Guess the HP - H/C car
Guess the HP - H/C car So Im going to the dyno this saturday for tuning. As such I have the classic "what will it make" obsessive syndrome. I figured I could start a thread and let people guess and then we can all see how close the guesses were after I come back.
Heres whats done to it:
Stock LS1 bottom end
TFS as Cast 220 heads cleaned up by BTR
BTR Stage 2 Cam (227/234 .624/.576 113+2)
Fast 90/90
42Lb injectors
Long tube 1 7/8 headers
MAF-less intake setup
Dual 2.5Inch exhaust
T56
HP Tuners tune to come
Its going onto a Dynojet, and its sitting inside of an IRS Rx7. So... what will it make? I'm thinking 420-440whp? What do you all think?
Heres whats done to it:
Stock LS1 bottom end
TFS as Cast 220 heads cleaned up by BTR
BTR Stage 2 Cam (227/234 .624/.576 113+2)
Fast 90/90
42Lb injectors
Long tube 1 7/8 headers
MAF-less intake setup
Dual 2.5Inch exhaust
T56
HP Tuners tune to come
Its going onto a Dynojet, and its sitting inside of an IRS Rx7. So... what will it make? I'm thinking 420-440whp? What do you all think?
Frist advice I can give you is don't be too upset if you get a low number on the dyno. Just because it's a DynoJet doesn't mean anything. All DynoJets are going to read differently due to a lot of reasons. I think that setup you have should produce around 450 rwph and maybe more. Those are outstanding heads, and if Brian hand worked them, then they're even better. Cam is not big by any means, but isn't small either. The FAST 90/90 is good and your headers are great. The 2.5" duals are obviously a restriction over 3" duals, but you've got limited room due to what car this is going in. In that light weight of a car, even if you only make around 430 to 440, you'll still be outrunning heavier cars that make more power.
Well, went to the dyno today. Looks like everyone was estimating much too high. Myself as well. In my setups defense, it was 95* with 55% humidity here today. Probably some of the worst conditions to dyno during.
Ended up with 404whp / 373ft/lbs. I'm a bit saddened its so low, but will make a trip to the drag strip and see what it does there. I'll also be at LsFest in a few weeks. I'm hoping it wont be so crazy hot that day and I can do some pulls on the dyno and see if I pick up some power by virtue of it not being horrible outside.
Ended up with 404whp / 373ft/lbs. I'm a bit saddened its so low, but will make a trip to the drag strip and see what it does there. I'll also be at LsFest in a few weeks. I'm hoping it wont be so crazy hot that day and I can do some pulls on the dyno and see if I pick up some power by virtue of it not being horrible outside.
I'm surprised. Seems like you should have made a bunch more than that. Those were uncorrected numbers?
Not knowing what your elevation or local barometric pressure is, your corrected number could be anywhere from 411 to 422.
Not knowing what your elevation or local barometric pressure is, your corrected number could be anywhere from 411 to 422.
Last edited by 1970camaroRS; Aug 24, 2014 at 04:08 AM.
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Honestly this doesn't surprise me at all! Mine made about the same as yours OP, but it runs with 450-500 rwhp cars of similar weight, gearing, drivers, etc...don't be discouraged just yet 
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i've made 488, 499, and 520rwhp all on 3 different dynojets in my town, that's a 32rwhp difference all from just a different dyno... numbers mean jack... dynos are for tuning not ego boosts... i bet your rx7 runs great with that combo and would give me quite the close race
So, the car goes ~94mph in the 1/8th mile. Before the heads, fast, and larger cam it did 91, occassionally 92mph. That was back when it dyno'ed 345whp. Seems like I'm a bit down in my mind still.
In searching, I noticed that the pushrods I got from BTR were 7.5 long. I got a pushrod measuring tool and measured. With no pre-load it came to 7.33. I figure add a bit for preload and that takes me to about 7.4. I had 7.4's from my previous setup so I threw them in there. I havent gotten to do any tuning or dyno runs yet with it. I'm wondering though, would a pushrod thats .1 too long cause it to be down on power?
In searching, I noticed that the pushrods I got from BTR were 7.5 long. I got a pushrod measuring tool and measured. With no pre-load it came to 7.33. I figure add a bit for preload and that takes me to about 7.4. I had 7.4's from my previous setup so I threw them in there. I havent gotten to do any tuning or dyno runs yet with it. I'm wondering though, would a pushrod thats .1 too long cause it to be down on power?
Last edited by crash41301; Sep 21, 2014 at 09:55 PM.
You went from 345 to 404?
Of so that's a very solid pick up. Mph did not pick up enough though.
What's you whole slip look like?
Also do you have a graph of the new run and possible a graph of both overlayed?
Of so that's a very solid pick up. Mph did not pick up enough though.
What's you whole slip look like?
Also do you have a graph of the new run and possible a graph of both overlayed?
Here is the before and after dyno runs.
You think jumping only 35whp is a good gain?
I upgraded from
-100% stock ls1 heads to TFS heads
-224/224 to 227/234 cam with more lift
-stock ls1 intake manifold to fast 90/90
Either theres lots of mis-information out there about what these kinds of mods will net or I'm way off here? Seems like a few of those mods would do nearly that by themselves based on what I always read on this forum.
You think jumping only 35whp is a good gain?
I upgraded from
-100% stock ls1 heads to TFS heads
-224/224 to 227/234 cam with more lift
-stock ls1 intake manifold to fast 90/90
Either theres lots of mis-information out there about what these kinds of mods will net or I'm way off here? Seems like a few of those mods would do nearly that by themselves based on what I always read on this forum.
Last edited by crash41301; Aug 31, 2014 at 08:38 PM.
Tuning was done by a local tuner. I trust him, and having done a decent amount of tuning myself he followed the same methodology I've done and saw most every other tuners do. Effectively, get the AF lined out and even, then adjust timing up/down to find MBT. Then play with AF a bit to see if power goes up or down. If it does, repeat timing adjustments a bit. I've got the HPT tune files and VCM Scanner files from the runs if anyone thinks they would help? A/F was ~12.8 across the rpm range with timing 25-26*.
Sounds cheesy, but I actually cleaned my car out to prepare for the LSfest trip and threw all the "misc junk paper" away in the back seat area. That apparently included all the white timeslips I had
From memory, my best 60ft was 1.89, with most being high 1.9s. My best ET was 7.8 with most being low 8's and my MPH's were 92-94. Does that help? Last edited by crash41301; Aug 31, 2014 at 09:14 PM.
I did the install work. Been working on cars for 14yrs, so while its possible i did something wrong Im at least not your run of the mill idiot
any suggestions on things to check? Ive went down the check the pushrods path, Im thinking of doing a compression test as well.
any suggestions on things to check? Ive went down the check the pushrods path, Im thinking of doing a compression test as well.
