Detuning a drag car (sort of)

[benoitthegr8]

I just purchased an 87 Turbo-T, the car is pretty fast for a fat tune and only 15 lbs of boost (still tuned for rebuild break in) The car comes out of the hole hard off the foot break, but the lag sucks to trying to get into it at 25-30 mph... also the car cruises at 65 at like 4000 RPM... I want to make the car more street friendly, first thing I want to address is the cam. I'm thinking the cam is a bit too big for the set up, the thing lopes and sounds like a V8 at idle. I'm also looking to go to a PTC lock up convertor. Besides that the roller lifters in this thing are loud, like a damn type wrtier... especially when sitting behind the steering wheel, hell it sounds louder when driving then when outside the car listening to it idle...1700 miles on the rebuild...build as follows... 6152 Jounal bearing turbo, Champion ported stock iron heads and intake, 218/218 Comp roller cam, Roller rockers T&D (I think), SMC Alky, stock MAF, 65 lb mototrons, In tank double pumper, Stretch SLIC, 3" THDP, 2 1/2" ATR duals, CPT built TH2004R, CPT 9" 3200-3400 stall non lock conv... tell me what you guys think and if I'm in the correct direction? thanks...

BT

 

[GNeric]

I have a 70 series turbo, 224/224 roller, GN1 heads, 83# injectors, MaxEffort Mafless, Front mount, 3" THDP, homebuilt 200-4R-Vigilante 3200. Mine idles at an almost stock sounding idle. Runs great on the low end. 25mpg on the highway and just found my 4800rpm rich problem. I was told my cam would be too big for the street but it ROCKS at all throttle positions.

 

[wickedtt]

I just purchased an 87 Turbo-T, the car is pretty fast for a fat tune and only 15 lbs of boost (still tuned for rebuild break in) The car comes out of the hole hard off the foot break, but the lag sucks to trying to get into it at 25-30 mph... also the car cruises at 65 at like 4000 RPM... I want to make the car more street friendly, first thing I want to address is the cam. I'm thinking the cam is a bit too big for the set up, the thing lopes and sounds like a V8 at idle. I'm also looking to go to a PTC lock up convertor. Besides that the roller lifters in this thing are loud, like a damn type wrtier... especially when sitting behind the steering wheel, hell it sounds louder when driving then when outside the car listening to it idle...1700 miles on the rebuild...build as follows... 6152 Jounal bearing turbo, Champion ported stock iron heads and intake, 218/218 Comp roller cam, Roller rockers T&D (I think), SMC Alky, stock MAF, 65 lb mototrons, In tank double pumper, Stretch SLIC, 3" THDP, 2 1/2" ATR duals, CPT built TH2004R, CPT 9" 3200-3400 stall non lock conv... tell me what you guys think and if I'm in the correct direction? thanks...

BT

4000 RPM at 65 sounds like you don't have a 4th gear!! That set up also shouldn't have so much lag, something isn't right..

 

[GNTIM]

Sounds like you have mechanical problems that you need to fix first. That car should be very streetable. The roller cam and rockers will be a little noisy but it sounds like they are adjusted more on the loose side for performance. You can adjust them tighter to kill some of the noise, like 3/4 turn after zero lash.

 

[mygn276]

Sounds as tho your gear is to steep than the 3.42 stock gear . I run at around 2500 rpm at 65 mph with my 3.23 with 400 trans. I thought the 218 218 cam was a flat tappet. Tighten the converter and gear and you should be good to go.

 

[kenny]

Something is way off.

 

[benoitthegr8]

I've got an extreme automatics stage 1 tranny with a PTC lock up, I think I'm going to put that trans in and see if it helps with any of the streetability... guess I'll go from there

 

[turbonatr]

Before going through all that trouble, why not just pop the diff cover off and see what gears are in it?

Being too fat will hurt spool time.

 

[Phoneguy]

Art Carr trannys don't like to shift into 4th until about 65 mph. Let off of the gas pedal a little and back on it again to see if it will shift into 4th gear. Mine does this as well.
Need more info on your tune. That combo should not have any lag. My GT-K 850 does not lag. Sounds like you are way too rich down low.

Bryan

 

[benoitthegr8]

OK, so I wanted to take the car out and drive it and get some readings off the scanmaster... the car starts up and idles fine, then I realize that my factory tach is reading about 750 (3 bars) higher then the scanmaster, I now feel like an idiot for not checking this in the first place... sounds like my tranny was running about 3250 rpm @ 60-65 mph, not too far off. I get the car warmed up pull out of the drive was and get about 100 ft down the street and realize the engine is sputtering badly as I gas it... WTF.... I couldn't get any scanmaster readings at WOT because I was afraid it would die on me on the road. The car did not run like this last night... I drove it 260 miles from GA to NC, now I feel lucky I made it home. Anyway, I went strait back to the house and parked it. It feels like under throttle the engine is getting fuel or something... at idle the scam master readings look normal except the BLM's are jumping around between 122-140??? no MAL codes eithier....

 

[turbonatr]

Last time my car sputtered badly under boost it was due to a bad alternator. Installed a new alternator and it went right back to frying the tires from a 40mph roll. It's something that's quick and easy to check. Put a volt meter on the battery while the car is running.

 

[benoitthegr8]

the car isn't even under boost, this was happening driving through my neighbor hood at 20 mph.

 

[Quick6'n'-K.C.]

Just go back thru the car and do a early spring cleaning. Plugs, wires, cap rotor check the coilpack and replace the fuel filter.

Possible its low on gas or the maf is flakey, Takes time to get used to a new car, they all have their issues you have to sort out.

My blue limited was removing the entire dash assembly with harness to rewire it because the aftermarket gauges were reading weird when the headlights were turned on. That turned into a 2 day project but it was worth it in the long run.
There was so much wrong i took 10 lbs of wiring out because of previous hacker with the alarm... Its all fixed now

BW

 

[Quick6'n'-K.C.]

this and the car isn't even under boost, this was happening driving through my neighbor hood at 20 mph.

I had a car here doing that, the power feed wire to the fuel hanger (hotwire) was not fused and was chafing against the frame. Since it wasnt fused, it started melting the wire, made the car ACT funny.

Go thru the car front to back before you do anything, heck just varify everything that should have been done, IS DONE after you look it over
BW

 

[Audie1]

OK, so I wanted to take the car out and drive it and get some readings off the scanmaster... the car starts up and idles fine, then I realize that my factory tach is reading about 750 (3 bars) higher then the scanmaster, I now feel like an idiot for not checking this in the first place... sounds like my tranny was running about 3250 rpm @ 60-65 mph, not too far off. I get the car warmed up pull out of the drive was and get about 100 ft down the street and realize the engine is sputtering badly as I gas it... WTF.... I couldn't get any scanmaster readings at WOT because I was afraid it would die on me on the road. The car did not run like this last night... I drove it 260 miles from GA to NC, now I feel lucky I made it home. Anyway, I went strait back to the house and parked it. It feels like under throttle the engine is getting fuel or something... at idle the scam master readings look normal except the BLM's are jumping around between 122-140??? no MAL codes eithier....

Possible vacuum leak W/BLM's @ 140. I also agree with GNTIM as far as adjusting your valve train to zero lash then 1/2 to 3/4 of a turn farther should quiet things up a bit. It will probably run better (if they are too loose)......Good Luck

 

[benoitthegr8]

Wouldn't a bad maf trip the MAL 33-34?

 

[turbojd]

When I ran the stock maf sensor I had one code a 34 that was bad and I had another with the car starting to act up and sputter and it didn't code in this case, maybe I caught it as it was just starting to go and it didn't code? anyways I replaced it with the translator and 3" LT1 sensor, no problems since!

 

[benoitthegr8]

I was planning on replacing the stock MAF with a LS1 at some point anyway, I'm lucky the car made it back from GA before it took a $hit on me, oh well... I've got an LS1 w/translator on the other car, I guess I need to send my chip back for a reburn before I do anything.

 

[turbojd]

You don't need to reburn the chip if your just putting a translator and a LS1 maf on the car, that is of course unless you have more upgrades in mind.

 

[benoitthegr8]

Thats for a TT chip? I thought I rememered having to tell them the type of MAF... maybe that was for the Commander chip I had burnt... Anyway some of the other issues; When I spoke to the guy who had worked on the car he had said the Converter was stalled at 3400... a bit much for a 6152. The plan is to check the MAF, check plug, wires, all the vac lines, change the oil and filter, put my xtreme automatics trans and PTC converter in the car and see how it feels. let me know if I'm missing anything.