fast.asleep

65Z01

Don't feel so bad about 250rwhp which, through an A4, translates to ~300chp.

gerardvg

Hi

How old is the fuel pump and fuel filter?
I would start looking at replacing the fuel filter, standard the fuel pressure should be 40psi.
The TPI loves 50 to 60 psi fuel pressure, not sure on the camshaft.
The car should run good, I got my 85 from std mid 14 sec quarters to 13.2 sec quarter mile with minor works using standard cam and heads. Went to the blower after that..
Cold air intake long tube headers a tune up, cut air filter lid and adjustable fuel pressure regulator..
That is with street tires, so you should be able to get into mid twelve second quarters with what you have.

Try to no go overboard with a hot cam with TPI runners, go to a mini ram or super ram setup.
The std TPI runs out of breath at low rpm, you want to have a torque monster to accelerate from the line.
From idle to mid 5k rpm, anything else you are sacrificing torque and off the line launch.
That first gear is great to give you a launch, with a blower its all about torque so very mild cam suits best.

With all my mods the car ran good, easy start hot or cold.
Look into new 30lb injectors, and standard fuel limiting removal.
Check with fuel injector connection (FIC), they can help sort out your C4 -- make her fly.
https://fuelinjectorconnection.com/
Cheers

fast.asleep

gerardvg

Hi
Yeah look at replacing the fuel pump fuel filter and 30lb injectors, the standard fuel injectors can struggle with higher fuel pressure.
plus look at the FIC fuel injector tests, how poorly some flow just dribble a best.

856SPEED

ddahlgren

New pump and injectors would not hurt anything. The a/f ratio looks reasonable but just the average of 1 bank so really don't know much beyond that. Ignition timing would be good to know if left stock or changed. Personally would have used more cylinder head and cam. over 30 year old injectors kind of silly to keep too.

vader86

Based on what youre saying, its only the injectors that seem like they could be going off if theres actually something 'wrong' with it at all. It may just be out of breath due to the intake.

856SPEED

fast.asleep

Ok thnx. Since a blower is in the future should I swap to a mini ram or put that money towards the bottom end?

vader86

Depends how much boost you want to feed it. I considered a blower at some point and would've had the engine built for that compression and a fair amount of boost, I wouldn't run much boost on the stock bottom end.

fast.asleep

856SPEED

There might be some out there on ebay or wherever. Or you can call TPIS and ask them if they have a deal they can work out for you. You need the fuel rail system they have as well. I originally did not believe the TPI intake system would be so restrictive when I did my build many moons ago. But I quickly found out why the mini ram was so expensive after looking at my dyno test and taking it to the street and track and going up the competition. It came out of the hole like a scared rabbit, but the party ended at about 60mph when I was looking at tail lights. The mini ram changed all of that (same cam and heads). Also, looking at your A/F ratio, there is no fuel delivery issues at all. Your A/F ratios are safe at less than 13:1 at WOT. That doesn't tell you it is starved for fuel at all. In fact if they leaned it out to about 13.2:1 at WOT or so, it would put down a little more power and I don't have a clue what kind of timing you are running, another important factor (at WOT). SBC like a lot of timing at WOT. The LS engines actually do not need as much timing due to the efficiencies of the cylinder heads.

Having said all of that, I would not be too upset by your numbers. You have some torque at the tire off the stop light and overall it should be a fun car to drive.

ddahlgren

I would want to see the knock counts if any at WOT as timing might be leaving something on the table. If none I would be tempted to move the timing up until on or two and if a bunch take some out as ECU might be pulling too much out.

KyleF

Testing a TPI all over 4600 RPMs is laughable. What they other guys are telling you about the intake making HP is simple. HP is the ability to make Toque at high RPMs. Your Heads/Cam are designed to make power Higher than the SLP Runners. It's not matched well.

As with anything mods, Data log and ensure health and function before getting too upset. Also, if your Cam... and I didn't look for any details here, is designed for a blower, don't expect it to add a lot NA. It will come alive under boost.

If you want HP a mini Ram or similar will be needed.

383vett

Backwards.

ddahlgren

hp=(torque X RPM)/5252
so hp is the rte you can generate torque.
No torque no hp.
Torque generally falls off 15% between peak torque and peak HP so bigger the torque number and the longer you can hang on to it the more HP.
This engine is only making 7 more HP between peak torque and peak HP it is basically a 245 HP engine and probably only has 245 worth of airflow.
The only chance for a low buck help might be 1.6 or 1.65 rockers to put some area under the curve for more air flow.
With the typical loss of 15 to 20% for rolling resistance trans u-joints tc. On it's best day this is a 380 to 395 ft.lbs and 280 to 300 HP at the flywheel.
This is about what you would expect from the intake and heads.

Tom400CFI

15-20% is very generous. I see numbers closer to 10% on Dynojets.

ddahlgren

fair enough. Most of the stuff I have run on a dynojet are bikes and they get sensitive in how tight you strap them down or tire inflation. Would not have believed it if did not see it more than once on turbo busa's. Usually around peak torque when needs to tied down tighter to get a better bite on the roller. I have run hundreds if not thousands of engines though few on chassis dyno's. Hooking the car or bike up is generally more trouble than what is learned. They do in my experience work well for finding drive response and an ocassional miss that is hard to catch in a data stream though.

bjankuski

recent dyno on ls1 = 593 engine hp. Same engine in car made 492 whp, that was a manual tko 600 trans and ford 9 inch rear on a mustang dyno. 17% drive train loss. I do agree with you that the factory numbers read higher, more like 10% on a manual and 15% auto.