SS 98

Hi guys, I'm living in province of Quebec and we don't have the same good resources like in the states for any car mods! I go fast : I've a friend having a moded Camaro SS '98 with LS1 engine and 4L60E tranny, 3.23 gears! Owner since 2003, he do drag race each summer but back 6 years ago the car is not able to do the same time on the quarter mile, and after changed some parts, the problem is still not fixed!

The car was steady around 13.00-13.20@108-110 mph on street tires, but since summer 2006 the car run 13.50@98-100mph!!! WHY?


The mods : -Edelbrock 1 5/8" headers
-K&N ram air kit
-Hypertech hand programmer
-Ported OEM heads
-Cam Comp Cam part number 54-412-11


The check engine light on in 2006 for some troubles : -knock sensors
-O2 sensors
-MAF
All the faulty parts got changed but the car is still not able to redo the good times at 13.00@110!!!

Sorry I'm not a perfect bilingual and I hope you understand this topic, thanks f-body guys!

Hemi2Slo

Well the hypertech with cam and ported heads is scary. The car may have just lost a step from running lean for so long. I would adventure to say the car would live longer without the hypertech since it tends to lean the tune out from what I've seen.

BLK02WS6

iTrader: (2)

Hypertech on a heads/cam car is a huge problem! It needs a proper tune for those mods, not a Hypertech... Hopefully it isn't beyond repair, but if he has run it much, it may be...

SS 98

ok guys, thanks a lot for these informations, the car is now back to stock programming! do you know how much miles he must to cover with the car to allow the computer to remake new fuel&timing tables if the progammer has its own programming? the programmer is an Hypertech #380752! and I forgot to say you that the fuel pump has been changed for a Walbro 255 3 years ago!

BLK02WS6

iTrader: (2)

It is still going to need a proper tune...

Sladester2

iTrader: (1)

It needs dyno-tuned

SS 98

yes you're right guys with the dyno tune, but there's not a lot of good resources here in our province, you're better a lot than us in the mods and tuning!!! I'll pass on your answers at the Camaro's owner, thanks again, we appreciate that!

SS 98

I forgot a little detail : as the OEM cam got changed for the Comp Cam, part number 54-412-11, earlier in summer the owner realized that pushrod was curved 'cause the roller bearing of the rocker got broken! then he changed for new ones but with new roller rockers 1.8 too! is it safe for piston-to-valve clearance? and do you think that with the OEM 1.7 the springs valve got coilbind?

SS 98

Ok guys, this story is a litte bit far away for you, here the news : on may 8th , we did all the basics tests again on the car, all is ok! I removed the Hypertech programming for dyno runs : without hypertech the car made 306 whp and later with hypertech reinstalled the car done 335whp, it's very good, but à the track it still run 13.50@100-102, not the good times at 13.00-13.20@108-110 of the beginning!!! We don't know what to do more! A lot of whp on the dyno but not at the track! Do you believe that if we remove the computer for a complete reprogramming will be the key?

BLK02WS6

iTrader: (2)

It has been said numerous times in this thread, but I'll say it one more time: YOU NEED A PROPER TUNE DONE ON THE CAR!!!!! A Hypertech on a heads and cam car is not even close to a proper tune...

SS 98

I agree with you BLK02WS6, we go for a proper tune, but we don't understand why the car has the same 335whp that the beginning but run slower! The dyno operator said all is ok, the tune is ok, but we believe in the same way of you, a proper tune!

gagliano7

The car is probably getting knock which is pulling timing and slowing you down. If you can't bring the car anywhere do a mail order tune with one of the vendors here.

SS 98

It can be a possibility to do that! I'm not a perfect bilingual, but when you say "mail order", it means reprogramming the computer on the web or to ship the computer at a dedicated place to reprogram that with a the complete list of mods on the car?

Russ K

iTrader: (1)

What is the air/fuel ratio at wide open throttle? I've seen a lot of bad mass airflow sensors that caused very lean air/fuel ratios.

Also do a compression test to verify that you didn't bend a valve when the pushrod got bent.

Russ Kemp

SS 98

Thanks Russ K! A/F is 13.0:1 at WOT and MAF is new, an OEM GM one! Compression can be a good test, but the engine run very well just like the whp prove it at 335!