HELP: Best Mods for for daily driven GN.

[1BADGN]

My 87 GN is pretty much all stock except for K&N air filter, exhaust, and a mild chip and a aftermarket Intercooler..

My car has just about 50K miles on it. I want to know what mods I should do next keeping in mind that my future goal is to build the baddest street driven GN with a stage II motor to beat all these new Z06's down here in So. Cali. Until then, however, I want to get the most from my stock block.

Here's what I think I need but I need help from the "experts" out there to help guide me in the right direction. Please add anything to my list that I missed.

1. Bigger turbo, but what's the best to use in this application? approx $$

2. Bigger Injectors, what size? approx $$

3. Fuel pump? Pn? B approx $$

4. Should I upgrade the heads too? approx $$
Should I even consider doing this without freshing the bottom end?

If I do the above mods what do you think my times in the 1/4 mi would be? I just want to beat all the Vette's down here, excluding the new Z06 because they are running low 12's and I doubt I could do that with only these mods.

Thanks in advance for any help.

 

[John Larkin]

Do a thorough tune-up/spring cleaning first!!!!!

If you're gonna build a Stage II anytime in the next two years, then don't buy stock block upgrades too heavily. Great fuel system would be first on the list (double pumper, hot wire, adj regulator); next a compliment of good gauges (fuel, boost/vac, knock, oil, water); next, a good scantool and street chip; next, good street tires; next, a high-boost wastegate actuator and good heavy-duty IC hoses/clamps; next, stock location big-neck stretch intercooler; next, a good 3" downpipe and exhaust; next, trans cooler; next, adjustable upper rear control arms and aftermarket or boxed lowers; finally line lock, 3" rear wheel studs and an extra pair of wheels/slicks for track and a race chip.
If you do things in sorta this order, you should be pretty fast and not have wasted alot of money on non-transferable items. A Stage II engine will likely need a bigger turbo, injectors and transmission that your stock block won't make the best use of if you are going Stage soon.

 

[WIKEDV6]

Get SMC alky kit

 

[blackshoebox]

Originally posted by 1BADGN
My 87 GN is pretty much all stock except for K&N air filter, exhaust, and a mild chip and a aftermarket Intercooler..

My car has just about 50K miles on it. I want to know what mods I should do next keeping in mind that my future goal is to build the baddest street driven GN with a stage II motor to beat all these new Z06's down here in So. Cali. Until then, however, I want to get the most from my stock block.

Here's what I think I need but I need help from the "experts" out there to help guide me in the right direction. Please add anything to my list that I missed.

1. Bigger turbo, but what's the best to use in this application? approx $$

2. Bigger Injectors, what size? approx $$

3. Fuel pump? Pn? B approx $$

4. Should I upgrade the heads too? approx $$
Should I even consider doing this without freshing the bottom end?

If I do the above mods what do you think my times in the 1/4 mi would be? I just want to beat all the Vette's down here, excluding the new Z06 because they are running low 12's and I doubt I could do that with only these mods.

Thanks in advance for any help.

As previously stated, if you plan on building a stage car soon, don't waste to much cash on the stock block build up, but if you want to have a fun, fast street car, with the stock block, I would do:

Turbo- TE-44=750$$
Fuel-009 injectors, 340 walbro fuel pump=500$
Champion Ported Irons with Intake=1300$

With an intercooler, thdp, exhaust, and the right tune, you should be in the 11's. If you wanna go faster, you could run a bigger turbo and high stall converter, and even swap the stock location intercooler, for a FM, then your in the 10's. If you have a true 50k bottom end, that is unabused, if you are on a good tune, and don't detonate, you should be fine. If at all, replace the timing chain with a steel double roller.

If you do your own work, cost is relatively cheap, labor is normally more expensive then parts after its all said and done.

Shoebox

 

[azgn]

you certainly do not need a StageII to beat ZO6's......the mild upgrades suggested (turbo, fuel, exhaust, IC) will do the job just fine....mid 11's without breaking the bank

 

[86brick]

1BADGN, with an upgraded turbo like a TE-44/TA-49, bigger injectors like 009's (42.5lb) or better yet 50's, a Terry Houston or ATR 3" downpipe, and a single 340 walbro fuel pump you should be easily running low 12's - high 11's (possibly a mid 11 with a good 60') @112-115mph with about 20 - 25lbs of boost and a 1.7 60' with some sticky tires (BFG DRs or E/T Drag slicks). You do NOT need to open the motor and have the heads ported/polished to run in the 11's, but it is a good idea to change the valve springs cause if you still have the stockers the car will lose mph. Also, depending on your car the tranny may need to be rebuilt and if your going to rebuild it a 2800 stall lock-up converter would be a good idea IMO and if you run the car with the stock D5 converter make sure you lock it up with a TCC lock up switch cause that simple cheap little mod will get you 2 tenths and 2mph. Unless, you want to run deep in the 10's or faster there is NO need for a Stage II motor and you will be wasting your hard earned $$$$ cause the newer Vette's even the Z06 Vette's aren't that fast and with about $1500 - $3000 in mods you will be handing them their asses and laughing at them for spending $50k to run low 12's - high 11's Also, keep in mind most Vette guys can't drive worth a sh!t as I've seen plenty of times (new Z06 Vette's running 13's)

 

[1BADGN]

Thanks for all you inputs.

I was wanting a Stage II because I thought that was what I would need to compete with the new Z06 but after reading some of you posts I am beginning to reconsider.

My car hasn't been driven that hard meaning it has never been to the strip. Not to say I haven't raced some ricers and Vettes from the stop lights around town.

With the new gas laws they are imposing here in CA the octane rating will be increasing from 91oct to 93 which should allow us to get more boost too.

1. What is the limit of boost before you start running into problems with detonation using 91 oct.

2. What is the max boost before you will blow head gaskets on a stock block?

 

[86brick]

Let me add one of the most important mods I forgot to mention..... get a Scanmatser ASAP cause without this simple Scan Tool you will be lost and will be running your car blind This will help you tune the car for it's best performance and this will help you keep the car from detonating which is by far the most important thing you can do for the life of your motor!!! Also, if you don't already get the basic gauges like Boost, oil, temp, and get an adjustable fuel regulator so you can adjust fuel pressure properly. There are a LOT of little things with these cars that are key to have and in most cases these little mods are more important than the bigger mods. If you haven't already check out www.gnttype.org cause there is a bunch of things to be learned and other than this BB that site is the best!!!

 

[c&cgn]

Baseline the car first. Do the basic mods first but leave the Big 3 alone. (turbo,ic,injectors).

Go to www.gnttype.org first and do the basic recipe stuff first like:

Walbro 340 FP w/hotwire
Adj FPR
Cold air system
aftermarket boost gauge
Scantool of some sort

Get it running at it's peak in stock form and then start the upgrades.

If you can't get the car to run at least high-mid 12's on the stock parts then you have other problems to look at before masking them with upgrades.

 

[86brick]

With 91 or 93 octane pump gas the most boost you'll be able to run safely is 13-15lbs. However, with an SMC alcohol injection kit you could run about 19-22lbs of boost on pump fuel. Really, with these cars though high octane race gas is needed to see the best performance at the track and if you don't like spending some money for race gas you bought the wrong car!!! Like I mentioned the SMC alcohol injection kit will let you run around 20lbs of boost (22lbs at most) safely with no detonation, but anything more than that will require race gas. I would say the most boost you'd want to run on a stock block would be about 25-30lbs, cause after that those head gaskets tend to lift. I know of one guy running around 35 - 40lbs of boost with a stock block and he's been running a stock block like this for about 4 years (he's run a best of 10.03 @134mph), but he's a pro and knows the risks and his car very well!!!

 

[JeffG]

For a mostly street driven car I think alky is hard to beat as one of the best mods for the $.

 

[scottyb]

Put a high-flow cat/test pipe w/ exhaust closer to the top of your list, especially if you still have the 15 year old cork! My close-to-stock car gained solid 5 tenths in the 1/8 with the test pipe instead of the original cat.

 

[TT/Ameasap]

Get a scan tool and know where you are at first, fine tune your motor to run as much boost as you can without Knock. Then add what you think would be the best for your ride!



Like lots of others have said "TUNE FIRST, THEN MOD"
You and your car will be alot happier

 

[UNGN]

The Recipe mods on GNtype.org will put ANY good condition, good running TR into the 11's (enough to handle 95% of the Z06's out there) for about $2000. A stage II build up could cost 5 to 10 times that.

The only caveat is this is with race gas. One of the problems with getting 450HP out of 231 cubic inches at 4500 RPM is that you can't do it running 91 Octane. If you Divide $48K by 48 monthly payments plus interest, you will see you can buy enough race gas to smoke every ZO6 in southern california for the cost of one month's ZO6 payment. Going fast costs money. How fast do you want to go?

 

[86brick]

Listen to UNGN! His car goes very fast on a budget and I agree 100% with everything he stated in his last post If you want your GN to go fast on a budget follow the recipe page on www.gnttype.org and make sure it is in good running condition before you start with the performance mods like UNGN mentioned and those ZO6 Vette's will look great in your rear view mirror

 

[Ken Cunningham]

Don't forget the unglamorous stuff that help stiffen up the car: replace the missing body bushings, put the braces in the rear seat and the front frame. Also an engine tie down so all your torque doesn't twist the motor off its mounts.