Speed Engineering True Duals vs Hawks Sinister 4 inch
#1
Speed Engineering True Duals vs Hawks Sinister 4 inch
Good evening ladies and gentlemen....i need your experiences and opinions. Lloyd Elliot is porting my heads and Stealth Ram and has already recommended a cam for me. IIRC he said a 231/239 cam and around .580/.601 lift. It looks similar to the Lunati Voodoo cam which a member has on here and one a 355 M6 guy has on ls1tech. Needless to say I am excited because jumping from a 224/230 cam to this cam will put a smile on my face.
I am junking the hedmen 1 5/8 longtubes and going with Dyno Don shorties with dual 2.5 inch cut outs.
I'll see what the dyno says but possibly going from my 3400 stall to 4000 stall...STR of maybe 2.4? EDGE most likely.
Now....opinions guys....I THINK the dual cut outs will suffice. The guy on LS1tech dyno'ed at 422rwhp around 6200 RPM. I think since I have more cubes and he has the M6, they will cancel each other out in regards to dyno numbers but I think I'll peak around 5800 RPM.
But I am debating between the Speed Engineering true 3 inch duals for LS1/LT1s and having an exhaust shop make it work OR Hawks 4 inch Sinister exhaust with a Hooker Maxflow muffler (wished there was a 4 inch Aerochamber muffler)
I am junking the hedmen 1 5/8 longtubes and going with Dyno Don shorties with dual 2.5 inch cut outs.
I'll see what the dyno says but possibly going from my 3400 stall to 4000 stall...STR of maybe 2.4? EDGE most likely.
Now....opinions guys....I THINK the dual cut outs will suffice. The guy on LS1tech dyno'ed at 422rwhp around 6200 RPM. I think since I have more cubes and he has the M6, they will cancel each other out in regards to dyno numbers but I think I'll peak around 5800 RPM.
But I am debating between the Speed Engineering true 3 inch duals for LS1/LT1s and having an exhaust shop make it work OR Hawks 4 inch Sinister exhaust with a Hooker Maxflow muffler (wished there was a 4 inch Aerochamber muffler)
#3
Supreme Member
Re: Speed Engineering True Duals vs Hawks Sinister 4 inch
You want to run all that cam and head work through shorty exhaust?
#4
Re: Speed Engineering True Duals vs Hawks Sinister 4 inch
https://www.thirdgen.org/forums/exha...long-tube.html
https://www.thirdgen.org/forums/tpi/...ip-into-2.html
First post compares a slightly modified Dyno Don short tube header vs 1 3/4 longtube on a dyno
Second post is a member who also ran Dyno Don headers and a 3.5 inch cutout with success. Both members are at my power level. So yes, I will give up the 20 hp from 2000 RPM and the 10ish HP at 5000 for better ground clearance.
#5
Re: Speed Engineering True Duals vs Hawks Sinister 4 inch
See above posts. I also do not want to give up what little bit of ground clearance I have now for the slight horsepower I would gain from scraping on all the speedbumps and my inclined driveway.
Edit: I do not know how to weld, however, I am not against going to a diesel truck exhaust place here to make a 4 inch exhaust either...that is also an option. But since that would be a custom job, each member who made their own 4 inch fatback would have a different ground clearance, which is important to me.
Trending Topics
The following users liked this post:
8Mike9 (04-23-2020)
#9
Senior Member
iTrader: (1)
Re: Speed Engineering True Duals vs Hawks Sinister 4 inch
Do the single 4". I have don's headers on my 383, using the mufflex 4" (same as the sinister) with a spintech muffler. It sounds amazing. My car sits pretty low, but overall, the ground clearance in manageable, all things considered. You'll need to get a panhard bar drop bracket/brace for it to clear, and it does run extremely close to the fuel tank. I added some heat shielding to my tank to help it out some.
The following users liked this post:
89formula350b2l (04-30-2020)
#10
Supporter/Moderator
iTrader: (7)
Join Date: Feb 2001
Location: Cincinnati, OH
Posts: 13,260
Likes: 0
Received 394 Likes
on
300 Posts
Car: '90 RS
Engine: 377 LSX
Transmission: Magnum T56
Re: Speed Engineering True Duals vs Hawks Sinister 4 inch
Either system will suffice, since your choking point will be the y-pipe. Not sure how well a true dual system would work on a shorty set-up. Seems like there would be some wonky fab work to make it work. I'd just go single exhaust.
#11
COTM Editor
iTrader: (22)
Join Date: Mar 2001
Posts: 9,944
Likes: 0
Received 1,872 Likes
on
1,280 Posts
Car: '89 Firebird
Engine: 7.0L
Transmission: T56
Re: Speed Engineering True Duals vs Hawks Sinister 4 inch
Either exhaust will work. I would do the one that you think better fits in your car. If you go with a single exhaust then I suggest using a Flowmaster merge to get the most out of it. That means you'll be making a custom Y-pipe, but you'll be doing that anyway if you want things to work well.
If you haven't bought the headers already then I'd do the long tubes hands down. 30 lb-ft difference in the link you provided earlier. That's a lot! No reason why you can't have good ground clearance with long tubes, just buy smart.
If you haven't bought the headers already then I'd do the long tubes hands down. 30 lb-ft difference in the link you provided earlier. That's a lot! No reason why you can't have good ground clearance with long tubes, just buy smart.
Last edited by QwkTrip; 04-23-2020 at 04:32 PM.
#12
Supporter/Moderator
iTrader: (7)
Join Date: Feb 2001
Location: Cincinnati, OH
Posts: 13,260
Likes: 0
Received 394 Likes
on
300 Posts
Car: '90 RS
Engine: 377 LSX
Transmission: Magnum T56
Re: Speed Engineering True Duals vs Hawks Sinister 4 inch
If you haven't bought the headers already then I'd do the long tubes hands down. 30 lb-ft difference in the link you provided earlier. That's a lot! No reason why you can't have good ground clearance with long tubes, just buy smart. And if you end up with a single exhaust then use a Flowmaster merge.
#13
Re: Speed Engineering True Duals vs Hawks Sinister 4 inch
Either exhaust will work. I would do the one that you think better fits in your car. If you go with a single exhaust then I suggest using a Flowmaster merge to get the most out of it. That means you'll be making a custom Y-pipe, but you'll be doing that anyway if you want things to work well.
If you haven't bought the headers already then I'd do the long tubes hands down. 30 lb-ft difference in the link you provided earlier. That's a lot! No reason why you can't have good ground clearance with long tubes, just buy smart.
If you haven't bought the headers already then I'd do the long tubes hands down. 30 lb-ft difference in the link you provided earlier. That's a lot! No reason why you can't have good ground clearance with long tubes, just buy smart.
30ftlbs of torque difference? Where? At 3500 RPM where I will launch from? And then that's it...a lot of PITA work for the launch which i believe will be negated (at least partially) by upgrading stall to 4000 anyways. Thinking 2.4 str
#14
COTM Editor
iTrader: (22)
Join Date: Mar 2001
Posts: 9,944
Likes: 0
Received 1,872 Likes
on
1,280 Posts
Car: '89 Firebird
Engine: 7.0L
Transmission: T56
Re: Speed Engineering True Duals vs Hawks Sinister 4 inch
Another option is a single 3.5" exhaust. Little easier to package and doesn't require reworking the panhard bar.
#15
Re: Speed Engineering True Duals vs Hawks Sinister 4 inch
Also, I am considering the option open of running a 100 wet shot and do not want to buy another catback if I decide to put the nitrous on there.
#17
Supporter/Moderator
iTrader: (7)
Join Date: Feb 2001
Location: Cincinnati, OH
Posts: 13,260
Likes: 0
Received 394 Likes
on
300 Posts
Car: '90 RS
Engine: 377 LSX
Transmission: Magnum T56
Re: Speed Engineering True Duals vs Hawks Sinister 4 inch
Sorry I should have elaborated. They will be releasing a new set that follows the Blackheart line and will work with their Blackheart dual system. They are much better designed to allow maximum ground clearance. There are a few threads on here where a Holley rep details these.
#18
Supreme Member
Re: Speed Engineering True Duals vs Hawks Sinister 4 inch
I won't get into the long vs short debate as I respect your request not to.
Regarding the 30 ft/lbs difference though, it's more like 30 X 3.06(1st gear) X 3.73(rear gear) at the launch. That's an additional 342 ft/lbs to get your car rolling. And the 30 ft/lbs doesn't account for any tuning (if my recollection of the posted threads is accurate). Just the header comparison.
All of that said, I think the reference to personal choice especially regarding the overall sound quality, both in tone and volume, will probably be a determining factor.
Regarding the 30 ft/lbs difference though, it's more like 30 X 3.06(1st gear) X 3.73(rear gear) at the launch. That's an additional 342 ft/lbs to get your car rolling. And the 30 ft/lbs doesn't account for any tuning (if my recollection of the posted threads is accurate). Just the header comparison.
All of that said, I think the reference to personal choice especially regarding the overall sound quality, both in tone and volume, will probably be a determining factor.
Last edited by skinny z; 04-25-2020 at 08:52 AM.
The following users liked this post:
89formula350b2l (04-25-2020)
#19
COTM Editor
iTrader: (22)
Join Date: Mar 2001
Posts: 9,944
Likes: 0
Received 1,872 Likes
on
1,280 Posts
Car: '89 Firebird
Engine: 7.0L
Transmission: T56
Re: Speed Engineering True Duals vs Hawks Sinister 4 inch
There's a member here by the name of firebrdo88 that runs 9's through a 3.5" exhaust with a 200 shot of nitrous. Got to be putting down a good 700 RWHP.
#22
Re: Speed Engineering True Duals vs Hawks Sinister 4 inch
I won't get into the long vs short debate as I respect your request not to.
Regarding the 30 ft/lbs difference though, it's more like 30 X 3.06(1st gear) X 3.73(rear gear) at the launch. That's an additional 342 ft/lbs to get your car rolling. And the 30 ft/lbs doesn't account for any tuning (if my recollection of the posted threads is accurate). Just the header comparison.
All of that said, I think the reference to personal choice especially regarding the overall sound quality, both in tone and volume, will probably be a determining factor.
Regarding the 30 ft/lbs difference though, it's more like 30 X 3.06(1st gear) X 3.73(rear gear) at the launch. That's an additional 342 ft/lbs to get your car rolling. And the 30 ft/lbs doesn't account for any tuning (if my recollection of the posted threads is accurate). Just the header comparison.
All of that said, I think the reference to personal choice especially regarding the overall sound quality, both in tone and volume, will probably be a determining factor.
I appreciate that good sir. There are a few factors why I am going shorty...one I don't see the performance as being that much difference (opinions and I respect yours), ground clearance and the fact that my driveway is on an incline. If I was made of money or the Marine Corps paid me enough, I would do back to back not only dyno's but runs at the track. Having to have catalytic converters for the visual state inspection is also a factor. The exhaust shop that did the custom y pipe for the Hedman longtubes did not do a great job but it was the only shop willing to tackle the job so I was kinda stuck.
my goal with the car was originally mid 11s (11.7x to 11.5x). If I only get to 11.8x it's meh. I'm not going to professionally race this or anything. It's more of personal pride than anything.
#23
Supreme Member
Re: Speed Engineering True Duals vs Hawks Sinister 4 inch
I appreciate that good sir. There are a few factors why I am going shorty...one I don't see the performance as being that much difference (opinions and I respect yours), ground clearance and the fact that my driveway is on an incline. If I was made of money or the Marine Corps paid me enough, I would do back to back not only dyno's but runs at the track. Having to have catalytic converters for the visual state inspection is also a factor. The exhaust shop that did the custom y pipe for the Hedman longtubes did not do a great job but it was the only shop willing to tackle the job so I was kinda stuck.
my goal with the car was originally mid 11s (11.7x to 11.5x). If I only get to 11.8x it's meh. I'm not going to professionally race this or anything. It's more of personal pride than anything.
my goal with the car was originally mid 11s (11.7x to 11.5x). If I only get to 11.8x it's meh. I'm not going to professionally race this or anything. It's more of personal pride than anything.
The following users liked this post:
89formula350b2l (04-25-2020)
#24
Member
iTrader: (1)
Re: Speed Engineering True Duals vs Hawks Sinister 4 inch
Sorry I should have elaborated. They will be releasing a new set that follows the Blackheart line and will work with their Blackheart dual system. They are much better designed to allow maximum ground clearance. There are a few threads on here where a Holley rep details these.
Thread
Thread Starter
Forum
Replies
Last Post