ok this is my first post here and i am looking to get some info about my car. i have an 91 t/a with the l98 and 700r4. i have an hsr intake with the adjustable regulator set at about 47 psi, msd 6al box, no cats, catback, and a comp cams XR282HR-10 cam, the specs are 230 236 duration, .510 .520 lift i know it is a little big for my car, all the free mods, set at 10 degrees advance without computer. well i am still running low 14s. from what i have been reading it should be running a little lower than these times. i am getting longtubes and a tune soon, but at least shouldn't it be in the 13s before that stuff? also since i installed comp springs 986-16 i had to shave the umbrella exhaust vavle seals down a little to fit and now it is smoking a little. is this the reason? i read somewhere that somebody put intake seals on the exhaust side? is this ok and would it help with my smoking? just trying to get my car running good and any help would be helpful. thanks

 

Welcome to TGO. First, are the springs recommended for that cam by Comp? You now have oil getting pass the seals, if you tore them up a little. Also you have to have the spring set up, so you have the correct installed height, to get the correct seat pressure. And, always check for coil bind. Depending on your cylinder heads, you might need the guides cut down a little. Second, what is your MPH? ET, depends on traction, as MPH, will show the power. How much does your car weigh? What are the 60' times? Just not hooking the car up, can kill your ET, but if the engine is making power, it will pull through at the big end, netting some MPH.

 

Yes the springs i installed where the ones recommened by comp. well i put new seals on but the exhaust umbrella seals had some interference with the inner spring so i shortened those seals a little. also got new intake and got the little o-ring one also. so if i didn't have the springs set up correctly would that affect perfomance? they have an installed height of 1.75". had to have the spring pockets machined for the larger spring. i checked for coil bind and i did not have any of that. i also installed a set of arp rocker arm studs. i think that i remember reading somewhere about having to use guideplates with the new studs? true? yea i went and talked to a local speed shop around here right after i got the car back together and they told me that the machine shop should have cut the guides for the new kind of seal but they didn't. my mph was 101 in the 1/4 . my car is stock weight and i'm pretty sure my 60' time was 2.1. i didn't get good traction at all becuase of my crappy street tires. i still have the stock heads for a little while longer. almost have enough for some new ones. just trying to decide which ones. i was looking at the brodix aluminum IK200s and the Dart iron eagle cast iron heads. wondering if anyone has had any experience from either of these. my goal is to just get into the 12s without spray.

 

Yes, You need heads. Brodix, Trick Flow, AFR, are all good heads. I would not go any larger than a 190 intake runner. Also, you can get a smaller chamber, to get the C/R up to 11.1. Should run fine with aluminum heads on pump gas. You mentioned longtube headers. What are you currently running for exhaust? Are you sure your smoke is from oil, and not an overly rich condition?

I would get the heads, step up to a set of L/T headers, add a higher stall converter, and tune it. Pretty much every thing you had planned in your post. What gears are you running out back?

Forgot to ask...what size injectors?

 

why should i not go larger than 190 intake runner? 11:1 compression is still ok for pump gas? well at the moment i am just running the stock manifolds with 3" catback with a flow and no cats. well i am pretty sure the smoke is from oil since it usually occurs more often after startup and at idle. maybe not? i am running the 3.23 rear gears. so i was reading that some people have ls1 aluminum driveshafts. are these the stock ones with the stock length? any improvements performance wise? well for the injectors i have the stock ones don't know the flow rate. what is it? i was also reading about people that were running ls1 injectors too? improvement?

 

A smaller intake runner will do a good job at effectively fiiling the cylinder in the RPM range you will be in most of the time. Really large runners, like 200+, would be great, if you were to spend most of your time at higher engine speeds. I would not worry about the driveshaft now, you have other problems to address. Basically, you have a 350, (right?), and a large cam, a HSR intake, stock exhaust manifolds, stock heads, unknown injectors, and no programming. Not mismatched, as you plan on adding the right parts down the road, but, not going to run 12s either, by the way it is now.

If you go with the Brodix IK200s, which are less expensive then some of the others out there, have a 64cc chamber. IMO they are a good head for the price. Now, how certain are you on your C/R? These heads require 9.5 to 10.5 min. Add a set of #24 injectors, a set of headers, and you will need a tune, especially with that cam, and a larger injector.

You will either have to get into DIY prom, (here on the TGO boards), or have someone tune it for you. With that cam your VE tables will be way off, as cylinder filling at low RPMs with that cam will be poor. You will also have to re work the spark tables as well. Dont get trapped into the "bigger is better theory" with EFI. It all depends on what you want to do with the car.

You just gotta get a plan, and dont stray from it. As you can see, a few parts might, or might not make you fast. Its the total package, that has to be addressed.

 

ok i see the deal on the intake runner sizing. that is correct with the 350, large cam, HSR, and mostly stock everything else for the time being.

so those brodix heads would be an ok choice even with the 200cc intake? they are aluminum and i think that i read somewhere that you can run a little higher compression with aluminum heads?

i live here in tulsa oklahoma about 15 minutes away from ed wright and Fast chips and i will probably just go over to his shop and have him dyno tune it for $350. i have heard lots of good things about him/FAST. with the new cam are you suppose to bump up the timing?

right now i am just guessing that my big bottleneck is the heads? manifolds? injectors? tune?
Thanks

 

You hit the nail right on the head!

 

If you're going to keep the heads you've got on there for a while, you need to have a little more work done to the guides and seals. I had my heads set up to run a ZZ4 cam (.474 int. .510 ex.), and they did have to machine the guides down a bit for retainer to guide clearance. I was also told that umbrella seals are a PITA to run with a high lift cam and performance springs due to the problem of interference with the inner damper springs. You should either have the guides machined for teflon seals, or do what I did and run the polyacrylate positive type valve seals. The unfortunate thing is that you'll have to pull the heads back off and take them to a machine shop to have the additional work done. You might want to find a better machine shop that deals more with racing engines. You need to tell whoever's doing the machine work what your cam specs are so that they can get them set up properly. Good luck!

 

And while they are off....a little porting would not hurt either, until you get the new heads.