pushrod length. The base circle of the new cam was 1.455, so I ordered 7.450 pushrods. When I rotated the assy by hand I found P/V interference. Found that pushrods were .070 longer than stock not .050 as expected, so I made and installed shims under the rocker rails. I ended up with .030 shims. Using .020 the engine would just free spin.
The car runs fine, with a noticable idle, but no power. Ran EFILive before and after and there was no noticable increase in MAF at WOT, tops out at about 34 lbs/min @ 6K rpm. So, the problem appears to be lack of add'l airflow, but why?
Any opinions appreciated.
Looking for tips on finding my missing power. I have no dyno, but several roll on tests with a friends identical car (-H/C) results in minimal gain.
The install went well thanks to tips found in here. The only problem area was the pushrod length. The base circle of the new cam was 1.455, so I ordered 7.450 pushrods. When I rotated the assy by hand I found P/V interference. Found that pushrods were .070 longer than stock not .050 as expected, so I made and installed shims under the rocker rails. I ended up with .030 shims. Using .020 the engine would just free spin.
The car runs fine, with a noticable idle, but no power. Ran EFILive before and after and there was no noticable increase in MAF at WOT, tops out at about 34 lbs/min @ 6K rpm. So, the problem appears to be lack of add'l airflow, but why?
Any opinions appreciated.
TECH Junkie
Joined: Nov 2001
Posts: 3,604
Likes: 0
From: Los Angeles
Re: H/C installed, no gain. </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by DaleMX:
<strong>1.455 BC? Seems a bit high. Sounds like you measured at the lobe.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">With .591 lift, the base circle is gonna be pretty small. Mine are normally around 1.47-1.49'ish
<strong>1.455 BC? Seems a bit high. Sounds like you measured at the lobe.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">With .591 lift, the base circle is gonna be pretty small. Mine are normally around 1.47-1.49'ish
Re: H/C installed, no gain. Thats about it. I thought I would have an air intake this weekend, but the deal fell through. Stock exhaust. Headers will be next (after air intake). I know that I will be leaving some power on the table until I get better intake and exhaust, I was just expecting something.
Re: H/C installed, no gain. well just wait dont get all disapointed yet cause when u do get thoes parts (expecially the headers) that cam will shine <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />
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TECH Apprentice
Joined: Dec 2001
Posts: 351
Likes: 0
From: CA
Re: H/C installed, no gain. </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Pepe LePew:
<strong>Thats about it. I thought I would have an air intake this weekend, but the deal fell through. Stock exhaust. Headers will be next (after air intake). I know that I will be leaving some power on the table until I get better intake and exhaust, I was just expecting something.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Sounds like your car was bone stock, and you put on heads/cam. And your friends car that you raced is also bone stock. You didn't go into much detail on your race with your friend, but you should be steadily pulling on him. I agree though, you need to get some supporting mods on your car, but still, you should have noticed at least 15-20 ponies or so.
You checked your MAF flow rate, did you also check your O2 sensors?
Oh, also, how did you test your pushrod length? Could you answer my question in this post :
https://ls1tech.com/ubb/ultimatebb.p...c;f=1;t=007379
<strong>Thats about it. I thought I would have an air intake this weekend, but the deal fell through. Stock exhaust. Headers will be next (after air intake). I know that I will be leaving some power on the table until I get better intake and exhaust, I was just expecting something.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Sounds like your car was bone stock, and you put on heads/cam. And your friends car that you raced is also bone stock. You didn't go into much detail on your race with your friend, but you should be steadily pulling on him. I agree though, you need to get some supporting mods on your car, but still, you should have noticed at least 15-20 ponies or so.
You checked your MAF flow rate, did you also check your O2 sensors?
Oh, also, how did you test your pushrod length? Could you answer my question in this post :
https://ls1tech.com/ubb/ultimatebb.p...c;f=1;t=007379
Re: H/C installed, no gain. The stock exaust seems to choke the cheet out of H/C packages. I just dyno'd my Stage II H/C with a near stock exhaust, and I only pulled 356 HP. Needless to say, exhaust is top priority now.
Chin-up, at least you have the hard part out of the way. Exhaust is easy to change.
Chin-up, at least you have the hard part out of the way. Exhaust is easy to change.
Re: H/C installed, no gain. </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by akw408
Sounds like your car was bone stock, and you put on heads/cam. And your friends car that you raced is also bone stock. You didn't go into much detail on your race with your friend, but you should be steadily pulling on him. I agree though, you need to get some supporting mods on your car, but still, you should have noticed at least 15-20 ponies or so.
You checked your MAF flow rate, did you also check your O2 sensors?
</font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">You assumed correctly. Both were bone stock before. I added H/C. Also, I should have said my friends "near" identical car, my 99 coupe vs his 99 FRC with 100 lb passenger to account for the weight difference of the FRC.
As far as the race, we just did a series of 2nd and 3rd roll-ons to see Hp differences only. 2nd gear tire spin was a factor, 3rd gear I noticed a slight amount of pull in the top end (1/2 car or less). 15-20 ponies perhaps. From the replies it appears I greatly underestimated the restriction in the factory exhaust, since I was expecting more.
Yes, O2s remained near constant @ ~895 while @ WOT. Before mods O2s were ~905.
Sounds like your car was bone stock, and you put on heads/cam. And your friends car that you raced is also bone stock. You didn't go into much detail on your race with your friend, but you should be steadily pulling on him. I agree though, you need to get some supporting mods on your car, but still, you should have noticed at least 15-20 ponies or so.
You checked your MAF flow rate, did you also check your O2 sensors?
</font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">You assumed correctly. Both were bone stock before. I added H/C. Also, I should have said my friends "near" identical car, my 99 coupe vs his 99 FRC with 100 lb passenger to account for the weight difference of the FRC.
As far as the race, we just did a series of 2nd and 3rd roll-ons to see Hp differences only. 2nd gear tire spin was a factor, 3rd gear I noticed a slight amount of pull in the top end (1/2 car or less). 15-20 ponies perhaps. From the replies it appears I greatly underestimated the restriction in the factory exhaust, since I was expecting more.
Yes, O2s remained near constant @ ~895 while @ WOT. Before mods O2s were ~905.
