Proracing

I recently had a 421 stroker motor installed in my 07 C6 A6 and just want some opinions of the HP it made, I feel it should of made more but maybe I'm wrong.

It's a TSP 6.0L 421 stroker iron block with Ls3 stage 3 heads ported and polished, 11.5:1 pistons, comp cam duration 231 247 lift .617 .624 113 lsa, Fast intake manifold, 60# injectors, 25% under drive pulley, SLP 1"3/4 LT no cats and B&B bullets, Yank 3600 stall. HP tuned on a mustang dyno.

HP is 469
TQ is 483

I was under the assumption it would of made 500 HP to the wheels.

Any comments would greatly be appreciated.

mjb929rr

I think that seems low, my car made 471rwhp with a cam and headers. 08 ls3. I wonder if that cam is big enough for that many cubes?

BornSUPERCHARGED

Small technicality, a 421ci stroker is not 6.0L, it's 6.9L. With your 6L80E and high stall, you're going to see lower numbers to the wheels than if you had a manual. Given that its a mustang dyno, I think your numbers sound about right, perhaps a little low. Just remember that at the end of the day it's just numbers, and the dyno is meant for tuning. If you want to hit 500 just to have the printed out dyno sheet, run some race fuel . All things considered, I'd be pretty happy with those results - but it is an extra hundred pounds up front that you've gotta move since its an iron block.

What intake are you using?

Proracing

Just curious if that is dyno jet numbers or mustang dyno. Mine made 520 on a dyno jet. Also I was told to add about 50 more rwhp do to the torque converter,which would be 570 total. Something about the dyno doesn't accurately read the power do to the 3600 stall.

Proracing

That's correct it's a 6.9L, and also extra weight do to the block. #'s are just #'s but I was under the impression it would of made 500 no problem.

pit-man

I would be very happy with those numbers, having an Auto and being on a Mustang Dyno. To compare, I have a 402 from TS with a very mild cam, 3600 stall and only pulled 445/413 tq on a Dyno Jet..this motor is in a heavy Silverado. It runs 11.14 et @ 120mph.

You have more tq than hp too. That will be a very fast vette you are driving. A Ten second screamer with good tires and gear

FloydSummerOf68

I guess I'm the first one in this thread that would be REALLY dissapointed with those numbers.

Hopefully the dyno just reads low and it'll go run mid-low 10s and 130mph all day long. If it doesn't then you spent a lot of money on a turd.

FloydSummerOf68

Wait...so you have dynod it on a dynojet as well and it made 40 more torque?

JUIC3D

Dyno shmyno, it's an auto with a stall, and a big nasty motor. Go run at the track and post up your 10 sec slips.

Jack Package

I concur with most of the opinions on here...Mustang dyno (-20 to 35hp) and loose converter (-15 to 30hp) is what makes it read low, but go to the track with a decent tire and see what it does. If it runs the number, then all else is immaterial.

Proracing

Thanks for all the posts guys, I spoke with my tuner today and he said exactly what most of you guys said. It's just the way the dyno reads it with the auto and stall. He said it will run mid 10's all day with a good slick. Now I have to go buy tires and run it! : )

pmj341

I got a Katech 427 stroker short block and installed a set of Trick Flow 225's and a ported 92mm Fast with 12.3 comp 8.7 dcr, Cam is a 236/240 613/598 i think, my RWHP is over 600.
Pump gas and I just did a 1800 mile trip and got 22 mpg at 80 mph.
Yours seems low for sure.

099blancoss

What stall is in it, those are very low numbers

SBCGENII

Did you ever run it at the track? I wouldn't be to worried about the dyno #s. How do you like the motor so far?

Proracing

I have not run it at the track yet. But I have run several of my friends that have superchargers and one guy that has a Susuki GSXR 1000 and I've pulled on all of them!! It's exactly what my tuner said, don't pay attention to the dyno numbers, it's just a tool to tune your car. He said my car is a low 10 second car and I now believe him. Lol And I a solution love the motor!! No issues whatsoever and it has tons of power and torque.

jon6.0

Definitelty let us know how it mph's at the track. I'm not a fan of that huge split on the cam. Looks like Comp LSL lobes. Any advance ground into the cam?

monsstrvette

:cheers Hi bud i think your LTs are too small you need 1/78.

monsstrvette

Steve@RSD

You built a big stroker, strokers are torque makers. You cannot compare cubic inches here, you have to realized a strroker engine creates a lot of torque. Torque is acceleration. with that stall you are gonna runs some great low Et's. Get sticky slicks, air them down, heat them up and let'r fly!.
PS, you may also be dissapointed in your MPH, don't. ET's are the name of the game!
Have fun with that stump puller....

SlickShoes

OP, did you get this thing to the track yet?




Have a cookie. Your setup is in no way whatsoever like the OP's, and bares no resemblance to his build. Your numbers are irrelevant. But good job though.