Supercharged 2001 c5 lower than expected power
Thread Starter
Heel & Toe
Joined: Jan 2020
Posts: 16
Likes: 7
Supercharged 2001 c5 lower than expected power
Good Afternoon.
I have a 2001 6 speed coupe with 30k miles that baselined 316 RWHP and 340 RWTQ before the A&A Supercharger. All stock except K&N intake and a Corsa Sport axle back.
I brought the vehicle to a well known corvette shop and after the A&A supercharger only it made 488 RWHP and 440 RWTQ.
Both the shop and myself were a bit disappointed, so we decided to add ARH 1 7/8 long tube headers, x pipe and a clutch since the stock one was angry.
The car picked up 3 RWHP and zero RWTQ.
I have yet to pick the car up, and I do not wish to name or speak ill of the shop, however something seems amiss as I was expecting ~530-550 RWHP total, and headers should add 20 - 30 RWHP plus area under the curve.
The head unit is a v3 ti on the 3.6" pulley.
Hp tuners shows plenty of fuel and injector, a/f stays right at 12.0, and 12* of timing. 93 octane non ethanol fuel.
I am not looking to run right on the ragged edge, and plan on driving the car quite a bit, so safe is good, but I was still expecting more.
Any thoughts on what I should have the shop look at prior to picking it up?
Thank you for reading.
I have a 2001 6 speed coupe with 30k miles that baselined 316 RWHP and 340 RWTQ before the A&A Supercharger. All stock except K&N intake and a Corsa Sport axle back.
I brought the vehicle to a well known corvette shop and after the A&A supercharger only it made 488 RWHP and 440 RWTQ.
Both the shop and myself were a bit disappointed, so we decided to add ARH 1 7/8 long tube headers, x pipe and a clutch since the stock one was angry.
The car picked up 3 RWHP and zero RWTQ.
I have yet to pick the car up, and I do not wish to name or speak ill of the shop, however something seems amiss as I was expecting ~530-550 RWHP total, and headers should add 20 - 30 RWHP plus area under the curve.
The head unit is a v3 ti on the 3.6" pulley.
Hp tuners shows plenty of fuel and injector, a/f stays right at 12.0, and 12* of timing. 93 octane non ethanol fuel.
I am not looking to run right on the ragged edge, and plan on driving the car quite a bit, so safe is good, but I was still expecting more.
Any thoughts on what I should have the shop look at prior to picking it up?
Thank you for reading.
Last edited by neubauej; Oct 3, 2020 at 12:59 PM.
Melting Slicks
Joined: Jul 2014
Posts: 2,356
Likes: 359
From: Virginia
If the shop cant figure it out for you then you need a different shop.
What injectors? What type of dyno? What were the temp, humidity and altitude?
Is there any black dust on/around the blower bracket?
Do you have the logs and/or dyno sheet?
Did they pull and check the plugs? Compression test? Leakdown test? Boost leak test?
488 rwhp seems low but not outside the realm of possibility depending on a number of factors. The 3rwhp after adding headers makes me skeptical and think something isnt right.
Edit: just realized you said v3 ti and not si. 488 is low. Are you in a stock fuel pump and wiring?
What injectors? What type of dyno? What were the temp, humidity and altitude?
Is there any black dust on/around the blower bracket?
Do you have the logs and/or dyno sheet?
Did they pull and check the plugs? Compression test? Leakdown test? Boost leak test?
488 rwhp seems low but not outside the realm of possibility depending on a number of factors. The 3rwhp after adding headers makes me skeptical and think something isnt right.
Edit: just realized you said v3 ti and not si. 488 is low. Are you in a stock fuel pump and wiring?
Last edited by Turpid porpoise; Oct 3, 2020 at 01:35 PM.
Banned Scam/Spammer
Joined: May 2007
Posts: 15,685
Likes: 1,330
From: Machineguns, because I don’t compromise
The fact it picked up nearly nothing after a header install shows the issue is tuning.
The shop has a weak person tuning the car.
Take the car elsewhere for a better tune even if it means traveling outside the local area.
The shop has a weak person tuning the car.
Take the car elsewhere for a better tune even if it means traveling outside the local area.
Thread Starter
Heel & Toe
Joined: Jan 2020
Posts: 16
Likes: 7
Thank you all for your replies.
To answer a few questions,
60# Siemens Deka Injectors
Dynojet, SAE Smoothing 5
1,000' elevation, Weather on Friday when tuning was 76 degrees, 56% humidity.
No black dust on or around the blower bracket, nor any other sign of belt slippage.
The Plugs look good, boost leak test performed, no leaks. I don't believe they have performed a compression or leakdown test, but I will once i receive the car back.
I do not have the logs or dyno sheet currently, but will once I pickup the car.
I believe doing a compression and leakdown test make the most sense, and assuming that looks like a 30k mile motor should, will need to find another tuner familiar with boosted ls1's.
Any good suggestions around Mpls/St Paul or Chicago? I live in the middle of nowhere in northern Wisconsin, so travel is expected.
To answer a few questions,
60# Siemens Deka Injectors
Dynojet, SAE Smoothing 5
1,000' elevation, Weather on Friday when tuning was 76 degrees, 56% humidity.
No black dust on or around the blower bracket, nor any other sign of belt slippage.
The Plugs look good, boost leak test performed, no leaks. I don't believe they have performed a compression or leakdown test, but I will once i receive the car back.
I do not have the logs or dyno sheet currently, but will once I pickup the car.
I believe doing a compression and leakdown test make the most sense, and assuming that looks like a 30k mile motor should, will need to find another tuner familiar with boosted ls1's.
Any good suggestions around Mpls/St Paul or Chicago? I live in the middle of nowhere in northern Wisconsin, so travel is expected.
Le Mans Master
Joined: Jul 2010
Posts: 6,021
Likes: 727
Personal experience, friend had literally same set up except and better fuel system, 80 inj and a p1 procharger. 12psi boost he had 550rwh. I know all set ups are different but the timing seems low he had 17. 93 oct. 11.6afr
And another thing, usually you get 20 30ish hp per 1 degree of timing, so lets say on the low end 20hp add 4 = 80 hp gain which puts you into the range that's excepted. I know i know but it makes sense.
And another thing, usually you get 20 30ish hp per 1 degree of timing, so lets say on the low end 20hp add 4 = 80 hp gain which puts you into the range that's excepted. I know i know but it makes sense.
Last edited by helga203; Oct 4, 2020 at 11:34 AM.
Le Mans Master
Joined: Jul 2010
Posts: 6,021
Likes: 727
Thank you all for your replies.
To answer a few questions,
60# Siemens Deka Injectors
Dynojet, SAE Smoothing 5
1,000' elevation, Weather on Friday when tuning was 76 degrees, 56% humidity.
No black dust on or around the blower bracket, nor any other sign of belt slippage.
The Plugs look good, boost leak test performed, no leaks. I don't believe they have performed a compression or leakdown test, but I will once i receive the car back.
I do not have the logs or dyno sheet currently, but will once I pickup the car.
I believe doing a compression and leakdown test make the most sense, and assuming that looks like a 30k mile motor should, will need to find another tuner familiar with boosted ls1's.
Any good suggestions around Mpls/St Paul or Chicago? I live in the middle of nowhere in northern Wisconsin, so travel is expected.
To answer a few questions,
60# Siemens Deka Injectors
Dynojet, SAE Smoothing 5
1,000' elevation, Weather on Friday when tuning was 76 degrees, 56% humidity.
No black dust on or around the blower bracket, nor any other sign of belt slippage.
The Plugs look good, boost leak test performed, no leaks. I don't believe they have performed a compression or leakdown test, but I will once i receive the car back.
I do not have the logs or dyno sheet currently, but will once I pickup the car.
I believe doing a compression and leakdown test make the most sense, and assuming that looks like a 30k mile motor should, will need to find another tuner familiar with boosted ls1's.
Any good suggestions around Mpls/St Paul or Chicago? I live in the middle of nowhere in northern Wisconsin, so travel is expected.
Last edited by helga203; Oct 4, 2020 at 11:47 AM.
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Safety Car
Joined: Feb 1999
Posts: 4,044
Likes: 342
From: Central NJ
Thank you all for your replies.
To answer a few questions,
60# Siemens Deka Injectors
Dynojet, SAE Smoothing 5
1,000' elevation, Weather on Friday when tuning was 76 degrees, 56% humidity.
No black dust on or around the blower bracket, nor any other sign of belt slippage.
The Plugs look good, boost leak test performed, no leaks. I don't believe they have performed a compression or leakdown test, but I will once i receive the car back.
I do not have the logs or dyno sheet currently, but will once I pickup the car.
I believe doing a compression and leakdown test make the most sense, and assuming that looks like a 30k mile motor should, will need to find another tuner familiar with boosted ls1's.
Any good suggestions around Mpls/St Paul or Chicago? I live in the middle of nowhere in northern Wisconsin, so travel is expected.
To answer a few questions,
60# Siemens Deka Injectors
Dynojet, SAE Smoothing 5
1,000' elevation, Weather on Friday when tuning was 76 degrees, 56% humidity.
No black dust on or around the blower bracket, nor any other sign of belt slippage.
The Plugs look good, boost leak test performed, no leaks. I don't believe they have performed a compression or leakdown test, but I will once i receive the car back.
I do not have the logs or dyno sheet currently, but will once I pickup the car.
I believe doing a compression and leakdown test make the most sense, and assuming that looks like a 30k mile motor should, will need to find another tuner familiar with boosted ls1's.
Any good suggestions around Mpls/St Paul or Chicago? I live in the middle of nowhere in northern Wisconsin, so travel is expected.
Former Vendor
Joined: Feb 2012
Posts: 26,512
Likes: 351
From: ST. CHARLES IL
12 degrees of timing is not enough to make power. That is very low especially on an LS1 car. Hit us up, we have plenty of A&A cars in the 500-700rwhp range. With a 3.6 pulley and headers you should be in the 500s.
Pro
Joined: Mar 2005
Posts: 721
Likes: 70
From: Fla
had a 2000 coupe automatic c5, with vortech blower and 60 pound injectors and a blower cam, car made 503 safely on mustang dyno. automatics dyno much lower because of the converter and valve train loss. my automatic, with long tube headers, blower without cam was 465, cam brought it quite a bit to 503 all on mustang dynos which do not give high numbers compared to dynojet dyno. I dont think you are that far off for stock cam ls1. my automatic base lines 295 rwhp with long tub headers, z06 intake and tune before blower and blower cam installed.
Melting Slicks
Joined: Jul 2014
Posts: 2,356
Likes: 359
From: Virginia
had a 2000 coupe automatic c5, with vortech blower and 60 pound injectors and a blower cam, car made 503 safely on mustang dyno. automatics dyno much lower because of the converter and valve train loss. my automatic, with long tube headers, blower without cam was 465, cam brought it quite a bit to 503 all on mustang dynos which do not give high numbers compared to dynojet dyno. I dont think you are that far off for stock cam ls1. my automatic base lines 295 rwhp with long tub headers, z06 intake and tune before blower and blower cam installed.
Safety Car
Joined: Feb 1999
Posts: 4,044
Likes: 342
From: Central NJ
Just a qq or two.....what timing do you feel is safe for a stock engine (with headers) automatic tranny? And at what rpm are we taking here for 12 degrees? My car is at 13 degrees for the most part are WOT and higher rpms.....Do you think I have some room here? I do have HP tuners and do know how to use it, but you did comment on this matter....Just wanted a professional opinion....Thanks
Melting Slicks
Joined: Nov 2017
Posts: 2,306
Likes: 747
I agree on it being the tuner. Your scenario was sounding exactly like mine to the point that I looked at the username at least twice to make sure it wasn't one of my past posts LOL.Then I realized there were several key differences that should have you making much more power. 12psi on a T-trim with headers and 93 octane should put you in at least the mid 500s. Unless your tuner is keeping you at 12 degrees for a specific reason, there's room to bump that up safely as others have said.
I was going to ask if you've replaced your rear gears with something steeper, because that would be a good reason for it reading low, but your baseline numbers say otherwise.
I was going to ask if you've replaced your rear gears with something steeper, because that would be a good reason for it reading low, but your baseline numbers say otherwise.
Pro
Joined: Mar 2005
Posts: 721
Likes: 70
From: Fla
I just realized his was a 6speed car. he should dyno with headers and blower stock cam 530... on chassis mustang dyno. like i said my automatic car lost lots on dyno because of the converter. the header thing is strange.. 3 horse is not enough maybe 20-25 horse with longtube header gain.