I just finished putting it together and getting the exhaust done. It is running on the stock programming with an AFPR to supply the fuel it now needs. It is MUCH faster than it was prior to all this. I know the RPM range is a lot higher than it was before. It starts pulling HARD at 3500 and pulls hard to 6500 with my stock ported (siamesed 2.5") TPI manifold. Considering this is a SD setup, I really expected it to need programming to even be drivable but it seems very happy, has not thrown any codes, doesn't ping, and runs great. I am sure programming would ring out a few more hp though. Hunting for stock LS1s to surprise now

 

What do you expect her to run in the 1/4? Any rwhp/tq estimates? It's great to hear you're pulling over 6k, I hope mine can when I'm done. How do you like the hotcam? Are you using 1.5 or 1.6 rockers? Do you like them for streetability?

 

So how long do you expect that tranny to last lol? I've planned a Hotcam, HSR, and 180cc heads, but I've realized that my tranny will not take the abuse for long, so I have to do that first

Also, get ready for everybody to come tell you that what you're doing is WRONG and you need to tune the chip, baby! I think you know that already, though. Good to know that you can throw it in there, boost the FP, and it'll run well, because I've got a 92Z with speed density as well. I intend to tune mine too, but I'm going to have to learn it at the same time, so it's gonna have to be able to run while not optimally tuned.

Glad you like the HC, can't wait to get mine!

 

I'm running stock rockers (1.5s), which works out to .492" lift. I am pretty sure it'll go high 12s as is. I am guessing around 290-300rwhp, but thats a guess. I drilled two .125" dia. holes in the throttle plates to get it to idle good, and it does. I am also running 10.2 to 1 on compression after milling the heads and I'm running a steel shim gasket to get the quinch optimal (.04"). It doesn't ping and I'm running 91 octane in it. I think I am going to go to the track this weekend if the weather permits.
My tranny is STOUT. It barks the drag radials hitting 3rd at the strip, so I think it'll hold up to it. I'll find out
Later,
Charlie

 

What tranny are you running? Do you drive on the street much; and if so how's the mileage?

 

Nice numbers, congrats Could you post some more info about your intake mod?

 

I'm running a 700r4 in it, but it is built up (extra clutches, HD sprags etc.). I also have 3.73s so that helps the tranny a bunch.

The intake was gasket matched to a felpro 1205, hogged out as much as possible(a bunch), and siamesed 2.5" from the face where the runners bolt up. They were smoothed out and the edge of the dividing wall was radiused to the floor and ceiling of the ports. The injector boss lip was cut out and smoothed to match the gasket. The roof where the air turns into the head was raised as much as possible and the transition smoothed as much as possible.

 

Yep I drive it daily but I haven't been in milage mode yet . I'll let you know though.

Is Thunder Valley open this weekend? If it is thats where I'll go.

Later,
Charlie

 

You're around here? That's cool.

I think TVR is closed for the season, though. I think the last TT session was two weeks ago, and they don't open again til Feb.

 

Cool! My hotcam motor is still on a stand waiting for a SDPC manifold. How much vacuum you have at idle?

 

I get 14" of Vac. at idle with a hot cam and a BG 650 DP. I got about 19" with the standard LT4 cam. I love the hot cam with the carb and I bet the TPI will help out the small loss of low end. I am in the process of a ZZ4 cam and head swap on my TPI 305 convertible now.


Brian Felts

 

I really don't know how much it has at idle. I haven't looked at it. I know it has good brakes still though. I bet the SDPC base will work pretty good, especially if you siamese it. I know the Vortech heads will work great with the 10* split to the exhaust on the hotcam.

I'm actually from just South of Wichita, KS but I really like the track down there. Our track sucks bad. I think they spray the staging lanes with slick 60. I can get to thunder in a couple hours and it is worth it. You are lucky to have such a well managed/maintained strip near you.

Later,
Charlie

 

Yeah, it's seriously like 5 miles from my apartment in Norman. Very nice.

 

what is your new fuel pressure setting. Also did you try to run it before drilling holes in the throttleplates?

also how is the lope

 

Can guarantee u that anywhere below 3k rpm your ecm is just puking fuel into the motor, and im meaning as in enuff to wash the walls down and eventually trash your rings. Get it on a scanner and see what it is doing.............

U didnt need to drill holes in anything to make it idle right either...realistically its all in the chip :-)

But honestly u need to get it tuned and sorted out or its not gonna last a real long time... u hit the prom board here and there is tons fo info on getting started.

Just for an example way back when when i first did my combo in my Formula and i was running the stock 22# inj, i removed literally 30% of fuel at idle compared to what was the factory level and 20 or so almost all the way to 3k(and where i didnt pull 20% it was 10%)

Im not preaching, im just giving u a friendly warning to help u avoid some trouble
LAter
Jeremy
Mine idles at 650-700rpm hot gets 17/18 mpg mixed/town and 22-23 on the highway

 

I'm running 60psi at WOT.
I tried running it without the holes in the throttle plates and it wouldn't find the idle. It would stumble and die every time. It idles nice now, and sounds nice and mean

 

60PSI sounds like waay too much. So does 6500 RPMs. When you take it to the track I hope you will at least try a few runs at lower shift points (6000 & 5500 RPMs) just to compare.

 

Larry

If you are running a vortec in Texas? How are you going to over come the EGR problem?


Texas is going to the same smog regs as california. I know there are ways to do it. I was just wondering how you are going to do it?

 

Thanks for the info. I know it needs tuned and you are very correct in everything you have posted.
Thanks,
Charlie

 

Roads88

The SDPC vortec tpi manifold uses an egr kit that feeds off the header. Inspectors here do a visual but don't check part numbers. I think the hotcam has enough overlap for self egr so my egr valve will be disabled but there to pass a visual. VEMaster works great for idle to 3000 rpm fuel tuning! And it's so easy to use.

 

Good luck at the track! I'll take it your wife's z28 is OBDII so that scanner won't work? Whats your FP at idle with the vacume disonnected?

Did you try unscrewing the Idle control screw a turn or so? Mine was dying on me about a month ago when it cooled down. When i scanned it I noticed the IAC was out to 150 or so steps, maxing itself out. A quick adjustment and it doesn't give me any more trouble.

I'm not sure if I'm glad or pissed off that my car is running fairly in tune with very little tweaking (MAF system) but I never thought an SD system would even need as much tuning as yours 3.8transam, how big was your cam? Now I've spent close to $300 on tuning equip and all I've really used it for is to raise the idle a touch and give it a little more fuel at WOT. Hopefully the LT1 intake and some new 30lb injectors will wake the car up a little more when i get them on in a week or two.

 

Ryan,

I am pretty sure my car is running pretty close to it's potential at WOT, but since it is SD it uses the MAP to vary fuel rate based on the stock fuel curve and since I have less vacuum (Hotcam) it acts as if I'm at part throttle and dumps fuel in. I really need to burn a chip or two to get my part throttle mixture in check. I suppose I'll be buying my burning equipment pretty soon.

 

Im running a LT4 hotcam , i dont want it ok i want it right like jump in on 30 below day and drive away right (getting close)....MAF inherently compensates better for it due to the fact that it is a MAF system but to truly make it right on either setup u will need to do a fair amount of tinkering

LAter
Jeremy

 

Larry

Ok, sounds good


Thanks

 

Thats what I was thinking, I'm guessing its probably leaning out on top also, as the VE of a stock engine is horrible at over 6000 rpm.

MAF requires less tuning, but I'm beginning to agree with others that its harder to tune overall. I finally got a pretty good understanding of the 87 to 88 tuning and now with the LT1 intake I have no cold start injector so I have to run a modified ARAP bin. From what I'm seeing the 89 ARAP type bin has many different parameters but doesn't seem as "tuneable" at first glance.

Charlie whats your fuel pressure at idle with the vacume removed? 60 PSI seems plenty high for a stock fuel pump. I talked to a friend with a 68 RS, he may be interested in the headers. Thats a great deal you have those supercomps!

 

I don't know what it is at idle. I borrowed the gage and didn't check it at idle, just with the fuel pump jumpered with the engine off. I was running it maxed out, but have taken some back out since then. I need to get a gage hooked up again.

I would hate to give up that polished TPI intake if I were you. Have you considered porting it? I am really surprised how mine runs with it siamesed.

Later,
Charlie

 

I'm thinking about sticking it on another car, maybe the caprice but I'll see. The biggest thing for me right now is to recoup some of my money spent on the lt1 intake and for next semester. I'd try porting the base extensively but I know that the 406 will need a lot more air than that. The plan is to get as much work out of the way so the car will be down as little as possible and doesn't get made into the never ending project car. If I can get the intake and fuel pump changed, then all I'll have to do is swap long blocks, throw in a 9 1/2" TC and figure how to wire a 70's block for TPI, which hopefully won't take more than a weekend.

 

I had it dynoed today and it went 288rwhp, 351rwtq