Hi guys....
Is there a thread on this site which lists 1/4 mile results....
A dedicated thread where members can post their results and have a brief description of their setups and attach their time slips....???

for example..... the following details would be good to provide some indication of what power and setup is required for a desired ET.
I know there are HP calculators that can estimate this, but it would be nice to know the actual numbers.

[model/year] [1/4 ET] [1/4 mph] [60' time] [1/8 ET] [1/8 mph] [rwhp] [weight] [tyre type] [timeslip]

I have ordered a 383 / 460hp small block for my 68 vert which has a TH400 trans, 3.36 diff. I'm hoping it will be sufficient to get me into the 12's.

Has anyone actually weighed their vette on a weigh bridge to determine the true mass? 3250lb is the spec I've read, but I'm sure that with all the power accessories (A/C, PS, PB and PW) it is more.

I'd be really pleased to see some actual timeslips of guys who are running similar powered 383's in a chrome bumper automatic vette.

cheers

tom

 

While there is no official 1/4 thread here on the C3 forum but many have posted there 1/4 or 1/8 results. Do a search and eventually you will see the drag strip threads

Also check out this site http://www.dragtimes.com/ as this is probably a better source for you as it has all the parameters you are requesting.

 

There is one in C4 tech, that has been going for a long time Central Coaster started it and updates it from time to time. Maybe someone could do the same here.

 

Tom, I weighed my 71 Coupe, SB/AC/PS/AUTO and it weighed 3380lbs at our local track. Its completely stock, the only weight reduction was removing the spare tire. Mine was not as light as I thought it would be.

I would think your car with a true 450 crank HP should go bottom 12s if not high 11s with a good converter and suspension setup.

I will be doing a similar build up as you using my TH400 and probably start out with my 3.08 gears and eventually change to 3.55s. I am shooting for mid-high 11s and look stock with AC.

 

1st setup:

383/465 HP (9.8:1 compression)+ 5 speed TKO transmission:

11.67@119.79 mph

2nd setup:

406/580+ HP (11.61 : 1 compression) + 200R4 transmission

11.05 @ 120.89 mph

3rd setuo:

406/640+ HP (12.8: 1 compression)

10.35 @ 127.59 mph (on engine in 60 degree weather)
10.07 @ 131.82 mph (with 100 shot of nitrous in 80 degree weather)



Next setup (coming soon)

434 small block w/ 23 degree heads, 13.9 : 1 compression, 250+ shot of nitrous, powerglide

Expected ET's.. High 8's to low 9's


As for your setup.. I'd expect mid 12's with a 3500+ stall converter and upper 12's with a stall speed less than 3000. If you'd go with a TH350 or TH200R4 and take some weight off the car, you could hit 11's with the right converter. The TH400 eats up way too many HP to run better than mid 12's with 460 crank HP... Parasitic loss is a lot lower on TH350 or TH200R4

 

See my signature for info.

 

Thanks for the reply guys...

I have been searching through the forums and found a few results, and have also been manipulating numbers with several HP calculators which are available.

The calculators indicate I should get high 11's, but I think it's optimistic.
GrandSportC3, I think you're correct... the driveline in these classics is very inefficient.....
Is the TH200R4 easy to install?
I was considering the TH700R4 as a 4sp OD box.
What are your thoughts on the TH700R4?

AJ, you and I are on the same wavelength.... I like the sleeper look too. I've ordered my crate engine and requested the alloy heads, manifold and block all painted chev orange to maintain a "stock" appearance.
If I can consistently get into the 12's I'll be very happy.
If I get low 12's, I'll be over the moon.


What is a realistic rear wheel power output from the advertised power outputs of crate engine suppliers...... I gather they advertise power output with NO accessories. The motor I have ordered is from the engine factory.... The 460HP 383 http://www.enginefactory.com/460stroker.htm

Has anyone got one of these engines fitted?
The vette is a cruiser.... club runs through the winery didtricts, street cruises and the occasional club day at the track and strip. I wanted reasonably good torque across a wide band, with good power, and this was suggested.

I was considering engines (better priced) from a few other suppliers too, but living in Australia I was concerened about support if there were any issues.
Engine Factory have an Australian contact to look after customers, and in the end, that was the decider. Good support.

I hope I've made the right decision.
Like I said.... If I can get into the 12's consistently, I'll be happy.

GrandSportC3... Excellent time slip... You've got your car setup very well.... 1.4s 60' That must snap your neck off at the start

the 383 you ran..... excellent time for that power...
Is that 465 rear wheel hp or crank hp?
Do you have details of that engine... maybe a dyno sheet of rear wheel power?

I think I'll need about 330~350 rear wheel horsepower to achieve my target mid 12 1/4 mile time. Motor should arrive late May.

 

C3 Stroker....1969 Corvette Coupe/ 388 Stroker 373 RWHP, 452 RWTQ, 11.62 1/4 mi.
Very nice car and setup.....

You've certainly got that car sorted very very well.

cheers

tom

 

Hey Tom...it sounds like you decided on an engine... We spoke about a 383 from Derbery performance right? I can understand the local support thing.

Great thread as I was wondering the same thing with my 383. By the looks of the respose I may just see low 11"s with an extra 125 shot of NOS on top of my 475 crank HP. I will be dreaming if this does happen

 

The TH200R4 is a bolt on install.. The only thing that you'll need is the TV cable, carb bracket and TH350 slip yoke. It bolts right in place of a TH400. No modifications required for 77 and earlier Vettes.. I installed mine using the welded 4-speed crossmember.
The 700R4 is a great transmission but has higher parasitic loss than the TH200R4 and requires a different transmission crossmember. It is important to get a "built" version of either tranny to hold up. My 200R4 was built by Art Carr's business California Performance Transmission..

http://www.cpttransmission.com



You should definetely be in the 12's either way but you really need a good converter. I'd also junk the mechanical fan (if you are using one) and go with electric fans. That's good for .1 at the track..


I had a 383/465 HP stroker and the crank HP rating was 465 and the best RWHP was 365 RWHP.. That was with a 5-speed. The TH400 will eat up a lot more.. Expect about 320 - 330 RWHP with the TH400, 345 - 355 RWHP with a 200R4 or TH350 and about 365 - 370 RWHP with a stick shift tranny.

That was on a nitrous launch. I've been in the 1.39 range without nitrous.. My car dead hooks on every launch with the wheels 1 - 1.5 feet off the ground

Here are 2 launch pics: First pic was a 1.39 60' time and the 2nd one was the 1.40 60' time from the timeslip posted:




465 crank HP (gross) and 365 RWHP. The car was about 3200 lbs with driver at that time with a 5-speed (less parasitic loss). I was runnin electric fans and open exhaust to get those times. You will need to run open exhaust too if you want to hit 12's

I'll look up the dyno sheet and post it in a few minutes..

I think that 320 RWHP with a good converter should get you into the 12's..

 

here are the specs and the dyno sheet of the old 383:

4.030 bore, 3.75" stroke
Dart Iron Eagle heads with 215 cc intake runners and 64 cc chambers. Chambers blended and ports matched
Custom Solid flat tapped cam with .525/.545 lift and 238/248 degrees .050 duration
9.8 : 1 compression,93 octane fuel
Edelbrock TM-1 intake, port matched, 1/2 inch spacer
Holley 80528 HP series 750 mech. secondaries carb

Transmission:

Tremec TKO 5-speed

Rear end:

3.70 Auburn posi.

Here's the dyno sheet:



Wanted to add.. The 11.67 @ 119.70 mph with that setup was achieved using Convo Pro lightweight wheels, 28 x 11.5 - 15 ET Street slicks in the rear and 28 x 4.5 - 15 Good Year skinnies in front. I was also power-shifting 2-3 and 3-4 on that run.
My best time on street tires with that setup was 12.49


A fellow forum member bought my old 383 and put it into his 3600 lbs '78. He ran a 200R4 tranny with a street converter and his best run was in the 12.90's on street tires. With a better converter, he would've probably run 12.50 or so.. A good converter can make 5 tenths or more difference!!!

 

He and I had spoken, and we thought that with a good converter, 4.11-gears (he was running 3.36s), and slicks (that-much power, converter & gears would require a serious tire, and he began towing the car to/from the strip, so D.O.T.-legal tires wouldn't be an issue), the car might've gone very low 12s.

 

GS: Are you running an idependent rear suspension on your Vette? Or has a straight axel rear been installed? Nice pics.!

 

I have Tom's setup in the rear (12-bolt Independent Rear Suspension)

 

Thanks all for the feedback.

Sting....
I had a number of concerns in deciding which supplier to use.... and what motor to purchase.
I had concerns whether a 383 would fulfill my desire for a streetable small block with "big block" performance.
More cubes is always a sure way of ensuring adequate power, but I also didn't want the car to be too wild, or too costly to run and maintain. (Tyres ain't cheap )

NOS is a sure way to get additional performance at minimal outlay, but it worries me in regards to stress on the motor..... did you get a forged crank/rods and pistons?


I was also considering a 408 sb from T&L and also the RealStreet 434 from Shafiroff. T&L have some very well priced packages, and Shafiroff have some awesome component packages in their Ultrastreet range.

In the end, the decision was based more on concerns about support and customer service.

And a realisation that about 350 rwhp would be more than enough power for the street.. especially in a 60's classic.


GS... you give me a lot of hope that my motor WILL achieve my objectives. I'll look at the TH200R4 as a better option for an OD trans as you mention they are more efficient... 345 rwhp is a bit better than 322 rwhp

I'm really not sure what to expect when it all comes together.
My vette currently looks and sounds fantastic, but is not quick by today's standards.

My current daily driver is a late model turbocharged inline 6 ute (sports truck).
It weighs in at a porkly 4100lbs, but it's tweaked and has 400 rwhp.
A bit sluggish off the line (due to weight) but it boogeys along very well when it's on boost. I run a 2600 stall converter in it, and it operates very well on the street. Best time is 11.83 @ 119mph using M/T ET Street radials.
The main reason I decided to get a transplant for the vette is because of my ute.
A 14.5s 1/4 was a quick time back in the 70's, but it just doesn't have any street cred these days.

I've never driven a stroker before, and am looking forward to having a bit more torque on tap....
The ute has heaps, but there is a delay between flooring the pedal and getting pushed back into the seat.

I'm hoping that my 383 engine combo I have selected will have better throttle response. (no turbo lag time)

Speaking of throttle response..... the engine I'm getting is fitted and tuned with an Edelbrock 800 cfm #1813 carb.
Holleys are predominantly used in Australia, along with Barry Grant carbs.... Would there be any advantage in swapping the Edelbrock for an alternative carb, given that the primary role for the car is street cruising (city and countryside) My objective is for good reliable spread of torque across the rev range, rather than a peaky high horsepower screamer. Would a 750 cfm DP be a better alernative ???


Thanks to all for info provided...

Now I have to wait patiently for the motor to arrive.....

 

With all other things equal (i.e. torque converter stall speed), the 200R4 will give you probably .2+ better ET bit at least .1 better than a TH400..

 

Yes, he could've been in the low 12's but not without taking some weight off his car. Stock 78's were very heavy..

 

Before I changed to the 825 Demon, I ran the Edelbrock 800 cfm carb. Both will give good throttle response (compared to turbo lag, especially), but the Demon's is quicker....instantaneous. It was worth .2 quicker ET at the strip.

 

I don't have my car finnished yet, but anyone care to take a guess on what it may run in the 1/4

It has a Ram Jet 350 fuel injected engine rated at 350 HP / 400 torque
Keisler TKO 500 transmission
3.70 rear gear

 

I would say 13.20s-13.50s or so if you get a decent launch and hook up. 350crank HP is about 250-260hp to the wheels with a stick and IRS.