Hi, I have a 1985 Corvette. I'm just wondering how much horsepower you guys think this stuff will add, and also, what my 1/4 mile time will be. Thanks!

- TPIS Miniram Intake Manifold
- TPIS 58MM Throttle Body
- TPIS Headers
- ZZ9 Camshaft
- Adjustable FPR @ 60 PSI
- 3.73:1 gears

Thanks a lot! Looking forward to responses!

 

Custom tune required
Do a search , many MR build threads on here to extract info from
like
http://forums.corvetteforum.com/1580365943-post6.html

Best bang for $$ TPI mod going

not required on a 350


Why?

 

custom tune the way to go.
youll read about others never tuning thinking cranking tons of FP instead will do it, not.

 

The headers will add about 15 HP. The 85 responds well to exhaust modifications. Mini-ram should add 5-10. The problem you will have is it looks like you are staying with the stock cast iron heads on the 85. These will strangle your potential gains. The cam will help....but the 85 heads suck....your throwing good money out the window to yield minor gains because of the bottle neck created by the heads.

58mm TB not needed. The stock 48mm will support up to 400HP. Throwing money at something not needed.

The AFPR will not help if you crank it up to 60 psi. This engine should run fine at about 39-42 PSI.

You will without a doubt need a custom tune.

 

Add to list:
-Good set of heads
-True dual exhaust
-Tune

Remove from list:
-58mm TB

You should be very happy with your set up.

 

Get the full TPIS exhaust.......ceramic coated headers and their full exhaust, front y-pipe, big center pipe with hi-flow cat, then big year y-pipe..........they know the 85 set up..........

but yes, the stock heads suck..get the AFR/TPIS heads, but they will cost a little bit.......and I agree the 58 mm TB is too much; don't need that.

 

I was following my instructors setup, where he was following a recipe on TPIS. So he has a guy in Ohio tuning him off of 60 psi which is why I included it here.

So how much horsepower should I end up with total if I have around 230ish now?

And also what do you think my 1/4 mile time would be?

 

And also I should add there is no way I can afford those heads.

 

Since it doesn't sound like you will be freshening up the bottom end and raising the compression any I would be looking for around 300 bhp out of it. It will all depend upon the little things but without over cam'ing it you will have a hard time getting air into it. Just my .02 and I haven't played with stock iron heads for a long long, time.

 

Should be mid to low 13s, depending on air. Before you start, find out where to get a chip burned. Not just anybody will do an 85. Chip is sort of obsolete.

 

Some good info here on Vader86's site:
http://temp.corvetteforum.net/c4/vader86/

 

Go with headers and a full exhaust to start. I picked up 25 peak hp and + 40 hp above 4600 rpm.

The miniram is great but I would be concerned about the higher rpms needed on the stock bottom end. Assuming it's a high mile '85??

Skip the TB.

,

 

You will need heads. Should be low 12's or high 11's

 

Aftermarket heads are expensive but will deliver lots of power. Even the later 113 heads from later L98 motors will be a help. Talk with a couple of area engine builders about port matching and having a good valve job. Consider using roller rockers with a 1.6 ratio.

With the headers, definitely go with a true 2-1/2" dual exhaust and add an X-pipe. Use mufflers that will flow well. I have a pair of DynoMax race mufflers on my '87 (# 17218) and they are quiet on the street but are fairly loud at WOT (95dB). IMHO, Flomasters suck; they have horrible interior resonance.

Also with headers, you will probably want to swap out the factory starter with a Hitachi-style mini-starter. The stock starter will be a royal PITA to get back in place with headers. BTDT!

One thing you didn't mention is the trans type; C4's had two differential setups. The auto trans cars got a Dana 36 and the manual trans cars got a Dana 44. The Dana 44 is much stronger and is a bolt-in. If you are looking at drag racing for your setup and will be running drag slicks, the D36 will simply not last, especially if it's original to the car and the car has high mileage. If the car has the 4+3, think about a good clutch package.

And as mentioned, a custom chip will be needed with serious mods. Look in the C4 Scan and Tune section for good information regarding the early ECM and chips. Don't bother with something like the HyperChip or similar chips; they won't do anything for what you are considering.

 

What Would It Be Without Heads? Or Even P&P?

 

50 mebbe

 

Optimistic at best

 

Those heads arent worth porting just put the other stuff on and save for a good set

You DO NOT NEED 60 psi!!!!

 

Probably gain 50hp and lose 30lb/ft torque. Your power is going to be 4000 plus rpm. Ask yourself, how often do I stay above 4000 rpm? If you live above 4000rpm a majority of the time, make the switch. If not, may want to look into modifying the stock TPI with larger runners, ported plenum, and high flow base.

 

How about vortec heads? Would they be a good choice with these items? Will the mini ram fit? Will i need to choose a different cam? How much power should i expect with all that stuff and the vortec heads? And will the headers fit?